Risk Assessment of Pharmaceuticals in the Saint Lawrence River Basin, Canada

Grill G, Khan U, Lehner B, Nicell J, Ariwi J. Risk assessment of down-the-drain chemicals at large spatial scales: Model development and application to contaminants originating from urban areas in the Saint Lawrence River Basin. The Science of the total environment 2015 Oct 1;541:825-838. doi: 10.1016/j.scitotenv.2015.09.100.

Chemicals released into freshwater systems threaten ecological functioning and may put aquatic life and the health of humans at risk. We developed a new contaminant fate model (CFM) that follows simple, well-established methodologies and is unique in its cross-border, seamless hydrological and geospatial framework, including lake routing, a critical component in northern environments. We validated the model using the pharmaceutical Carbamazepine and predicted eco-toxicological risk for 15 pharmaceuticals in the Saint-Lawrence River Basin, Canada. The results indicated negligible to low environmental risk for the majority of tested chemicals, while two pharmaceuticals showed elevated risk in up to 13% of rivers affected by municipal effluents. As an integrated model, our CFM is designed for application at very large scales with the primary goal of detecting high risk zones. In regulatory frameworks, it can help screen existing or new chemicals entering the market regarding their potential impact on human and environmental health. Due to its high geospatial resolution, our CFM can also facilitate the prioritization of actions, such as identifying regions where reducing contamination sources or upgrading treatment plants is most pertinent to achieve targeted pollutant removal or to protect drinking water resources.

Risk Assessment and Risk Management of Cyanotoxins

Ibelings BW, Backer LC, Kardinaal WE, Chorus I. Current approaches to cyanotoxin risk assessment and risk management around the globe. Harmful Algae. 2015 Dec;49:63-74.

Toxic cyanobacteria became more widely recognized as a potential health hazard in the 1990s, and in 1998 the World Health Organization (WHO) first published a provisional Guideline Value of 1 μg L-1 for microcystin-LR in drinking-water. In this publication we compare risk assessment and risk management of toxic cyanobacteria in 17 countries across all five continents. We focus on the three main (oral) exposure vehicles to cyanotoxins: drinking-water, water related recreational and freshwater seafood. Most countries have implemented the provisional WHO Guideline Value, some as legally binding standard, to ensure the distribution of safe drinking-water with respect to microcystins. Regulation, however, also needs to address the possible presence of a wide range of other cyanotoxins and bioactive compounds, for which no guideline values can be derived due to insufficient toxicological data. The presence of microcystins (commonly expressed as microcystin-LR equivalents) may be used as proxy for overall guidance on risk management, but this simplification may miss certain risks, for instance from dissolved fractions of cylindrospermopsin and cyanobacterial neurotoxins. An alternative approach, often taken for risk assessment and management in recreational waters, is to regulate cyanobacterial presence – as cell numbers or biomass – rather than individual toxins. Here, many countries have implemented a two or three tier alert level system with incremental severity. These systems define the levels where responses are switched from Surveillance to Alert and finally to Action Mode and they specify the short-term actions that follow. Surface bloom formation is commonly judged to be a significant risk because of the elevated concentration of microcystins in a scum. Countries have based their derivations of legally binding standards, guideline values, maximally allowed concentrations (or limits named otherwise) on very similar scientific methodology, but underlying assumptions such as bloom duration, average body size and the amount of water consumed while swimming vary according to local circumstances. Furthermore, for toxins with incomplete toxicological data elements of expert judgment become more relevant and this also leads to a larger degree of variation between countries’ thresholds triggering certain actions. Cyanobacterial blooms and their cyanotoxin content are a highly variable phenomenon, largely depending on local conditions, and likely concentrations can be assessed and managed best if the specific conditions of the locality are known and their impact on bloom occurrence are understood. Risk Management Frameworks, such as for example the Water Safety Plan concept of the WHO and the ‘bathing water profile’ of the European Union are suggested to be effective approaches for preventing human exposure by managing toxic cyanobacteria from catchment to consumer for drinking water and at recreational sites.

Shukla’s Gold: The ‘Largest Science Scandal in US History’ ?

