Daily Archives: January 12, 2012

Zhou et al 2012: Decreased birth weight in relation to maternal urinary trichloroacetic acid levels

Drawing conclusions based on the regression┬ádata provided in this paper is a stretch given the spread….

Zhou, W.S., L. Wu, S.H. Xie, Y.L. Li, L. Li, Q. Zeng, Y.K. Du, and W.Q. Lu. Decreased birth weight in relation to maternal urinary trichloroacetic acid levels. Sci Total Environ. 2012 Jan 4. http://dx.doi.org/10.1016/j.scitotenv.2011.10.073

BACKGROUND: The effect of exposure to disinfection by-products (DBPs) during pregnancy on newborn’s birth weight has been commonly described in animal studies. However, epidemiological evidence was not consistent.

OBJECTIVES: To investigate the relationship between exposure to DBPs and newborn’s birth weight in a Chinese population, we conducted a cross-sectional study in Wuhan, China.

METHODS: A total number of 398 women who had given birth to a live singleton with a gestational age between 37 to 42weeks were recruited from a local hospital between November 2008 and May 2009. Basic information for all mothers and newborns was obtained from clinic birth records. Among these subjects, 180 women also gave further information including maternal medical history, social status and water-use behaviors by a face-to-face interview. Urinary creatinine (Cr) adjusted trichloroacetic (TCAA) was used as an exposure biomarker.

RESULTS: No statically significant results were found in the linear regression for both 398 participants and 180 participants who finished questionnaires. However, both the crude and adjusted results showed that the mean birth weight of the subjects in the third and top quartiles of Cr-adjusted urinary TCAA concentrations was decreased compared with those in the lowest quartile. Subjects in the top quartiles had the lowest mean birth weight compared to those in other quartiles. In addition, a weak correlation was observed among 82 subjects between drinking water ingestion and urinary Cr-adjusted TCAA (r=0.23, P=0.04).

CONCLUSION: Our findings suggested that elevated exposure to DBPs may affect fetal growth. The effect of exposure to DBPs during pregnancy on birth weight still warrants further investigations.

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Congressional Letter: Tier 3 standards for gasoline

Frazao et al: Drinking water quality and fluoride concentration

Frazao, P., M.A. Peres, and J.A. Cury. Drinking water quality and fluoride concentration. Rev Saude Publica. 2011 Oct;45(5):964-73. Epub 2011 Jul 22.

This paper aimed to analyze the fluoride concentration in drinking water, taking into account the balance between the benefits and risks to health, in order to produce scientific backing for the updating of the Brazilian legislation. Systematic reviews studies, official documents and meteorological data were examined. The temperatures in Brazilian state capitals indicate that fluoride levels should be between 0.6 and 0.9 mg F/l in order to prevent dental caries. Natural fluoride concentration of 1.5 mg F/l is tolerated for consumption in Brazil if there is no technology with an acceptable cost-benefit ratio for adjusting/removing the excess. Daily intake of water with a fluoride concentration > 0.9 mg F/l presents a risk to the dentition among children under the age of eight years, and consumers should be explicitly informed of this risk. In view of the expansion of the Brazilian water fluoridation program to regions with a typically tropical climate, Ordinance 635/75 relating to fluoride added to the public water supply should be revised.

Click here for full paper (free).