Fluoridation and child IQ – the problem of counting chickens before they hatch

It’s easy to find studies that confirm ones own bias on health issues. But cherry-picking such studies is unscientific because one could equally cite studies showing the exact opposite. The problem is these studies often rely on poor data, do not sufficiently account for confounding factors and often use poor statistical analysis so contradictory results are inevitable. A more objective requires a meta-analysis of all the available studies.

Anti-fluoride activists do this when they cherry-pick studies to argue that science has “proved” fluoride intake by pregnant women lowers the IQ of their children. These activists rely on just a few studies from two related groups – they cite Bashash et al (2107), Green et al (2019) and Till et al (2020). But what about studies that show the exact opposite – an increase in child IQ and the low fluoride intake relevant to community water fluoridation. Studies they ignore like those of Santa-Marina et al (2019) and Ibarluzea et al (2020).

The publication this month of new extensive data from an important study will be harder to ignore. This establishes a relationship of prenatal maternal intake of fluoride with the cognitive results for children in areas of Spain where community water fluoridation is used. In contrast to the negative results found in the studies anti-fluoride activists rely on, this new study reported: “Maternal fluoride levels were associated with better cognitive scores in childhood.”

Here is the citation for the new study:

Ibarluzea, J., Gallastegi, M., Santa-Marina, L., Jiménez Zabala, A., Arranz, E., Molinuevo, A., Lopez-Espinosa, M.-J., Ballester, F., Villanueva, C. M., Riano, I., Sunyer, J., Tardon, A., & Lertxundi, A. (2021). Prenatal exposure to fluoride and neuropsychological development in early childhood: 1-to 4 years old children. Environmental Research, 112181.

The figure below summarises the results for relationships of child cognitive scores with maternal prenatal urine – a measure of fluoride intake. cognitive scores are from McCarthy Scales tests appropriate for age 4. GCI is a General Cognitive Index.

The data points are for ß coefficients of the linear regressions of cognitive score against material urinary fluoride – the slope in units of amount of cognitive change per unit of urinary F (mg/L or equivalent). The bars are the 95% confidence intervals – if they include zero in the range this indicates the score is not beta value for the score is not statistically significant.

As we can see all the cognitive scores a positive and statistically significant for boys – hence the conclusion that “Maternal fluoride levels were associated with better cognitive scores in childhood.” However, none of the changes in scores for girls was statically different from zero

Don’t get me wrong. I am certainly not arguing that maternal intake of fluid will increase the cognitive levels of offspring male children. I am not attempting to confirm a pro-fluoride bias here. Remember, I said that objective assessment requires a meta-analysis of all the available studies.

The figure below shows the results of a meta-analysis of all the available studies which considered the relationship of the cognitive score with prenatal maternal urinary F.

As we can see, some of the beta values are positive and some are negative. Many are not significantly different from zero – any effect is not statistically signficant. Over all the studies, on average the score is positive (ß = 2.1 for 1 mg/L increase in urinary fluoride, or the equivalent measure) but not statistically significant from zero (95% confidence level is -1.9 to 6.1).

So the best objective conclusion to date is that child cognitive scores are not influenced by prenatal maternal fluoride intake at the levels expected in these studies which are relevant to community water fluoridation.

Conclusion

These studies illustrate the danger of cherry-picking studies to draw conclusions. or even simply taking the data from only a few studies that have so far been published. But that is what Grandjean et al (2021) have done in the benchmark analysis of cherry-picked studies. They concluded that a safe level for maternal urinary fluoride is as low as about 0.2 mg/l.

Image credit: Cherry-Picking

At best they counted their chickens before they had hatched, given that some important studies had not been published in scientific journals. At worst the cherry-picked to confirm a bias.

I suspect the latter because the important Spanish data had been published as conference papers so they should have been aware of them. The authors of the benchmark paper are all associated with the limited number of studies they considered (particularly those of Bashash et al (2107), Green et al (2019) and Till et al (2020)) and were members of just two groups obviously coordinating their work. Authors from this group have been very active in promoting their own findings, studiously ignoring the findings of voters and also using their work to promote the arguments of anti-fluoride activists against community water fluoridation.

Just imagine if some pro-fluoride activists chose to claim that fluoridation will actually increase child IQ and cherry-picked the Spanish studies to support their claim. I can’t actually see that happening, but if it did it would be as bad as the approach used by the authors of  Grandjean et al (2021).

This tactic of cherry-picking studies may be used to provide a scientific basis for activist arguments – but that is not true science.

Similar articles

August ’21 – NZ blogs sitemeter ranking

Sadly, this will be my last post of NZ blog rankings.

I have been doing this for quite a while and it will be sad to let it go. Many might say that blogs are no longer as important as they were some years back. Other forms of social media have taken over.

I think that argument has some validity but that is not the reason for my decision to pack it in. The real problem is my health. A had a minor stroke a year ago and have since found writing, and computer use, very difficult. This sort of activity is quite frustrating for me (I tend to end up swearing a lot) and it’s not helped by the way software nerds update things, forcing me to undergo the extra frustrations of learning new tricks simply to do the old things in the ways which were more comfortable.

Hopefully giving up a few jobs like this will remove some of the unhealthy frustrations. I hope to attempt other writing on my blog (it’s supposed to be good for me) but we will see. 

I anyone else is interested in carrying on this regular blog ranking please feel free to do so.


 

Here are the rankings of New Zealand blogs with publicly available statistics for July 2021. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings Subscribe to NZ blog rankings by Email Find out how to get Subscription & email updates

