Daily Archives: January 31, 2015

Pro-Fluoride Advocacy Obscures Accuracy

This is a good example of a point made frequently on this blog how presuppositions drive study analyses and conclusions. The authors of this study (click here) have made very critical assumptions up front (perhaps without even realizing it). For example, it is assumed that fluoride addition to drinking water is always beneficial and it is to be the default position unless proven harmful. As a result the fictitious “antifluoridation” network (sometimes called anti’s) is a conspiracy to be resisted, is putting out “misinformation” , must be monitored for “accuracy”, and that public health agencies have to communicate better to get the profluoride message out.

What has been assumed from the beginning is the very issue in question. There is little if any basis for the presumption that fluoride addition to drinking water is never harmful and everyone should have it in their drinking water. Public health workers in many cases are profluoride because they have been told that it is good and told that those opposing it are misinformed, without ever having considered the underlying issues.

One could have just as easily looked on the internet to discover the connectedness of the “profluoride” network. Neither of these approaches help to answer the most important questions (e.g. whether fluoride should be added to drinking water at all. ) Assuming away the real issues at hand is to be blinded by assumptions.

Lastly, I’d say publication of such a “study”, which is essentially an internet search, as a “peer-reviewed” journal article reflects the advocacy of the AJPH than anything else.

Seymour B, Getman R, Saraf A, Zhang LH, Kalenderian E. When Advocacy Obscures Accuracy Online: Digital Pandemics of Public Health Misinformation Through an Antifluoride Case Study. Am J Public Health. 2015 Jan 20:e1-e7.

Objectives. In an antifluoridation case study, we explored digital pandemics and the social spread of scientifically inaccurate health information across the Web, and we considered the potential health effects.

Methods. Using the social networking site Facebook and the open source applications Netvizz and Gephi, we analyzed the connectedness of antifluoride networks as a measure of social influence, the social diffusion of information based on conversations about a sample scientific publication as a measure of spread, and the engagement and sentiment about the publication as a measure of attitudes and behaviors.

Results. Our study sample was significantly more connected than was the social networking site overall (P < .001). Social diffusion was evident; users were forced to navigate multiple pages or never reached the sample publication being discussed 60% and 12% of the time, respectively. Users had a 1 in 2 chance of encountering negative and nonempirical content about fluoride unrelated to the sample publication.

Conclusions. Network sociology may be as influential as the information content and scientific validity of a particular health topic discussed using social media. Public health must employ social strategies for improved communication management.

Quebec City Disinfection Byproducts Not Associated with Risk of “Small-for-Gestational-Age” Neonate

Ileka-Priouzeau S, Campagna C, Legay C, Deonandan R, Rodriguez MJ, Levallois P. Women exposure during pregnancy to haloacetaldehydes and haloacetonitriles in drinking water and risk of small-for-gestational-age neonate. Environmental Research. 2015 Jan 16;137C:338-348. doi: 10.1016/j.envres.2015.01.005.

BACKGROUND: Past studies have examined the effects of maternal exposure to water chlorination disinfection by-products (DBPs), such as trihalomethanes (THMs) and haloacetic acids (HAAs) during pregnancy. However, no human-based study has yet evaluated the effect of emerging DBPs, such as haloacetaldehydes (HAs) and haloacetonitriles (HANs) on small-for-gestational-age (SGA) status in newborns.

OBJECTIVE: This study aims to assess the association between maternal multiroute exposure to HAs and HANs during the third trimester of pregnancy and SGA status at birth, among neonates delivered by women residing in the Quebec City area (Province of Quebec, Canada). We also evaluated the interaction between exposure to these emerging unregulated by-products and regulated DBPs also found in drinking water (THMs and HAAs), for which a positive association with adverse reproductive outcomes has been suggested in previous studies.

METHODS: We conducted a population-based case-control study in the Quebec City area. SGA newborns (n=330) were compared to 1100 controls, with matching based on calendar week of birth. HA and HAN concentrations in drinking water at participant’s tap were estimated using spatio-temporal strategy based on bimonthly measurements carried out at several locations in the participant’s distribution system. A computer-assisted telephone interview was completed to collect information on individual habits of water consumption and water related activities in order to determine individual multiroute exposure. This enabled us to estimate the dose of HAs and HANs absorbed daily by each participant. Associations between total HA, HAN concentrations in drinking water and SGA were analyzed. Associations between the daily-absorbed doses of these emerging DBPs and SGA were also analyzed. Odds ratios (ORs) comparing the 4th quartile of exposure to the reference group (the first three quartiles) were obtained by means of conditional logistic regression, and controlling for potential confounders.

RESULTS: Globally, no evidence of increased risk of SGA was found with total HA and HAN concentrations in tap water when participants in the 4th quartile of exposure were compared to the first three quartiles (OR=1.0; 95% CI [0.7-1.5] and OR=0.8; 95% CI [0.6-1.2], respectively). Similarly, no association was found with the daily-absorbed doses of total HAs or HANs (OR=0.9; 95% CI [0.6-1.3] and OR=1.1; 95% CI [0.7-1.6], respectively). However, a small non statistically significant association was found between the dose of brominated HA and SGA (OR=1.4; 95% CI [0.9-2.1]). Also, in spite of the lack of interaction between other DBP classes, an unexpected negative interaction was observed between concentration of chloral hydrate (CH) (which represents the main HA species), and regulated DBPs (P=0.006).

CONCLUSION: In this population, exposure to low levels of HAs and HANs during the third trimester of pregnancy through drinking water was not associated to SGA status in newborns. Nonetheless, more research is needed to clarify possible effect of brominated compounds and interaction between different DBPs.

Click here for paper (fee).