Sure looks like it. This is what happens when government money tries to buy its own ‘science’.

“But his first, far bigger mistake, was his hubris in organizing the letter in the first place. It drew the attention of Shukla’s critics to something which, presumably, he would have preferred to keep secret: that for nearly 14 years, he, his family and his friends have been gorging themselves on taxpayers’ money at IGES; and that this money comes on top of the very generous salary he receives for doing much the same work at George Mason University (GMU).” click here for full article

Soil-Transmitted Helminth Infection

Echazú A, Bonanno D, Juarez M, Cajal SP, Heredia V, Caropresi S, Cimino RO, Caro N, Vargas PA, Paredes G, Krolewiecki AJ. Effect of Poor Access to Water and Sanitation As Risk Factors for Soil-Transmitted Helminth Infection: Selectiveness by the Infective Route. PLoS neglected tropical diseases. 2015 Sep 30;9(9):e0004111. doi: 10.1371/journal.pntd.0004111.

BACKGROUND: Soil-transmitted helminth (STH) infections are a public health problem in resource-limited settings worldwide. Chronic STH infection impairs optimum learning and productivity, contributing to the perpetuation of the poverty-disease cycle. Regular massive drug administration (MDA) is the cardinal recommendation for its control; along with water, sanitation and hygiene (WASH) interventions. The impact of joint WASH interventions on STH infections has been reported; studies on the independent effect of WASH components are needed to contribute with the improvement of current recommendations for the control of STH. The aim of this study is to assess the association of lacking access to water and sanitation with STH infections, taking into account the differences in route of infection among species and the availability of adequate water and sanitation at home.

METHODS AND FINDINGS: Cross-sectional study, conducted in Salta province, Argentina. During a deworming program that enrolled 6957 individuals; 771 were randomly selected for stool/serum sampling for parasitological and serological diagnosis of STH. Bivariate stratified analysis was performed to explore significant correlations between risk factors and STH infections grouped by mechanism of entry as skin-penetrators (hookworms and Strongyloides stercoralis) vs. orally-ingested (Ascaris lumbricoides and Trichuris trichiura). After controlling for potential confounders, unimproved sanitation was significantly associated with increased odds of infection of skin-penetrators (adjusted odds ratio [aOR] = 3.9; 95% CI: 2.6-5.9). Unimproved drinking water was significantly associated with increased odds of infection of orally-ingested (aOR = 2.2; 95% CI: 1.3-3.7).

CONCLUSIONS: Lack of safe water and proper sanitation pose a risk of STH infections that is distinct according to the route of entry to the human host used by each of the STH species. Interventions aimed to improve water and sanitation access should be highlighted in the recommendations for the control of STH.

Chronic Undernutrition Increases Susceptibility to Dental Fluorosis

This study is a good example of how the interpreters assumptions affect the conclusions drawn. Even at low concentrations fluorosis was observed in a portion of the exposed population.

M.E. Irigoyen-Camacho, A. García Pérez, A. Mejía González, R. Huizar Alvarez. Nutritional status and dental fluorosis among schoolchildren in communities with different drinking water fluoride concentrations in a central region in Mexico. Science of The Total Environment. Volume 541, 15 January 2016, Pages 512–519

Poor water quality and under nutrition are important factors affecting the health of many communities in developing countries. The aims of this study were: i) to describe the fluoride water concentration and the hydrogeological conditions in a state located in the central region of Mexico ii) to measure the association between undernutrition and dental fluorosis in children living in communities with different drinking water fluoride concentrations in a state located in the central region of Mexico.

Methods: Field work was performed in the region to identify the prevailing groundwater flow characteristics and water wells were sampled to analyze water fluoride concentration. Children were selected from three communities that had different drinking water fluoride concentrations (i.e., 0.56, 0.70 and 1.60 mg/l). Fluoridated salt was available in these communities. The Thylstrup–Fejerskov Index (TFI) was used to assess dental fluorosis. Categories four or higher of this index involve changes in the entire tooth surface (ITF ≥ 4). The weight and height of the children were measured. The assessment of undernutrition was based on the World Health Organization criteria: children were classified as being at risk of low-height (Height-for-Age Z score < − 1.0 SD) and having low-height (Height-for-Age Z score < − 2.0 SD) for age and sex, the same cutoff points of the Z score were used to classify risk of low-weight and low-weight children.