Rank Blog Visits/month Page Views/month

1

The Daily Blog

66517

393825

2

Liturgy

23356

29939

3

13th Floor

16755

18458

4

Tikorangi: The Jury Garden

13576

15170

5

SciBlogs

9996

19862

6

Cycling in Christchurch

9842

10737

7

Homepaddock

8571

9413

8

Bill Bennett

8390

9017

9

Sacraparental

7069

8101

10

Creative Maths

5595

6775

11

Offsetting behaviour

4290

4873

12

Woodleigh Nursery

3738

6527

13

Free range statistics

3535

5073

14

Music of sound

3387

4592

15

The Meaning of Trees

2151

3372

16

Lost in silver fern

1962

3152

17

Jontynz

1759

2229

18

Nom Nom Panda

1660

1768

19

Sarah the Gardener

1429

1932

20

Fields of Blood

1327

1575

21

Anglican down under

1238

1619

22

Talking Auckland

1212

1382

23

No Minister

1058

1159

24

The Global Couple

1053

1160

25

Reading the maps

1041

1457

26

Open Parachute

1007

1132

27

The Woolshed Wargamer

968

2007

28

Pdubyah – a life just as ordinary

765

923

29

Muffin-Mum

738

783

30

TVHE

706

4354

31

A communist at large

675

751

32

Rodney’s Aviation Ramblings

591

684

33

Hot Topic

498

550

34

Home education Foundation

461

570

35

AmeriNZ

447

643

36

Economics New Zealand

413

495

37

Tales from a Caffeinated Weka

397

420

38

Off the couch

365

472

39

Quote Unquote

308

324

40

Perissodactyla

297

320

41

Stratford Aerodrome

278

363

42

Vomkrieg

276

383

43

Climate Justice Taranaki

246

326

44

Mountains of Our Minds#

241

310

45

Aughts and Oughtisms

236

362

46

Kiwi Cakes

233

262

47

Communication, Church, Society

225

289

48

Mrs Cake

223

287

49

Sparrowhawk/Karearea

211

238

50

AnneKcam

182

236

51

Eye on the ICR

175

214

52

Tauranga Blog

174

174

53

Social Media & the 2014 Election

149

171

53

Creative Voice#

149

219

55

New Zealand Conservative

146

151

56

Aotearoa: A wider perspective

128

137

57

Media Sport and Other Rantings

125

129

58

Cambridge NZ

109

121

59

Room 5 @ Melville Intermediate School

96

151

60

John Macilree’s Weblog#

81

94

61

Save our Schools NZ

80

84

62

Cut your hair

77

79

63

Glennis’s Blog Page#

75

133

64

kiwi simplexity

73

73

64

Anne Free Spirit

73

113

66

The Catalyst

71

114

67

Room One @ Auroa School

68

82

68

goNZo Freakpower Brains Trust

65

65

69

Exile in New zealand

61

63

69

Get Out Gertrude!

61

62

71

Put ’em all on an island

50

56

72

Keeping Stock

45

47

73

University of Otago, Law Library Blog

44

53

74

James McKerrow – Surveyor 1834-1919#

41

46

75

Ideologically impure

39

48

76

Undeniably Atheist

35

38

77

My thinks

34

34

78

The Official Ebenezer Teichelmann Blog#

32

39

79

Unity Blog

30

37

80

MartinIsti Blog

27

29

81

John Macilree’s Blog

26

29

81

ElephaNZa

26

26

81

Quietly in the backgroud

26

29

84

Glenview 9

24

24

84

bread and pomegranates

24

43

86

Journey to a mini me

23

28

87

Dad4justice

21

27

87

Family integrity

21

21

87

Wokarella

21

25

90

Software development and stuff

19

19

90

Nelsonian’s life

19

25

92

Right Reason

18

18

93

Samuel Dennis

17

18

94

Room 24, 2012

16

16

95

In the back of the net

15

15

95

SmallTorque

15

16

97

The Well read Kitty

12

12

97

Look, Think, Make

12

12

99

sticK

11

11

99

Wellington Chic

11

11

99

Chris Jillet – Mountaineer#

11

14

102

Taradale Blog#

10

11

103

New Zealand Indian Fine Arts Society

9

9

103

ah! New Year’s Resolution

9

9

103

Blogger at Large

9

9

106

Carolyn’s blog

7

8

106

New Zealand female Firefighter calendar

7

7

108

Socialist Aotearoa

6

6

108

Warrington Taylor#

6

6

110

Albom Adventures

5

5

110

Misses Mac

5

5

112

Episto

4

4

112

kiwiincanberra

4

4

112

Sharlene says

4

4

112

Fun with Allergy Kids

4

4

116

Helen Heath

2

2

116

Lulastic

2

2

116

Lena talks beauty

2

2

116

Money can buy me happiness

2

4

116

Utopia – you are standing in it

2

2

116

Einstein Music Journal

2

2

122

The IT Countrey Justice

1

1

122

High voltage learning during the Christchurch earthquakes

1

1

122

Brennan McDonald

1

1

122

The Little Waaagh! That Could

1

1

122

Four seasons in one

1

1

122

Spratts

1

1

122

Snowrii

1

1

July ’21 – NZ blogs sitemeter ranking

Image credit: Nicole MamaNYC

I notice a few regulars no longer allow public access to the site counters. This may happen accidentally when the blog format is altered. If your blog is unexpectedly missing or the numbers seem very low please check this out. After correcting send me the URL for your site meter and I can correct the information in the database.

Similarly, if your blog data in this list seems out of whack, please check your site meter. Usually, the problem is that for some reason your site meter is no longer working.

Sitemeter is no longer working so the total number of NZ blogs in this list has been drastically reduced. I recommend anyone with Sitemeter consider transferring to one of the other meters. See  NZ Blog Rankings FAQ.

This list is compiled automatically from the data in the various site meters used. If you feel the data in this list is wrong could you check to make sure the problem is not with your own site meter? I am of course happy to correct any mistakes that occur in the automatic transfer of data to this list but cannot be responsible for the site meters themselves. They do play up.

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters. Please note, the system is automatic and relies on blogs having sitemeters that allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for July 2021. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers. Meanwhile, I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings Subscribe to NZ blog rankings by Email Find out how to get Subscription & email updates

Rank Blog Visits/month Page Views/month

1

The Daily Blog

81001

355065

2

13th Floor

28136

31289

3

Liturgy

16923

215402

4

Tikorangi: The Jury Garden

10898

12269

5

SciBlogs

10000

19429

6

Bill Bennett

9824

10838

7

Homepaddock

8550

9455

8

Cycling in Christchurch

6673

7427

9

Creative Maths

5300

6455

10

Sacraparental

4617

5396

11

Offsetting behaviour

3769

4396

12

Free range statistics

3375

4971

13

Music of sound

3358

4194

14

Lost in silver fern

3127

5111

15

Woodleigh Nursery

2725

4344

16

Jontynz

2093

2515

17

Nom Nom Panda

1759

1880

18

Fields of Blood

1567

1782

19

The Meaning of Trees

1235

2909

20

Anglican down under

1221

1494

21

Sarah the Gardener

1176

1551

22

The Global Couple

1134

1230

23

Reading the maps

1116

1732

24

The Woolshed Wargamer

960

1751

25

Talking Auckland

948

1126

26

No Minister

935

1031

27

Open Parachute

722

895

28

Muffin-Mum

661

700

29

Rodney’s Aviation Ramblings

646

710

30

TVHE

640

701

31

Pdubyah – a life just as ordinary

580

739

32

Hot Topic

533

578

33

A communist at large

497

569

34

Off the couch

442

575

35

Home education Foundation

362

436

36

Stratford Aerodrome

338

438

37

Climate Justice Taranaki

324

370

38

Economics New Zealand

297

348

39

Vomkrieg

293

371

40

Quote Unquote

292

321

41

Kiwi Cakes

291

312

42

AmeriNZ

269

377

43

Perissodactyla

261

293

44

Sparrowhawk/Karearea

224

242

45

Tales from a Caffeinated Weka

217

222

46

Aughts and Oughtisms

191

280

47

Communication, Church, Society

181

241

48

Tauranga Blog

177

177

49

Mrs Cake

175

228

49

Fun with Allergy Kids

175

247

51

Cambridge NZ

166

192

52

Eye on the ICR

150

157

53

Social Media & the 2014 Election

137

144

54

Creative Voice#

134

202

55

New Zealand Conservative

123

127

55

Get Out Gertrude!

