Daily Archives: August 9, 2011

Drinking Water Violations Get Press Attention

Regardless of what a drinking water regulation requires for public notification, water systems that violate a standard will be better off letting their customers know sooner rather than later. Consider this example from Tennessee (click here).

Knox et al 2011: Perfluorocarbon exposure, gender and thyroid function in the C8 Health Project.

This study is one of many that examines data from the C8 Health Project. This paper assessed thyroid function in a cross-sectional analysis of 52,296 adults with a year or more of exposure to perfluorooctanoate (PFOA) from drinking water.

The major conclusion presented by the authors is below:

“Our primary finding was that of significant gender differences in thyroxine and T3 uptake associated with exposure to PFOS and PFOA which have not previously been reported in the literature. The increase of total thyroxine and reduction of T3 uptake associated with perfluorocarbons in both men and women is most consistent with an increase in the production of TBG. Unfortunately, this could not be verified because TBG was not measured. The only thyroid hormone binding protein actually available for analysis was albumin, which only binds a small amount of thyroxine. Nevertheless, there were positive associations between albumin and both PFOA and PFOS in both genders and age groups. This is only suggestive because albumin is a non-specific protein binding globulin. Mechanistically, the associations of perfluorocarbons with total thyroxine and T3 uptake are consistent with a hepatic increase in production of TBG without significant influence from the hypothalamic pituitary thyroid axis. This is supported by the fact that there is no increase in thyroid stimulating hormone TSH associated with increases in PFOA of PFOS. The pattern found in these data is consistent with what occurs with the use of exogenous estrogens in patients, namely an increase in TBG by not TSH (Tahboub and Arafah, 2009; Sanger et al., 2008), an increase in total thyroxine and a decrease in T3 uptake.”

 Knox, S., T. Jackson, S. Frisbee, B. Javins, A. Ducatman. 2011.  Perfluorocarbon exposure, gender and thyroid function in the C8 Health Project. J Toxicol Sci. 2011;36(4):403-10.

West Virginia University School of Medicine, Department of Community Medicine.

Click here for the abstract (also below) and full paper (open source).

Abstract

Perfluorocarbons from common household products such as food containers, stain- resistant protection for clothing, furniture and carpets, paints, and fire-fighting foams are found in soil, water, plants, animal and human serum worldwide. Previous research has shown a significant association between these chemicals and thyroid disease in women. The present data from the C8 Health Project assessed thyroid function in a cross-sectional analysis of 52,296 adults with a year or more of exposure to perfluorooctanoate (PFOA) from drinking water. Outcomes were: thyroxine, T3 uptake, and thyroid stimulating hormone (TSH). Analyses were stratified by gender and age group (< 20 – < 50 years and > 50). Both PFOA and perfluorooctane sulfonate (PFOS) were associated with significant elevations in serum thyroxine and a significant reduction in T3 uptake in all participants. There were also significant gender/PFOS interactions for T3( )uptake and thyroxine, as well as gender/PFOA interactions for T3 uptake. Results provide evidence for disruption of thyroid function related to these common chemicals and possible mechanisms are discussed.

Canu et al 2011: Health Effects of Naturally Radioactive Water Ingestion: The Need for Enhanced Studies

This study examines the available epidemiological findings concerning the health effects of naturally radioactive water ingestion. The authors conclude: 

“Despite modest human epidemiological evidence of uranium nephrotoxicity and radium bone carcinogenicity, available studies do not clearly demonstrate health effects of radionuclides at levels naturally encountered in drinking-water. Methodological limitations (exposure assessment, possible confounders, limited sample size), affecting most reviewed studies, should be remedied in future studies.”

Click here for the abstract (and below) and for the full paper (open source).

Canu, I.G., O. Laurent, N. Pires, D. Laurier, and I. Dublineau. 2011. Health Effects of Naturally Radioactive Water Ingestion: The Need for Enhanced Studies.  Environmental Health Perspectives. http://dx.doi.org/10.1289/ehp.1003224

Abstract

BACKGROUND: Radiological pollution is a potentially important aspect of water quality. Yet, relatively few studies have been conducted to document its possible health effects.

OBJECTIVE: In this paper we comment on the available epidemiological findings, but also on related data from experimental studies, concerning the health effects of naturally radioactive water ingestion.

DISCUSSION: Despite modest epidemiological evidence of uranium nephrotoxicity and radium effects on bone, available data are not sufficient to quantify the health effects of naturally occurring radionuclides in water. Methodological limitations (exposure measurement methods, control for confounding, sample size) affect most studies. Power calculations should be conducted before launching new epidemiological studies focusing on late pathological outcomes. Studies based on biomarkers of exposure and adverse effects may be helpful but should involve more specific molecules than biomarkers used in previous studies. Experimental data on ingestion of drinking-water are limited to uranium studies, and there is some disagreement between these studies about the nephrotoxicity threshold.

CONCLUSION: Further experimental and enhanced epidemiological studies should help to reduce uncertainties, from dose estimation to dose-response characterisation.

 

Warning System for Detecting Distributed Water Quality Changes

A new security product is being tested that measures changes in refractive index to detect changes in water quality. Click here for more info.