Temporal trends in radiometrically dated sediment cores from English lakes show polybrominated diphenyl ethers correlate with brominated but not mixed bromo/chloro dioxins and furans

This paper reports concentrations between ~1950 and present, of polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins and furans (PBDD/Fs), in radiometrically-dated sediment cores from three English lakes. Mixed bromo/chloro dibenzo-p-dioxins and furans (PXDD/Fs) were measured in two of the same lakes. Concentrations of PXDD/Fs decreased over time to the present. To our knowledge, this is the first report of temporal trends of PXDD/Fs in the environment. In contrast, concentrations of PBDEs increased towards the present and were significantly correlated (R = 0.88–0.98; p < 0.05) with concentrations of PBDFs in all three lakes. These observations suggest that the sources of PXDD/Fs are not related to PBDEs and differ from those of PBDFs. We also report for the first time the presence of octabromodibenzofuran (OBDF) in the two most recent core slices at one lake. The source of OBDF in these samples is unclear. While OBDF has been reported previously as a significant contaminant of some commercial formulations of Deca-BDE, it is also present in Octa-BDE products and in emissions from a variety of combustion activities. Overall, while the positive correlation between PBDEs and PBDFs suggests increased use of PBDEs has contributed substantially to environmental contamination with PBDFs; examination of PBDF homologue patterns implies emissions from combustion activities are likely also important

Current use pesticides in soil and air from two agricultural sites in South Africa: implications for environmental fate and human exposure

Concerns about the possible negative impacts of current use pesticides (CUPs) for both the environment and human health have increased worldwide. However, the knowledge on the occurrence of CUPs in soil and air and the related human exposure in Africa is limited. This study investigated the presence of 30 CUPs in soil and air at two distinct agricultural sites in South Africa and estimated the human exposure and related risks to rural residents via soil ingestion and inhalation (using hazard quotients, hazard index and relative potency factors). We collected 12 soil and 14 air samples over seven days during the main pesticide application season in 2018. All samples were extracted, purified and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry. In soils, nine CUPs were found, with chlorpyrifos, carbaryl and tebuconazole having the highest concentrations (up to 63.6, 1.10 and 0.212 ng g(-1), respectively). In air, 16 CUPs were found, with carbaryl, tebuconazole and terbuthylazine having the highest levels (up to 25.0, 22.2 and 1.94 pg m(-3), respectively). Spatial differences were observed between the two sites for seven CUPs in air and two in soils. A large dominance towards the particulate phase was found for almost all CUPs, which could be related to mass transport kinetics limitations (non-equilibrium) following pesticide application. The estimated daily intake via soil ingestion and inhalation of individual pesticides ranged from 0.126 fg kg(-1) day(-1) (isoproturon) to 14.7 ng kg(-1) day(-1) (chlorpyrifos). Except for chlorpyrifos, soil ingestion generally represented a minor exposure pathway compared to inhalation (i.e. <5%). The pesticide environmental exposure largely differed between the residents of the two distinct agricultural sites in terms of levels and composition. The estimated human health risks due to soil ingestion and inhalation of pesticides were negligible although future studies should explore other relevant pathways

Are atmospheric PBDE levels declining in central Europe? Examination of the seasonal and semi-long-term variations, gas–particle partitioning and implications for long-range atmospheric transport

This study presents multi-year monitoring data on atmospheric polybrominated diphenyl ethers (PBDEs) in central Europe. Air was sampled on a weekly basis at a background site in the central Czech Republic from 2011 to 2014 (N = 114). Σ8PBDEs (without BDE209) total (gas and particulate) concentrations ranged from 0.084 to 6.08&thinsp;pg&thinsp;m−3, while BDE209 was at 0.05–5.01&thinsp;pg&thinsp;m−3. BDE47, BDE99 and BDE183 were the major contributors to Σ8PBDEs.Overall, the atmospheric concentrations of individual PBDEs were controlled by deposition processes, meteorological parameters and long-range atmospheric transport. Regarding gas–particle partitioning, with the exception of BDE28 (gaseous) and BDE209 (particulate), all congeners were consistently detected in both phases. Clear seasonal variations with significantly higher measured particulate fraction (θmeasured) in winter compared to summer was found for all PBDEs except BDE209. For example, while the average θmeasured of BDE47 was 0.53±0.19 in winter, this was only 0.01±0.02 in summer. Similarly, for BDE99, θmeasured was 0.89±0.13 in winter, while it was only 0.12±0.08 in summer. The observed gas–particle partitioning coefficient (Kp, in m3&thinsp;µg−1) was compared with three model predictions, assuming equilibrium or a steady state. None of the models could provide a satisfactory prediction of the partitioning, suggesting the need for a universally applicable model.Statistically significant decreases of the atmospheric concentrations during 2011–2014 were found for BDE99, 100, 153 and 209. Estimated apparent atmospheric halving times for these congeners ranged from 2.8 (BDE209) to 4.8 (BDE153) years. The results suggest that photolytic debromination to lower brominated congeners may significantly influence PBDE concentration levels and patterns in the atmosphere.</p