123

124

55

AnneKcam

123

147

58

Aotearoa: A wider perspective

110

112

59

Room 5 @ Melville Intermediate School

78

115

60

Media Sport and Other Rantings

77

84

60

Keeping Stock

77

80

62

John Macilree’s Weblog#

74

90

63

Cut your hair

71

71

64

Mountains of Our Minds#

66

79

65

Glennis’s Blog Page#

65

81

66

kiwi simplexity

63

63

66

The Catalyst

63

77

68

Save our Schools NZ

62

67

69

Anne Free Spirit

61

95

70

Put ’em all on an island

56

62

71

Undeniably Atheist

54

54

72

Exile in New zealand

53

68

73

Ideologically impure

52

68

73

Room One @ Auroa School

52

74

75

ElephaNZa

38

43

76

My thinks

35

36

77

Dad4justice

31

31

78

Glenview 9

29

37

79

Software development and stuff

28

28

80

Right Reason

27

27

81

Samuel Dennis

24

33

81

James McKerrow – Surveyor 1834-1919#

24

28

81

The Official Ebenezer Teichelmann Blog#

24

44

84

goNZo Freakpower Brains Trust

22

24

85

Family integrity

19

19

85

bread and pomegranates

19

22

87

Unity Blog

18

18

88

Quietly in the backgroud

17

17

89

Carolyn’s blog

16

19

89

Wokarella

16

19

89

Room 24, 2012

16

17

92

MartinIsti Blog

15

17

92

Taradale Blog#

15

61

94

Nelsonian’s life

14

15

95

John Macilree’s Blog

13

14

96

Look, Think, Make

12

12

97

ah! New Year’s Resolution

9

18

97

Journey to a mini me

9

9

97

University of Otago, Law Library Blog

9

19

100

Socialist Aotearoa

8

8

100

SmallTorque

8

9

100

Warrington Taylor#

8

11

103

Helen Heath

7

7

103

Chris Jillet – Mountaineer#

7

7

105

The Well read Kitty

6

6

105

Bob McKerrow – Wayfarer

6

6

105

kiwiincanberra

6

6

108

Utopia – you are standing in it

5

5

109

New Zealand Indian Fine Arts Society

4

4

109

sticK

4

4

109

The Little Waaagh! That Could

4

4

112

Sharlene says

3

3

113

Episto

2

2

113

Wellington Chic

2

2

113

Einstein Music Journal

2

3

116

New Zealand female Firefighter calendar

1

1

116

High voltage learning during the Christchurch earthquakes

1

1

June ’21 – NZ blogs sitemeter ranking

I notice a few regulars no longer allow public access to the site counters. This may happen accidentally when the blog format is altered. If your blog is unexpectedly missing or the numbers seem very low please check this out. After correcting send me the URL for your site meter and I can correct the information in the database.

Similarly, if your blog data in this list seems out of whack, please check your site meter. Usually, the problem is that for some reason your site meter is no longer working.

Sitemeter is no longer working so the total number of NZ blogs in this list has been drastically reduced. I recommend anyone with Sitemeter consider transferring to one of the other meters. See  NZ Blog Rankings FAQ.

This list is compiled automatically from the data in the various site meters used. If you feel the data in this list is wrong could you check to make sure the problem is not with your own site meter? I am of course happy to correct any mistakes that occur in the automatic transfer of data to this list but cannot be responsible for the site meters themselves. They do play up.

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters. Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for June 2021. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers. Meanwhile, I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings Subscribe to NZ blog rankings by Email Find out how to get Subscription & email updates

