Environmental and dietary exposure of perfluorooctanoic acid and perfluorooctanesulfonic acid in the Nakdong River, Korea.

This study performed the first environmental and dietary exposure assessment to explore plant uptake of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from agricultural soil and irrigation water in the Nakdong River delta, South Korea. Annual average concentrations of total PFOA and PFOS ranged from 0.026 to 0.112 µg L-1 (irrigation water), and from 0.818 to 1.364 µg kg-1 (soil), respectively. PFOA and PFOS hotspots were identified downstream of the Nakdong River and were influenced by seasonal climatic variations. The observed average biennial concentration of the sum of PFOA and PFOS decreased in irrigation water, from 0.112 µg L-1 in 2013 to 0.026 µg L-1 in 2015, suggests that the 2013 Persistent Organic Pollutants Control Act may have helped to reduce levels of PFAS at this location. This study calculated some of the highest plant uptake factors reported to date, with values ranging from 0.962 in green onions to < 0.004 in plums. Leafy vegetables and rice are important components of the Korean diet; these groups had the largest contribution to the estimated dietary intake of PFOA and PFOS, which was calculated at 0.449 and 0.140 ng kg bw -1 day-1, respectively. This corresponded to 66.4% for PFOA and 7.9% for PFOS of the EFSA reference dose (RfD). The dietary intake of PFOA and PFOS from crops alone did not exceed the RfD. However, when the estimated daily intake (EDI) from other sources such as tap water, meat, fish, dairy, and beverages was included in the exposure risk assessment, both of the EDIs to PFOA and PFOS exceeded the RfDs, indicating that there may be a risk to human health. This study concludes that consumption of crops might, therefore, be a significant and underappreciated pathway for human exposure to PFAS.

Infant dietary exposure to dioxin-like polychlorinated biphenyls (dlPCBs), polybrominated and mixed halogenated dibenzo-p-dioxins and furans (PBDD/Fs and PXDD/Fs) in milk samples of lactating mothers in Accra, Ghana.

In this study, polybrominated and mixed halogenated dibenzo-p-dioxins and furans (PBDD/Fs and PXDD/Fs), and dioxin-like polychlorinated biphenyls (dlPCBs) were quantified in 24 human milk samples of first-time lactating mothers from Greater Accra region in Ghana. The aims of the study were to determine the concentrations and toxic equivalent concentrations of PBDD/F, PXDD/F and dlPCBs in human milk, and to estimate an infant's daily intake. The samples were analysed for 12 dioxin-like PCBs, 7 congeners of 2,3,7,8-polybrominated dibenzo-p-dioxins and furans (PBDD/Fs), and 7 congeners of 2,3,7,8-mixed halogenated dioxins and furans (PXDD/Fs, where X = Br/Cl). The mean concentrations in human milk ranged from 0.15 to 212.9 pg/g lipid for dlPCB congeners (mean TEQ: 1.67 pg WHO2005-TEQ/g lipid). Lesser concentrations for 2,3,7,8-PXDD/Fs (and PBDD/Fs congeners) ranged between <0.01-1.67 pg/g lipid, with a total mean tentative TEQ of 0.56 pg WHO2005-TEQ/g lipid. For an infant of average weight 7 kg, consuming an estimated volume of 600 mL human milk, the estimated average daily intake of dlPCBs in 21 human milk samples was 4.95 pg TEQ/kg bw/day; contributions from dlPCBs, PXDD/Fs and PBDD/Fs resulted in an average estimated daily intake of 6.56 pg TEQ/kg bw/day. The results obtained in this study, although lower than infant dietary intake estimates in human milk from industrialized countries, exceeded the recommended safety standards of 1 pg TEQ/kg bw/day and 1-4 pg TEQ/kg bw/day from the Agency for Toxic Substances and Disease Registry (ATSDR) and the World Health Organization (WHO), respectively.

A comparison of the effectiveness of QuEChERS, FaPEx and a modified QuEChERS method on the determination of organochlorine pesticides in ginseng.