Seasonal variations in air concentrations of 27 organochlorine pesticides (OCPs) and 25 current-use pesticides (CUPs) across three agricultural areas of South Africa

For decades pesticides have been used in agriculture, however, the occurrence of legacy organochlorine pesticides (OCPs) and current-use pesticides (CUPs) is poorly understood in Africa. This study investigates air concentrations of OCPs and CUPs in three South African agricultural areas, their spatial/seasonal variations and mixture profiles. Between 2017 and 2018, 54 polyurethane foam-disks passive air-samplers (PUF-PAS) were positioned in three agricultural areas of the Western Cape, producing mainly apples, table grapes and wheat. Within areas, 25 CUPs were measured at two sites (farm and village), and 27 OCPs at one site (farm). Kruskal-Wallis tests investigated area differences in OCPs concentrations, and linear mixed-effect models studied differences in CUPs concentrations between areas, sites and sampling rounds. In total, 20 OCPs and 16 CUPs were detected. A median of 16 OCPs and 10 CUPs were detected per sample, making a total of 11 OCPs and 24 CUPs combinations. Eight OCPs (trans-chlordane, o,p'-/p,p'-dichlorodiphenyldichloroethylene (DDE)/dichlorodiphenyltrichloroethane (DDT), endosulfan sulfate, γ-hexachlorocyclohexane and mirex) and two CUPs (carbaryl and chlorpyrifos) were quantified in all samples. p,p'-DDE (median 0.14 ng/m(3)) and chlorpyrifos (median 0.70 ng/m(3)) showed the highest concentrations throughout the study. Several OCPs and CUPs showed different concentrations between areas and seasons, although CUPs concentrations did not differ between sites. OCPs ratios suggest ongoing chlordane use in the region, while DDT and endosulfan contamination result from past-use. Our study revealed spatial and seasonal variations of different OCPs and CUPs combinations detected in air. Further studies are needed to investigate the potential cumulative or synergistic risks of the detected pesticides

The role of the global cryosphere in the fate of organic contaminants

The cryosphere is an important component of global organic contaminant cycles. Snow is an efficient scavenger of atmospheric organic pollutants while a seasonal snowpack, sea ice, glaciers and ice caps are contaminant reservoirs on time scales ranging from days to millennia. Important physical and chemical processes occurring in the various cryospheric compartments impact contaminant cycling and fate. A variety of interactions and feedbacks also occur within the cryospheric system, most of which are susceptible to perturbations due to climate change. In this article, we review the current state of knowledge regarding the transport and processing of organic contaminants in the global cryosphere with an emphasis on the role of a changing climate. Given the complexity of contaminant interactions with the cryosphere and limitations on resources and research capacity, interdisciplinary research and extended collaborations are essential to close identified knowledge gaps and to improve our understanding of contaminant fate under a changing climate

Association of Glutathione S-Transferase Polymorphisms with Dietary Composition but Not Anthropometry in Obese as Well as Nonobese Individuals

OBJECTIVES: Glutathione S-transferases (GSTs) are detoxifying enzymes for a number of substrates, including some food compounds. Selected GST polymorphisms have been proven to significantly affect enzymatic activity; however, it is unclear whether this altered metabolism influences dietary composition. The objective of this study was to locate the correlation between GST polymorphisms and selected nutritional parameters, namely, fiber and vitamin C intake. METHODS: This study was conducted on a cohort of 472 individuals (mean age 45.26 years; mean body mass index [BMI] 32.36) from the South Moravian region of the Czech Republic. Basic anthropometrical parameters were measured and no association was found for the selected polymorphisms. Polymorphisms in GSTA1, GSTM1, and GSTT1 were genotyped using a polymerase chain reaction (PCR)-based methodology. Food intake was monitored using a self-administered 7-day questionnaire that was subsequently analyzed with a special focus on vitamin C intake, fiber intake, and total energy intake. RESULTS: For GSTA1 and GSTM1 polymorphisms, an association was observed with fiber intake. Though no association was found with vitamin C intake, mean vitamin C intake was found to be higher than recommended daily values. No association was found with either daily energy intake or anthropometric parameters. CONCLUSION: Based on our results, GST polymorphisms seem to affect dietary composition; however, they have no effect on total energy intake or any association with obesity