Rank Blog Visits/month Page Views/month
1 The Daily Blog 90174 370305
2 13th Floor 24319 28107
3 Liturgy 16540 20492
4 SciBlogs 14209 23310
5 Tikorangi: The Jury Garden 11009 12385
6 Bill Bennett 9633 10618
7 Homepaddock 7336 8010
8 Creative Maths 6686 7951
9 Cycling in Christchurch 5557 6451
10 Free range statistics 5456 7659
11 Music of sound 3811 4713
12 Offsetting behaviour 3576 4155
13 Lost in silver fern 3376 5177
14 Jontynz 2899 3513
15 Woodleigh Nursery 2649 4602
16 The Meaning of Trees 2151 3372
17 Nom Nom Panda 2028 2160
18 Fields of Blood 1551 1665
19 Talking Auckland 1246 1402
20 Open Parachute 1176 1446
21 The Global Couple 1169 1297
22 Anglican down under 1143 1343
23 Sarah the Gardener 1132 1451
24 Reading the maps 1029 1600
25 The Woolshed Wargamer 960 1585
26 TVHE 933 1122
27 No Minister 885 969
28 A communist at large 834 978
29 Muffin-Mum 695 737
30 Hot Topic 633 702
31 Rodney’s Aviation Ramblings 577 628
32 Off the couch 560 648
33 Pdubyah – a life just as ordinary 525 561
34 Aotearoa: A wider perspective 524 527
35 Keeping Stock 475 475
36 Home education Foundation 438 499
37 Vomkrieg 391 486
38 Quote Unquote 381 421
39 AmeriNZ 332 507
40 Aughts and Oughtisms 304 490
41 Stratford Aerodrome 301 379
42 Fun with Allergy Kids 298 383
43 Kiwi Cakes 294 335
44 Economics New Zealand 260 322
45 Tales from a Caffeinated Weka 246 249
46 Communication, Church, Society 240 300
47 Climate Justice Taranaki 231 317
48 Mrs Cake 218 294
49 New Zealand Conservative 211 214
50 Tauranga Blog 193 196
51 Perissodactyla 192 210
52 Cambridge NZ 186 256
53 Creative Voice# 169 352
54 Sparrowhawk/Karearea 161 186
55 Media Sport and Other Rantings 160 164
56 Anne Free Spirit 141 269
57 AnneKcam 131 187
58 Undeniably Atheist 129 131
58 Social Media & the 2014 Election 129 135
60 Room 5 @ Melville Intermediate School 100 122
61 Room One @ Auroa School 94 118
62 Eye on the ICR 87 96
63 Mountains of Our Minds# 85 122
64 Ideologically impure 83 100
65 goNZo Freakpower Brains Trust 79 80
66 Save our Schools NZ 78 86
67 Dad4justice 73 79
68 Glennis’s Blog Page# 71 108
69 The Catalyst 67 100
70 kiwi simplexity 64 65
70 My thinks 64 65
72 Get Out Gertrude! 59 60
73 John Macilree’s Weblog# 58 62
74 Right Reason 47 47
75 Cut your hair 46 49
76 Samuel Dennis 45 46
77 Put ’em all on an island 43 47
78 Nelsonian’s life 42 48
79 Socialist Aotearoa 41 41
80 sticK 40 40
80 ElephaNZa 40 46
82 Unity Blog 38 38
83 Exile in New zealand 34 37
84 Family integrity 33 33
85 Wokarella 32 40
86 Glenview 9 29 30
87 Software development and stuff 27 31
87 James McKerrow – Surveyor 1834-1919# 27 28
89 Bob McKerrow – Wayfarer 22 22
89 Room 24, 2012 22 22
91 MartinIsti Blog 21 22
92 Quietly in the backgroud 20 21
92 The Official Ebenezer Teichelmann Blog# 20 20
94 Journey to a mini me 19 20
94 bread and pomegranates 19 39
96 Sacraparental 14 15
96 Chris Jillet – Mountaineer# 14 14
98 John Macilree’s Blog 13 13
98 Wellington Chic 13 13
100 University of Otago, Law Library Blog 12 12
100 Look, Think, Make 12 12
102 Episto 11 11
102 Taradale Blog# 11 11
104 ah! New Year’s Resolution 10 10
105 Four seasons in one 9 9
106 The Well read Kitty 8 8
106 MandM 8 8
108 SmallTorque 7 11
109 Warrington Taylor# 6 6
110 New Zealand Indian Fine Arts Society 5 5
110 kiwiincanberra 5 5
112 New Zealand female Firefighter calendar 4 4
112 Utopia – you are standing in it 4 4
114 Helen Heath 3 3
114 Politicalisation 3 3
116 Carolyn’s blog 2 2
116 Einstein Music Journal 2 3
118 Earth is my favourite planet 1 1
118 High voltage learning during the Christchurch earthquakes 1 1
118 The Little Waaagh! That Could 1 1
118 Sharlene says 1 1

Anti-fluoridation group tells porkies about NZ fluoridation review

FFNZ spreads misinformation about the NZ fluoridation review – yet again

New Zealand opponents of community water fluoridation (CWF) are at it again. Their only response to the recently upgraded fluoridation review is to call it “propaganda” and to completely misrepresent it. But it’s interesting to look at their misrepresentation because it does highlight a basic flaw in the studies the anti-fluoride campaign has been promoting.

Fluoride Free NZ (FFNZ) claim in their recent press release (Chief Science Advisor Appears To Deliberately Mislead On Fluoride Science):

“among the many mistakes and reliance on out-of-date science, the most glaring issue is that she refers to two of the best studies ever carried out on fluoride and IQ (Mexico and Canada) as “having high prenatal exposure”. This is probably the most egregious misrepresentation in the review and hard to believe it was not done to purposely misrepresent.”

But this is completely false. In discussing the Canadian study the review actually says it:

“found that the mother’s exposure to fluoride during pregnancy was associated with lower IQ scores [54] in boys (but not girls), even at optimally fluoridated water levels (i.e. between 0.7-1.2 mg/L). If this finding were replicated in robust studies, it would potentially be concerning as Aotearoa New Zealand recommends fluoridation of water between 0.7 and 1.0 mg/L. There was significant and valid criticism of aspects of the study by many subject-matter experts when it was released (see for example, ‘expert reaction to study looking at maternal exposure to fluoride and IQ in children’). The study used sub-group analysis to find an association that is not explained in the paper (i.e. why were only boys affected [55] and why verbal IQ was not impacted), the effect appeared to be driven by the minority of participants that had much higher fluoride exposures (i.e. higher than those in Aotearoa New Zealand).” [My emphasis]

So the review does refer to the Canadian study being conducted at “optimally fluoridated water levels (i.e. between 0.7-1.2 mg/L)” – not at the elevated levels leading to “high prenatal exposure” that FFNZ falsely (and “egregiously”) asserts. But the key assertion by the NZ fluoridation review is that “the effect appeared to be driven by the minority of participants that had much higher fluoride exposures.”

Outliers lead to false conclusions

Canadian study promoted by opponents of community water fluoridation relies on just a few outliers  Image credit: The problem with outliers

It’s quite simple really. Even within a group exposed to levels of fluoride expected with CWF there can be some individuals who receive higher exposes (f0r instance through consumption of fluoridated toothpaste or industrial pollution).

Looking at the data in the Canadian study in the image below taken from Green et al (2019) we can see that while most data points are clustered together at urinary F concentrations less than 1 mg/L there are a few data points at high urinary F concentrations and these do appear to drive the relationship they report – particularly for boys.

For the more statistically inclined reader, the table below summarises the relationships obtained by linear regression analysis. While the authors reported a statistically significant relationship for all the urinary fluoride concentrations up to 2.5 mg/L when the four high-end outliers (> 2.0 mg/L) are removed there is no significant relationship.

So I think the suggestion of the updated NZ fluoridation review is quite correct. The effect reported by Green et al (2019) is driven by just a few outliers and there is no statistically significant relationship when those four outliers are removed. That gives a false impression of the effect of CWF and in fact, their data shows absolutely no difference between IQ in fluoridated areas and unfluoridated areas.

Note 1: There is a discrepancy in the first table between the relationship reported by Green et al (2019) and that based on digitally extracted data points. Unfortunately, only 82% of the claimed data points could be extracted which is strange as usually close to 100% of data points can be extracted. Other commenters have reported the same problem. So it appears the authors have not included all their data in the figures and they have so far refused to make their data available for independent statistical analysis.

Although the Green et al (2019) paper did not cite R-squared values in her Master thesis did cite an R-squared value of 0.049 for boys. The low R-squared values (meaning the inclusion of the coefficient explains at most only a few per cent of the variation) and relatively high regression standard errors suggest that the reported coefficients are meaningless (they can be ignored in any model) – even if statistically significant.

