Influence of Phoslock® on legacy phosphorus, nutrient ratios, and algal assemblage composition in hypereutrophic water resources

Abstract

Acceleration of eutrophication in freshwater resources can result in prolific growth of nuisance algae, notably cyanobacteria. In this research, we evaluated the ability of an in situ P binding technology (Phoslock®) to alter available water column and sediment P, and the subsequent impact on nutrient ratios and algal assemblage composition. Two golf course irrigation ponds with legacy nutrient loads and chronic cyanobacterial blooms were treated with Phoslock and monitored for 2 years post-treatment. Phoslock significantly (P < 0.05) decreased water column total P levels and shifted mobile sediment P fractions (i.e., labile, reductant-soluble, organic) to the residual fraction. Total N/P ratios (by mass) significantly increased and were sustained at over 30:1 in the Hickory Meadows irrigation pond and 100:1 in the Chockyotte irrigation pond throughout the study. Consequent changes in the algal assemblage included decreases in dominance and overall density of cyanobacteria as well as a shift away from scum-forming genera (e.g., Microcystis spp. and Anabaena [Dolichospermum] sp.) to planktonic forms (e.g., Pseudanabaena sp. and Planktolyngbya sp.). This research provides information regarding mitigation of in situ water and sediment P toward shifting nutrient ratios and altering algal assemblage composition.

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IJERPH, Vol. 14, Pages 1472: The Moderating Effects of Students’ Personality Traits on Pro-Environmental Behavioral Intentions in Response to Climate Change

IJERPH, Vol. 14, Pages 1472: The Moderating Effects of Students' Personality Traits on Pro-Environmental Behavioral Intentions in Response to Climate Change

International Journal of Environmental Research and Public Health doi: 10.3390/ijerph14121472

Authors: Tai-Yi Yu Tai-Kuei Yu

This study developed a model that examined the relationship between undergraduate students' beliefs, norms and pro-environment behavioral intentions in the context of global climate change (GCC). The model was further evaluated to determine whether latent variables, such as sustainability value, environmental concern, social norms, perceived risk, pro-environmental attitude, as defined by the theory of planned behavior and value-belief-norm theory, significantly influenced students' intentions towards pro-environmental behavior. The research model was empirically tested using data collected form 275 undergraduate students. Empirical results found support for four interaction effects of personality traits and the related latent variables of environmental attitude, including sustainability value, social norms, environmental concern and perceived risk. The impact of undergraduate students' environmental attitudes was moderated by personality traits. The findings of this research offer policy makers and enterprises better understandings of undergraduate students' attitudes and behavioral intentions towards GCC and promote the visibility of this issue.

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Association of urinary concentrations of four chlorophenol pesticides with cardiometabolic risk factors and obesity in children and adolescents

Abstract

This study was undertaken to determine the association of four chlorophenol pesticides with cardiometabolic risk factors and obesity in children and adolescents. This cross-sectional study was conducted in 2016 on 242 children and adolescents, aged 6 to 18 years. The concentrations of 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), 2,4,5-trichlorophenol (2,4,5-TCP), and 2,4,6-trichlorophenol (2,4,6-TCP) in the urine were examined and their association with indices of obesity and cardiometabolic risk factors was determined. Multivariate linear regression and multinomial logistic regression analyses were applied. Overall, 242 participants with mean (SD) ages of 11.3 (2.5) years completed the survey. After adjustment for confounders, a significant positive association was found between body mass index (BMI) z-score and waist circumference (WC) with 2,5-DCP (0.07 (95% CI 0.04, 0.1)) and 0.79 (95% CI 0.54, 1.03), respectively. A significant association of 2,4,5-TCP was only found with WC (0.23 (95% CI 0.0, 0.46), but the relationship with 2,4-DCP was not significant. 2,5-DCP had a significant relationship only with obesity (1.09 (95% CI 1.1, 1.19)), while 2,4-DCP and 2,4,5-TCP showed no significant correlation with overweight or obesity. 2,4-DCP showed a significant positive relationship with high density lipoprotein-cholesterol (HDL-C). Moreover, 2,5-DCP showed a significant negative relationship only with systolic blood pressure and 2,4,5-TCP had a statistically significant inverse association with total cholesterol and HDL-C (−0.71 (95% CI −0.98, −0.45)). This study suggests potential associations of chlorophenol pesticides with overweight, obesity, lipid profile, and blood pressure in children and adolescents. Longitudinal studies are necessary to assess the clinical impact of these findings.