Results: In the region the mineralization of the water captured by the wells is the result of a reaction with volcanic materials. The water fluoride concentration in the region ranged from 0.2 to 1.60 mg/l. A total of 734 schoolchildren participated in the study. The percentage of children in fluorosis categories (ITF ≥ 4) was 15.9%, 21.1% of the children were at risk of low height-for-age, and 8.0% had low height-for-age. The percentage of children with fluorosis (ITF ≥ 4) was 6.3%, 9.1% and 31.9% (p < 0.001) and low high-for-age was 2.9%, 2.5% and 8.4% (p < 0.001), for the communities with F concentrations of 0.56 mg/l, 0.70 mg/l and 1.60 mg/l, respectively. The logistic regression model showed an association between dental fluorosis (TFI ≥ 4) and low height-for-age (OR 2.27 p < 0.001) after adjusting for sex, number of teeth erupted, source of drinking water, use of fluoridated toothpaste and tap water fluoride concentration in the community.

Conclusion: Children with low height-for-age were more likely to have dental fluorosis in the TFI categories that affect the entire tooth surface. The results suggest that subpopulations with chronic undernutrition are more susceptible to dental fluorosis.

Water Vapor Cools the Earth Surface via Changes in Heat Capacity

An important but very technical point regarding lapse rate as it relates to a theoretically pure (N2) atmosphere is discussed here

At issue is the relevance of the  Arrhenius radiative greenhouse theory. The Maxwell et al gravito-thermal greenhouse effect is replacing “Arrhenius” as the best science-based explanation.   

Microbiological Evaluation of Electric Kettles; Rural China

Cohen A, Tao Y, Luo Q, Zhong G, Romm J, Colford JM Jr, Ray I. Microbiological Evaluation of Household Drinking Water Treatment in Rural China Shows Benefits of Electric Kettles: A Cross-Sectional Study. PloS one. 2015 Sep 30;10(9):e0138451. doi: 10.1371/journal.pone.0138451. 

BACKGROUND: In rural China ~607 million people drink boiled water, yet little is known about prevailing household water treatment (HWT) methods or their effectiveness. Boiling, the most common HWT method globally, is microbiologically effective, but household air pollution (HAP) from burning solid fuels causes cardiovascular and respiratory disease, and black carbon emissions exacerbate climate change. Boiled water is also easily re-contaminated. Our study was designed to identify the HWT methods used in rural China and to evaluate their effectiveness.

METHODS: We used a geographically stratified cross-sectional design in rural Guangxi Province to collect survey data from 450 households in the summer of 2013. Household drinking water samples were collected and assayed for Thermotolerant Coliforms (TTC), and physicochemical analyses were conducted for village drinking water sources. In the winter of 2013-2104, we surveyed 120 additional households and used remote sensors to corroborate self-reported boiling data.

FINDINGS: Our HWT prevalence estimates were: 27.1% boiling with electric kettles, 20.3% boiling with pots, 34.4% purchasing bottled water, and 18.2% drinking untreated water (for these analyses we treated bottled water as a HWT method). Households using electric kettles had the lowest concentrations of TTC (73% lower than households drinking untreated water). Multilevel mixed-effects regression analyses showed that electric kettles were associated with the largest Log10TTC reduction (-0.60, p<0.001), followed by bottled water (-0.45, p<0.001) and pots (-0.44, p<0.01). Compared to households drinking untreated water, electric kettle users also had the lowest risk of having TTC detected in their drinking water (risk ratio, RR = 0.49, 0.34-0.70, p<0.001), followed by bottled water users (RR = 0.70, 0.53-0.93, p<0.05) and households boiling with pots (RR = 0.74, 0.54-1.02, p = 0.06).

CONCLUSION: As far as we are aware, this is the first HWT-focused study in China, and the first to quantify the comparative advantage of boiling with electric kettles over pots. Our results suggest that electric kettles could be used to rapidly expand safe drinking water access and reduce HAP exposure in rural China.