Note 2: In case anyone suggests I have neglected the FFNZ reference to the Mexican study. That study took place in an area of endemic fluorosis and the authors have no record of the water fluoride levels mothers were exposed to. Bashesh et al (2017) reported:

“By virtue of living in Mexico, individuals participating in the study have been exposed to fluoridated salt (at 250 ppm) and to varying degrees of naturally occurring fluoride in drinking water. Previous reports, based on samples taken from different urban and rural areas, indicate that natural water fluoride levels in Mexico City may range from 0.15 to 1:38 mg/L. Mean fluoride content for Mexico  City’s water supply is not available because fluoride is not reported as part of water quality control programs in Mexico.

Despite this, the Bashash study is often unjustly included with studies from areas of CWF by coauthors of Bashash and Green (see for example Farmus et al 2001). Anti-fluoride activists almost always make this mistake. Sure, they may attempt to justify their treatment of Bashash et al (2017) as relevant to CWF based on urinary fluoride values. But these a subject to so much variation and usually involve different collection and correction methods making comparison unjustified.

Similar articles

Opponents of fluoridation all at sea with new legislation

Opponents of community water fluoridation (CWF) should be supporting the proposed fluoridation legislation instead of organising opposition to it.

Think about it.

If Fluoride Free NZ (FFNZ) was honest in its claim that they are “New Zealand’s leading advocate for science in the fluoridation debate” (see their press release  Open letter to Hon Andrew little, Minister of Health) then they should be supporting science rather than ideology and insist on the best scientific scrutiny of information relating to fluoridation.

If they honestly accept the claims of those cherry-picked anti-fluoride scientists they are quoting in their social media memes then they should welcome the opportunity to expose the research of those scientists to a proper critical review.

With scientific backers like this, opponents of community water fluoridation should be welcoming the new fluoridation legislation (example of social media memes promoted by the Fluoride Action Network)

And they should welcome the proposal that the proper place for such a scientific review is the office of the Director-general of health which can call on the best scientists for information and review of the evidence. That proposal is an integral part of the draft legislation which requires that the Director-General must consider the scientific evidence related to community water fluoridation before making a direction that CWF be introduced or stopped in a region (see clause 116E : Director-General may direct local authority to add or not to add fluoride to drinking water in the Supplementary Order Paper).

So, it appears strange that instead of welcoming the new legislation FFNZ is mobilising their supporters to oppose it. And their US colleagues at the Fluoridation Action Network are pouring their resources into the FFNZ campaign.

But why? It is ridiculous for pro-science people to campaign to retain the old system where the evaluation of evidence and decisions on CWF were made by scientific and political naive councillors in local bodies. Councillors who could be easily captured by activists and fooled by their misrepresentation of the science., Councillors who are more concerned with their next election or chances of claiming the Mayor’s job than any science. And councillors who are already predisposed to the claims of the activists, who may indeed be activists themselves, who were more concerned with ideological orientation than any science.

If the fluoridation opponents organised by FFNZ are really “leading advocates for science” and want recent research they are promoting to be considered in fluoridation decisions then they would be supporting the new legislation rather than opposing it.

Ideological distortion of science

I really wonder at a group of ideologically motivated people making submissions promoting their understanding (or misunderstanding) of the science to the Parliamentary Health Committee when that committee is simply not tasked with considering the science. Its job is to consider proposals for the reorganisation of the mechanism for making fluoridation decisions – nothing to do with science itself.

Instead of wasting their submissions on this bill, they should be saving them for promotion of their beliefs about what the science claims to the Director-General of Health and his/her staff. Once this bill is passed the Director-General of Health’s office should be a great place for these claims to be properly considered and reviewed.

That would be a vast improvement on the old situation when they took their arguments to scientifically and politically naive local body councils. Or brought in US anti-fluoridation spokesmen to speak to audiences of homoeopaths, head massagers and other alternative health advocates and their followers.

Or perhaps I am the naive one. Perhaps fluoridation opponents prefer to make their arguments to those local body councillors instead of scientifically capable people. Perhaps FFNZ is dishonest to claim they are ““New Zealand’s leading advocate for science in the fluoridation debate.” 

Similar articles

 

Update of NZ fluoridation review timely and useful

Image credit: Kurt:S/Flickr (CC BY-SA 2.0).

An updated New Zealand scientific review of community water fluoridation (CWF) finds that CWF in New Zealand is safe and effective. The new review, Fluoridation: an update on evidence, was published by the New Zealand Prime Minister’s Chief Science Advisor Juliet Gerrard FRSNZ HonFRSC. It examines scientific findings published since the last New Zealand fluoridation review in 2014 – Eason et al (2014). Health effects of water fluoridation: A review of the scientific evidence. It states:

“Royal Society Te Apārangi published a comprehensive review in 2014 looking at the health effects of water fluoridation [Eason et al. 2014]. The review found that there were no adverse effects of fluoride of any significance arising from fluoridation at the levels used in Aotearoa New Zealand. We have considered new research on fluoridation and comprehensive reviews published subsequently, and find that the conclusions of the Royal Society Te Apārangi remain appropriate.”

So, in effect, nothing new there as far as conclusions are concerned. New Zealanders should continue to welcome CWF without any fear of negative effects. But some readers may be interested in the details – specifically the review’s conclusions about the new research which anti-fluoride activists have been promoting of late. Opponents of CWF have in the last year or so almost exclusively concentrated their campaigns on claimed harmful neurodevelopmental and cognitive impacts. The review considers this in a section “Could fluoride have possible neurodevelopmental and cognitive health effects?” and concludes:

“Recent studies continue to show that at very high levels and with chronic exposure, fluoride could potentially have negative neurodevelopmental and cognitive impacts. However, this is not a concern at levels used in fluoridation of water supplies in Aotearoa New Zealand.”

In particular, the new review considered the studies opponents of CWF claim show harmful effects at the water fluoride concentrations used in CWF. It found problems with these studies and states:

“The conclusion reached by Royal Society Te Apārangi remains appropriate. While there is some evidence that high fluoride concentrations may have an adverse effect on developing brains, there is no convincing evidence of neurological effects at fluoride concentrations achieved by fluoridation of water supplies in Aotearoa New Zealand.”

The new review could be better

Of course, the review is written for policymakers and politicians who want the conclusions but don’t want to see the detailed evidence. They will have confidence that behind the scenes proper scientific scrutiny was made of the studies discussed. But, as a scientist, I would have liked to see more details about that scrutiny. For example, a lot more could be said about the deficiencies of the Canadian study (Green et al., 2019) than:

“There was significant and valid criticism of aspects of the study by many subject-matter experts when it was released (see for example, ‘expert reaction to study looking at maternal exposure to fluoride and IQ in children’). The study used sub-group analysis to find an association that is not explained in the paper (i.e. why were only boys affected and why verbal IQ was not impacted), the effect appeared to be driven by the minority of participants that had much higher fluoride exposures (i.e. higher than those in Aotearoa New Zealand).”