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Observed differentials in the levels of selected environmental contaminants among Mexican and other Hispanic American children, adolescents, adults, and senior citizens

Abstract

Starting with the 2007–2008 cycle, the National Health and Nutrition Examination Survey (NHANES) also oversampled Hispanics other than Mexicans (OHISP) making it possible to treat OHISP as a separate demographic group along with Mexican Americans (MAs), non-Hispanic whites (NHWs), and non-Hispanic blacks (NHBs). Yet, more often than not, OHISP have been merged with MA to form an all-Hispanic demographic group (HISP) thus limiting comparisons between NHW, NHB, and HISP. Consequently, for the first time, this study was undertaken to evaluate differences in the observed levels of selected environmental contaminants between MA and OHISP from five groups of environmental contaminants, namely, polycyclic aromatic hydrocarbons (PAHs), iodine uptake inhibitors (IUIs), environmental phenols (EPHs), priority pesticides (PPs), and perfluoroalkyl acids (PFAAs). Data for 2007–2010 from NHANES were used to conduct this study. OHISP children born in USA had higher levels of selected PAH metabolites than USA-born MA, and Mexican-born MA adolescents had higher levels of selected PAH metabolites than USA-born MA adolescents. USA-born adolescent MA had higher levels of selected parabens than USA-born adolescent OHISP, and OHISP adults born in another Spanish-speaking country had higher levels of selected parabens than USA-born OHISP adults. USA-born MA adults and seniors had higher levels of selected dichlorophenols than Mexico-born MA adults and seniors, respectively. Females had higher levels of selected PAH metabolites, EPHs, and PPs than males among children, adolescents, adults, and seniors, but the reverse was true for the levels of selected IUIs and PFAAs among adolescents and seniors. Smokers had higher levels of almost all PAH metabolites than non-smokers for adolescents, adults, and seniors. The same was true for urinary thiocynate for adolescents, adults, and seniors. OHISP is a multiracial multiethnic demographic group substantially different from MA with possibly different smoking behavior and with possibly differential levels of exposure to certain environmental contaminants and as such should be treated as a demographic group by itself.

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Ethanol traces in natural waters checked using a new DMFC enzymatic device

Abstract

The use of fuels with strong percentage of ethanol that is done in countries such as Brazil and Australia causes a more and more relevant presence of traces of ethanol in natural waters. The ethanol present in these fuels seems to contribute to increase, through various mechanisms, the concentration of hydrocarbons in the same waters and soil. The ethanol content in natural waters must therefore be monitored frequently. It was therefore proposed a very simple innovative method, based on a catalytic fuel cell with the alcohol dehydrogenase enzyme immobilized in the anodic compartment of the device. The analytical performances of this new device were then evaluated by checking traces of alcohol in different types of natural waters (rain, river, and groundwater), with a good degree of precision and with an acceptable level of accuracy.

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Correction to: Community reporting of ambient air polychlorinated biphenyl concentrations near a Superfund site

Abstract

The original version of this article unfortunately contains a mistake. The correct Author names should be Staci M. Rubin and Keri C. Hornbuckle.

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Assessment of three plant-based biodiesels using a Daphnia magna bioassay

Abstract

Biodiesel is an alternative fuel that is gradually replacing petroleum-based diesel use. Although biodiesel is considered friendlier to the environment, the potential toxic effects of biodiesel to aquatic organisms are still uncertain due to the wide range of feedstocks used to generate the fuel. The aquatic cladoceran Daphnia magna (D. magna) has been commonly used as a lethal and/or sub-lethal toxicological model organism in ecological risk assessments for contaminated water environments. In this work, we evaluated whether significant differences exist in the sensitivity of freshwater aquatic life to different biodiesels. The acute toxicity of three plant-based biodiesels was investigated using D. magna over a 96-h period. In addition, diesel fuel was tested as a reference. Increased immobility was observed as time progressed following exposure. Testing revealed of the four fuel products, diesel proved most toxic to D. magna, with half maximal effective concentration (EC₅₀) values of 4.7 μg/mL (24 h) and 3.4 μg/mL (72 h). Among the biodiesels, safflower methyl biodiesel was most toxic, with EC₅₀ values of 1026 μg/mL (24 h) and 71 μg/mL (48 h). Our data indicate that although not all biodiesels were toxic, the short-term exposure of D. magna to sub-lethal concentrations of biodiesels affects their mobility and thus decreases their reproductive potential. Overall, this research provides insights into the sub-lethal effects of biodiesels on an aquatic organism.

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