This study provides a review of methods used in the determination of organochlorine pesticides (OCPs) in ginseng and compares the effectiveness of three extraction methods (Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS), a modified QuEChERS and a Fast Pesticide Extraction (FaPEx)) in the analyses of 20 OCPs in ginseng root samples. For each method, sample mass, solvent volume and sorbent mass were varied to identify the optimum combination to effectively isolate analytes of interest from the complex sample matrix. Extracts were analyzed using the gas chromatography-µ-electron capture detector (GC-µ-ECD), and confirmatory analyses performed by gas chromatography-tandem-mass spectrometry (GC-MS/MS). Eighteen out of 20 OCPs spiked onto in-house prepared ginseng samples produced acceptable recoveries (51-156%) when extracted using QuEChERS and FaPEx. All 20 analytes, including dichlorodiphenyldichloroethane (p, p'- DDD) and dichlorodiphenyltrichloroethane (o, p'-DDT), produced acceptable recoveries (51-129%) with the use of a modified QuEChERS method. The applicability of the modified QuEChERS method was demonstrated through the analysis of ginseng samples grown in endosulfan-treated soil. The samples were analyzed by both GC-µ-ECD and GC-MS/MS with no significant difference identified in the results of each analytical method. This study highlights the applicability of the modified QuEChERS method, in combination with GC- µ-ECD, to determine organochlorine pesticides in ginseng. This may be especially useful for laboratories in developing countries and less advanced institutions without access to MS/MS instrumentation.

The state of POPs in Ghana- A review on persistent organic pollutants: Environmental and human exposure.

Ghana is one of the top pesticide users and highest persistent organic pollutant (POP) emitters in sub-saharan Africa. Despite recent increases in published data, there is limited information on how POP concentrations have changed, post ratification of the Stockholm Convention. As a result, this review aims to address these knowledge gaps by collating available data that reported POPs in Ghanaian environmental matrices, identify spatial and temporal trends, and establish potential health risks. It is worth noting that Ghana has not developed its own regulatory standards for POPs, but adapts United States Environmental Protection Agency (USEPA) standards. Results obtained showed concentrations in excess of USEPA regulatory standards for per- and poly-fluoroalkyl sulphonates (PFASs) and dichlorodiphenyldichloroethane (DDD) in water, polychlorinated and polybrominated dibenzo-p-dioxins and furans (PCDD/Fs and PBDD/Fs) in e-waste soils, and polybrominated diphenyl ethers in aquatic organisms and dairy products. The published studies do not cover major regions nationwide. The inconsistency in methods and analytes measured, along with data scarcity in some regions, makes it challenging to identify temporal trends. However, the data did indicate decreasing concentrations of some legacy POPs in soil/sediment and aquatic organisms, with increasing concentrations of some POPs in water, fish, fruits and vegetables. Studies that performed health risks assessments were limited although the data indicated risks to e-waste workers, some farmers and vulnerable sub-populations. This review identified potential human health risks from POPs in the Ghanaian environment and the need for more consistent and widespread monitoring program.

Background levels of dioxin-like polychlorinated biphenyls (dlPCBs), polychlorinated, polybrominated and mixed halogenated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs & PXDD/Fs) in sera of pregnant women in Accra, Ghana.

Human exposure data on dioxins and dioxin-like compounds (DLCs) in Ghana are limited. Based on health risks associated with dioxins and DLCs, the impact of maternal body burdens on foetal exposure is significant. This is the first study that assesses polychlorinated, polybrominated and mixed halogenated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs and PXDD/Fs), and dioxin-like polychlorinated biphenyls (dlPCBs) in sera of primiparous Ghanaians. Our sample selection includes 34 participants from two municipalities (Accra and Tema), and explores contributions from environmental and dietary exposures using questionnaire data. Sample preparation involved C18 solid phase extraction, purification with acidified silica and lipid removal cartridges, and detection with gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry. The calculated average toxic equivalent concentration was 5.3 pg TEQ/g lw, with contributions from dlPCBs (1.25 pg TEQ/g lw), PCDD/Fs (3.10 pg TEQ/g lw), PBDD/Fs (0.49 pg TEQ/g lw) and PXDD/Fs (0.50 pg TEQ/g lw). The calculated total TEQ concentration was lower than background TEQ concentrations reported in sera of pregnant women globally. Positive correlations were obtained for total dioxins and DLC concentrations with age and Body Mass Index (BMI). Dietary intake of seafood and dairy products had a strong influence on PCDD/F and dlPCB concentrations. Statistically significant differences were observed for dioxins and DLCs in participants from Accra (in close proximity to Agbogbloshie e-waste site) and Tema. Given the significant TEQ contribution of PBDD/Fs and PXDD/Fs (~20%), it is essential to explore these classes of dioxins and DLCs in future biomonitoring studies as they may pose health risks, and add extra diagnostic information in source exposure investigations.