I find this statement in the review a bit misleading:

“The results found in the study undertaken in Canada [56] are also in contrast to those found in the study undertaken in Aotearoa New Zealand [57], which has the advantage of more accurately reflecting local contextual factors.”

It refers to the Green et al., (2019) and Broadbent et al (2015) studies claiming their results are contradictory. But in terms of their comparison of IQ in fluoridated and unfluoridated areas this table shows their findings were exactly the same – absolutely no difference. (Till et al 2020 used essentially the same Canadian data) I think this comparison should have been made clear in the review because it is important but is most often overlooked because opponents of fluoridation, and the study’s authors,  never consider it. They remain silent about the facts in this table. This is hypocritical considering the attempts anti-fluoridation critics made to discredit the same finding reported by Broadbent et al (2015) when their paper was published.

Fluoridation opponents have instead concentrated on the relationships between maternal urinary fluoride and child IQ outcomes reported by Green et al (2019). However, all those relationships were extremely weak (explaining only a few per cent of the variation) or statistically non-significant.

The bias of the authors of the Green et al (2019) and Till et al (2020) studies is evident not only in their complete absence of discussion of their own results showing no difference between fluoridated and unfluoridated areas. It is also shown by the fact neither Green et al (2019) or Till et al (2020) referred to the findings of Broadbent et al (2015) or include that paper in their discussion or reference list. (Contrast this with the fact Green et al 2019 included four papers published in the journal Fluoride, known for its anti-fluoridation bias and poor quality).

These omissions are serious as Broadbent et al (2015) is the only other study of IQ in areas including CWF. This defect in the papers appears not to have been picked up by the publishing journals’ referees – which brings me to question the quality of the peer review used for these papers.

We really need to have a more extensive critique of these studies with proper consideration of the methodologies used (e.g. measurement of urinary fluoride and cognitive factors), the statistical relevance of the reported relationships and the quality of their literature reviews and discussions.

A timely, authoritative and useful review

This new review is timely. The NZ Parliament will soon pass legislation removing the current local body control of regional fluoridation decisions over to the Director-General of Health. Anti-fluoride activists will actively campaign against this and will be promoting misinformation about the recent research. The new review provides lawmakers and the media with up to date scientific information, presented in a popular format, which will counter the anti-fluoridation campaigners.

The backing of the office of the New Zealand Prime Minister’s Chief Science Advisor provides scientific authority. As do the 12 reputable scientists who provided peer reviews of the document.

The more science-savvy members of the public who want to see evidence rather than simply rely on recommendations will also find the review and its bibliography useful.

At this stage, it is not clear how anti-fluoride organisations will attempt to discredit the new review and its findings. In 2014 they worked hard to discredit the NZ Fluoridation Review prepared by the Royal Society of New Zealand and the Office of the Prime Minister’s Chief Science Advisor (Health effects of water fluoridation: A review of the scientific evidence.) They prepared their own critique (promoted as a critique by “international scientists “but actually written by, and “peer-reviewed” by, the usual small group of anti-fluoride scientists and activists) –  with their report Scientific and Critical Analysis of the 2014 New Zealand Fluoridation Report. I critiqued and analysed the report in NZ Community Water Fluoridation is Safe and Effective: A critique of Fluoride Free NZ’s criticisms of the NZ Fluoridation Review which can be downloaded as a pdf.

Many opponents of CWF may be distracted by other things like the Covid19 vaccination issue at the moment. However, the anti-fluoridation campaign has big financial backers locally and internationally so it is likely they will come up with something a lot more effective than the recent attempt by Fluoride Free NZ to pretend that the new review effectively supports their claims.

I look forward to analysing any substantial critique they can make of the updated NMZ Fluoridation review.

A meme promoted by Fluoride Free NZ seeks to pretend the new fluoridation review supports their claims. It doesn’t.

Similar articles

May ’21 – NZ blogs sitemeter ranking

I notice a few regulars no longer allow public access to the site counters. This may happen accidentally when the blog format is altered. If your blog is unexpectedly missing or the numbers seem very low please check this out. After correcting send me the URL for your site meter and I can correct the information in the database.

Similarly, if your blog data in this list seems out of whack, please check your site meter. Usually, the problem is that for some reason your site meter is no longer working.

Sitemeter is no longer working so the total number of NZ blogs in this list has been drastically reduced. I recommend anyone with Sitemeter consider transferring to one of the other meters. See  NZ Blog Rankings FAQ.

This list is compiled automatically from the data in the various site meters used. If you feel the data in this list is wrong could you check to make sure the problem is not with your own site meter? I am of course happy to correct any mistakes that occur in the automatic transfer of data to this list but cannot be responsible for the site meters themselves. They do play up.

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters. Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for May 2021. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers. Meanwhile, I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings Subscribe to NZ blog rankings by Email Find out how to get Subscription & email updates

