Daily Archives: April 24, 2015

Arsenic Effects and Myelomeningocele (Neural Tube Defects)

As with most studies of this type the primary weakness (if not fatal flaw) is in the exposure assessments. Exposure to arsenic was not measured. More importantly, if the women were exposed to arsenic the next question should be “What other contaminants were also present in the water?”

Mazumdar M, Ibne Hasan MO, Hamid R, Valeri L, Paul L, Selhub J, Rodrigues EG, Silva F, Mia S, Mostofa MG, Quamruzzaman Q, Rahman M, Christiani DC. Arsenic is associated with reduced effect of folic acid in myelomeningocele prevention: a case control study in Bangladesh. Environmental Health. 2015 Apr 10;14(1):34. doi: 10.1186/s12940-015-0020-0.

Background: Arsenic induces neural tube defects in several animal models, but its potential to cause neural tube defects in humans is unknown. Our objective was to investigate the associations between maternal arsenic exposure, periconceptional folic acid supplementation, and risk of posterior neural tube defect (myelomeningocele) among a highly exposed population in rural Bangladesh.

Methods: We performed a case-control study that recruited physician-confirmed cases from community health clinics served by Dhaka Community Hospital in Bangladesh, as well as local health facilities that treat children with myelomeningocele. Controls were selected from pregnancy registries in the same areas. Maternal arsenic exposure was estimated from drinking water samples taken from wells used during the first trimester of pregnancy. Periconceptional folic acid use was ascertained by self-report, and maternal folate status was further assessed by plasma folate levels measured at the time of the study visit.

Results: Fifty-seven cases of myelomeningocele were identified along with 55 controls. A significant interaction was observed between drinking water inorganic arsenic and periconceptional folic acid use. As drinking water inorganic arsenic concentrations increased from 1 to 25 μg/L, the estimated protective effect of folic acid use declined (OR 0.22 to 1.03), and was not protective at higher concentrations of arsenic. No main effect of arsenic exposure on myelomeningocele risk was identified.

Conclusions: Our study found a significant interaction between drinking water inorganic arsenic concentration from wells used during the first trimester of pregnancy and reported intake of periconceptional folic acid supplements. Results suggest that environmental arsenic exposure reduces the effectiveness of folic acid supplementation in preventing myelomeningocele.

Click here for paper.

Earth Day Celebrants Trash the Earth

I was a senior in high school when the first earth day was held. Living in the Washington DC area at the time I remember it well. Now it’s just a vacuous political stunt.  Consider this report from the Washington Post.

“A rank odor that visitors likened to cow deposits was borne on the breeze this week from a large mud flat left behind from Saturday’s Global Citizen 2015 Earth Day rally, just northeast of the Monument.” click here

Did these protesters have a CWA Section 404 permit to disturb this wetland habitat?

happy-bouncing-smilie

Attempting to Link Waterborne Infections with Undefined “Climate Change” Remains Futile

Confounding factors stymie efforts to link waterbore infections with an undefined “Climate Change.” Climate is a dynamic system. Let’s just assume that changes in climate may result in waterborne infections unless sufficient drinking water treatment, wastewater treatment, sanitation, and hygiene are provided as surface water quality deteriorates. Let’s move forward. Perhaps this is the reason more studies like this have not been performed – a paper gets published, but that’s about it for usefulness.

Guzman Herrador BR, de Blasio BF, MacDonald E, Nichols G, Sudre B, Vold L, Semenza JC, Nygård K. Analytical studies assessing the association between extreme precipitation or temperature and drinking water-related waterborne infections: a review. Environmental Health. 2015 Mar 27;14(1):29. doi: 10.1186/s12940-015-0014-y.

Determining the role of weather in waterborne infections is a priority public health research issue as climate change is predicted to increase the frequency of extreme precipitation and temperature events. To document the current knowledge on this topic, we performed a literature review of analytical research studies that have combined epidemiological and meteorological data in order to analyze associations between extreme precipitation or temperature and waterborne disease.A search of the databases Ovid MEDLINE, EMBASE, SCOPUS and Web of Science was conducted, using search terms related to waterborne infections and precipitation or temperature. Results were limited to studies published in English between January 2001 and December 2013.Twenty-four articles were included in this review, predominantly from Asia and North-America. Four articles used waterborne outbreaks as study units, while the remaining articles used number of cases of waterborne infections. Results presented in the different articles were heterogeneous. Although most of the studies identified a positive association between increased precipitation or temperature and infection, there were several in which this association was not evidenced. A number of articles also identified an association between decreased precipitation and infections. This highlights the complex relationship between precipitation or temperature driven transmission and waterborne disease. We encourage researchers to conduct studies examining potential effect modifiers, such as the specific type of microorganism, geographical region, season, type of water supply, water source or water treatment, in order to assess how they modulate the relationship between heavy rain events or temperature and waterborne disease. Addressing these gaps is of primary importance in order to identify the areas where action is needed to minimize negative impact of climate change on health in the future.

Click here for article.