Rank Blog Visits/month Page Views/month

1

The Daily Blog

70934

315974

2

Liturgy

22578

28401

3

13th Floor

21991

25681

4

Tikorangi: The Jury Garden

15334

17081

5

SciBlogs

12706

22756

6

Bill Bennett

10239

10996

7

Creative Maths

7791

9283

8

Homepaddock

7344

8001

9

Sacraparental

6953

8017

10

Free range statistics

6719

9426

11

Cycling in Christchurch

6381

7319

12

Music of sound

4245

5492

13

Lost in silver fern

4216

6325

14

Offsetting behaviour

3408

3963

15

Nom Nom Panda

3118

3330

16

Woodleigh Nursery

3116

5100

17

Jontynz

2267

2761

18

The Meaning of Trees

2151

3372

19

No Minister

1526

1757

20

Fields of Blood

1481

1702

21

Sarah the Gardener

1364

1769

22

Talking Auckland

1356

1579

23

Anglican down under

1304

1589

24

The Global Couple

1182

1327

25

Reading the maps

1134

1542

26

The Woolshed Wargamer

1072

1801

27

Open Parachute

964

1164

28

A communist at large

924

1135

29

Muffin-Mum

917

992

30

TVHE

779

870

31

Hot Topic

692

781

32

Rodney’s Aviation Ramblings

669

785

33

Economics New Zealand

554

609

34

Pdubyah – a life just as ordinary

521

568

35

Off the couch

472

575

36

Fun with Allergy Kids

420

561

37

Vomkrieg

390

510

38

Home education Foundation

389

476

39

Aughts and Oughtisms

363

520

40

Kiwi Cakes

352

390

41

Quote Unquote

319

356

42

AmeriNZ

296

547

43

Tales from a Caffeinated Weka

292

305

44

Stratford Aerodrome

285

345

45

Communication, Church, Society

262

412

46

Climate Justice Taranaki

253

369

47

Perissodactyla

233

283

48

Mrs Cake

205

273

49

Sparrowhawk/Karearea

199

266

50

New Zealand Conservative

193

197

51

Cambridge NZ

189

213

52

Creative Voice#

185

342

53

Social Media & the 2014 Election

154

180

54

Eye on the ICR

150

154

55

Save our Schools NZ

148

159

56

Tauranga Blog

143

167

56

AnneKcam

143

187

58

Media Sport and Other Rantings

141

141

59

My thinks

133

167

60

Anne Free Spirit

127

193

61

The Catalyst

111

144

62

Mountains of Our Minds#

100

133

63

goNZo Freakpower Brains Trust

98

99

64

Room 5 @ Melville Intermediate School

95

119

65

Room One @ Auroa School

87

129

66

Right Reason

83

83

67

Aotearoa: A wider perspective

79

82

67

Undeniably Atheist

79

82

69

Glennis’s Blog Page#

78

107

70

Ideologically impure

63

73

71

Put ’em all on an island

61

68

72

John Macilree’s Weblog#

49

53

73

Get Out Gertrude!

48

175

74

Unity Blog

44

55

75

Exile in New zealand

39

40

75

Quietly in the backgroud

39

44

77

Samuel Dennis

38

42

78

Nelsonian’s life

35

40

79

Wellington Chic

33

33

80

Wokarella

32

38

81

MartinIsti Blog

30

31

82

bread and pomegranates

27

34

83

Dad4justice

25

28

83

Family integrity

25

25

83

James McKerrow – Surveyor 1834-1919#

25

26

86

Keeping Stock

23

23

87

ElephaNZa

20

23

88

Glenview 9

18

24

89

Software development and stuff

16

17

89

University of Otago, Law Library Blog

16

19

91

kiwiincanberra

15

15

91

Cut your hair

15

17

93

Journey to a mini me

14

14

94

Room 24, 2012

13

13

94

The Official Ebenezer Teichelmann Blog#

13

20

96

John Macilree’s Blog

12

14

96

Look, Think, Make

12

12

98

kiwi simplexity

11

13

98

Chris Jillet – Mountaineer#

11

14

100

The Well read Kitty

10

10

100

New Zealand female Firefighter calendar

10

10

102

MandM

9

9

102

Four seasons in one

9

9

102

Taradale Blog#

9

10

105

Carolyn’s blog

8

10

105

Warrington Taylor#

8

8

107

ah! New Year’s Resolution

7

7

107

SmallTorque

7

11

109

Utopia – you are standing in it

5

5

110

Helen Heath

4

4

111

New Zealand Indian Fine Arts Society

3

5

111

Socialist Aotearoa

3

3

113

In the back of the net

1

1

113

High voltage learning during the Christchurch earthquakes

1

1

113

The Little Waaagh! That Could

1

1

113

Einstein Music Journal

1

1

Fluoridation contribution to heavy metals in drinking water is too low to measure

Anti-fluoride activists claims of fluoridation chemicals being laced with toxic metals just do not stand up to scrutiny

Anti-fluoridation activists claim fluoridation adds toxic heavy metals to drinking water because the fluoridation chemicals are “waste products” from industry (the phosphate fertiliser industry). Despite the fact that published research shows this not true.

The activists rarely give evidence for their claims but when they do they cite chemical data from certificates of compliance supplied to local bodies by the fluoridation chemical providers. But these activists simply have no concept of what these figures mean and always ignore the huge dilution involved in water treatment.

Example of continually tweeted scaremongering misinformation from the Fluoride Action Network’s press officer.

Anti-fluoride people particularly go on about arsenic yet a 2015 Canadian study showed that the difference in arsenic levels from unfluoridated and fluoridated water treatment plants was infinitesimal. That study is:

Peterson, E., Shapiro, H., Li, Y., Minnery, J. G., & Copes, R. (2015). Arsenic from community water fluoridation: quantifying the effect. Journal of Water and Health.

The data shows that even after treatment the concentration of arsenic due to natural sources is about 0.44 ppb. Fluoridation added a mere 0.07 ppb to this! (ppb = parts per billion = micrograms/litre = μg/L).

See Another defeat for anti-fluoridation claims about arsenic for a discussion of this paper.

The authors point out that all the drinking water systems in their study were compliant with the Canadian drinking water guideline for arsenic of 10 μg/L (10 ppb [parts per billion] – the same as in New Zealand) and the estimated amount attributable to fluoridation from this study is less than 1% of this guideline. Their results were also consistent with other published estimates of the likely contribution of fluoridation chemicals to arsenic in drinking water.

The fluoridation chemicals used in New Zealand have lower levels of impurities than those used in North America so the resulting contamination of drinking water is even lower than in Canada.

Here I look at the heavy metals contaminants in our drinking water and the effect of fluoridation on those levels

What are the concentrations of contaminants in our tap water?

They are very low – in fact, they are regulated to be very low. The regulations set maximum allowable levels (MAV) and providers must keep their contaminant below these MAV levels.

The figure below uses data taken from reports for the Hamilton City Council Water Supply Annual Compliance Report 2018/2019. I have converted the data from units of g/m3 to parts per billion – ppb. I have used data from  a certificate of compliance for the hydrofluorosilicic acid (HFA) supplied to the Hamilton City Council in 2015 (referred to in my article Chemophobic scaremongering: Much ado about absolutely nothing)

I have made this figure tall in an attempt to show the calculated contribution of contaminants concentrations from the fluoride treatment (red) alongside the actual measured levels in the tap water (green). The Y-axis is different for Barium and Aluminium because the concentrations are much higher. Click on the image to see a larger version of the figure

Here are some relevant points about this data:

1: Lead is not included because the amount is below the detection limit. The measured levels of the other contaminants of interest (green) are very low – well below the MAV values.

Waikato River water contains relatively high levels of arsenic – higher than MAV recommendations. But water treatment reduces the levels to well below the MAV level (and in some samples the levels are below the detection limit).

2: The calculated levels for contaminants due to added fluoridation chemicals (HFA – hydrofluorosilicic acid) are extremely low. In fact, in all cases, they are well below the levels that could be detected by the analytical methods used – in most cases far less than 1% of the detectable levels.

This means that the final concentration in drinking water of heavy metals added with the fluoridation chemicals is far too low to even be detected by the sensitive chemical analytical methods used. It is simply misleading for anti-fluoride activists to rave on about the contaminant levels in the concentrated chemicals without taking into account the huge dilution involved.

3: The figure below illustrates that the fluoridation treatment makes only a minuscule (undetectable) contribution of contaminant elements to the tap water.  Well under 1% of the contaminant contribution coming from the source water itself.

Conclusion

Fluoridation chemicals add such a minuscule amount of heavy metals to drinking water that their contribution cannot be detected. The amounts are below the detection limit of the analytical methods used.

The claims of anti-fluoride activists are emotional rather than factual. It is meaningless to publish images of compliance certificates. When they cite chemical data for the fluoridation chemicals used they simply have no concept of what the figures mean and completely ignore the high dilution factor involved in treating drinking water.

Similar articles

April ’21 – NZ blogs sitemeter ranking


Image credit:
Blog Writing For Business NZ

I notice a few regulars no longer allow public access to the site counters. This may happen accidentally when the blog format is altered. If your blog is unexpectedly missing or the numbers seem very low please check this out. After correcting send me the URL for your site meter and I can correct the information in the database.

Similarly, if your blog data in this list seems out of whack, please check your site meter. Usually, the problem is that for some reason your site meter is no longer working.

Sitemeter is no longer working so the total number of NZ blogs in this list has been drastically reduced. I recommend anyone with Sitemeter consider transferring to one of the other meters. See  NZ Blog Rankings FAQ.

This list is compiled automatically from the data in the various site meters used. If you feel the data in this list is wrong could you check to make sure the problem is not with your own site meter? I am of course happy to correct any mistakes that occur in the automatic transfer of data to this list but cannot be responsible for the site meters themselves. They do play up.

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters. Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for April 2021. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers. Meanwhile, I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings Subscribe to NZ blog rankings by Email Find out how to get Subscription & email updates

Rank Blog Visits/month Page Views/month

1

The Daily Blog

62558

267659

2

Liturgy

34006

40649

3

13th Floor

21768

25129

4

Tikorangi: The Jury Garden

15043

16766

5

Sacraparental

11595

13116

6

Bill Bennett

9320

9924

7

Cycling in Christchurch

8037

9059

8

Creative Maths

7790

9130

9

SciBlogs

7520

17274

10

Homepaddock

7406

8122

11

Free range statistics

6924

9312

12

Music of sound

4531

5942

13

Lost in silver fern

4029

6089

14

Offsetting behaviour

3726

4252

15

Nom Nom Panda

3437

3702

16

Woodleigh Nursery

2575

4645

17

Jontynz

2505

2888

18

The Meaning of Trees

2151

3372

19

Talking Auckland

1411

1578

20

No Minister

1328

1574

21

The Global Couple

1267

1447

22

Fields of Blood

1202

1387

23

Anglican down under

1197

1535

24

The Woolshed Wargamer

1164

2079

25

Economics New Zealand

1143

1165

26

Open Parachute

1077

1324

27

Reading the maps

997

1278

28

A communist at large

967

1213

29

Sarah the Gardener

929

1230

30

Muffin-Mum

889

937

31

Off the couch

740

917

32

Hot Topic

677

866

33

Rodney’s Aviation Ramblings

594

749

34

TVHE

572

649

35

Pdubyah – a life just as ordinary

470

513

36

Home education Foundation

448

526

37

Vomkrieg

382

495

38

Aughts and Oughtisms

367

468

39

Stratford Aerodrome

359

498

40

Climate Justice Taranaki

346

432

41

Kiwi Cakes

325

378

42

Fun with Allergy Kids

306

425

43

AmeriNZ

301

495

44

Communication, Church, Society

277

330

45

Tales from a Caffeinated Weka

264

271

46

Quote Unquote

263

285

47

Perissodactyla

242

267

48

Cambridge NZ

241

263

49

Mrs Cake

214

271

50

Sparrowhawk/Karearea

195

239

51

New Zealand Conservative

175

195

52

Media Sport and Other Rantings

156

159

53

Creative Voice#

144

275

54

Social Media & the 2014 Election

125

150

55

The Catalyst

121

150

56

AnneKcam

112

141

57

Mountains of Our Minds#

111

152

58

Tauranga Blog

104

107

59

Save our Schools NZ

101

105

60

Eye on the ICR

100

122

61

Ideologically impure

89

111

62

Room One @ Auroa School

85

117

63

Room 5 @ Melville Intermediate School

78

92

64

Right Reason

76

76

65

Unity Blog

73

102

65

Undeniably Atheist

73

83

67

My thinks

64

68

67

Glennis’s Blog Page#

64

75

69

Aotearoa: A wider perspective

62

66

70

Exile in New zealand

60

81

71

John Macilree’s Weblog#

58

64

72

Put ’em all on an island

51

58

73

goNZo Freakpower Brains Trust

50

51

73

Anne Free Spirit

50

74

75

Quietly in the backgroud

44

47

76

Family integrity

39

39

76

Wokarella

39

56

78

Glenview 9

30

30

79

ElephaNZa

29

31

80

Wellington Chic

28

28

81

Software development and stuff

24

25

82

Keeping Stock

22

22

82

University of Otago, Law Library Blog

22

32

84

James McKerrow – Surveyor 1834-1919#

20

22

85

MartinIsti Blog

19

21

85

Nelsonian’s life

19

20

87

Dad4justice

16

16

88

John Macilree’s Blog

15

15

88

Get Out Gertrude!

15

21

88

kiwiincanberra

15

15

88

The Official Ebenezer Teichelmann Blog#

15

15

92

kiwi simplexity

14

14

93

Look, Think, Make

12

12

94

Cut your hair

11

11

94

Warrington Taylor#

11

11

96

Carolyn’s blog

10

11

96

Samuel Dennis

10

10

96

bread and pomegranates

10

17

96

Chris Jillet – Mountaineer#

10

10

100

Helen Heath

9

9

100

Four seasons in one

9

9

102

MandM

8

8

102

Journey to a mini me

8

8

104

The Well read Kitty

7

8

104

New Zealand female Firefighter calendar

7

7

104

Room 24, 2012

7

7

107

ah! New Year’s Resolution

6

6

108

Taradale Blog#

5

5

109

New Zealand Indian Fine Arts Society

4

4

109

Socialist Aotearoa

4

4

111

High voltage learning during the Christchurch earthquakes

3

3

112

SmallTorque

2

2

112

Utopia – you are standing in it

2

3

114

Bob McKerrow – Wayfarer

1

1

114

The Little Waaagh! That Could

1

1

114

Misses Mac

1

1