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Perfluorinated alkyl substances (PFAS) were determined in human milk samples (n = 664) from participants in the Maternal-Infant Research on Environmental Chemicals (MIREC) study. ΣPFAS concentrations (sum of seven PFAS) ranged from 3.1 ng L -1 to 603 ng L -1 , with a median concentration of 106 ng L -1 in the Canadian mothers' milk analyzed. These data comprise the first pan-Canadian dataset of PFAS in human milk. Perfluorooctanoic acid (PFOA) and linear perfluorooctanesulfonate (L-PFOS) were the dominant contributors to ΣPFAS in human milk samples. An inverse relationship between ΣPFAS concentrations and age was observed (Spearman correlation - 0.184). Primiparous women had elevated PFAS concentrations in milk relative to women who had children previously (p < 0.001). In contrast, the region of maternal birth did not influence ΣPFAS concentrations (p = 0.156). Although China and Norway have observed consistently detectable levels of perfluoroundecanoic acid (PFUdA) in human milk, PFAS with long carbon chains (n ≥ 11) were not present above method detection limits in Canadian human milk samples analyzed as part of the MIREC study. In conclusion, despite the presence of low levels of environmental contaminants in human milk, Health Canada supports breastfeeding due to the benefits to both infants and mothers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2022. Published by Elsevier B.V. All rights reserved.)

China is the world's largest pesticide user. These chemicals are bioaccumulative in the human body, and eventually could be transferred from the mother to the fetus/infant via placental and breastfeeding transport, which might pose developmental deficiency risks. In this study, human biomonitoring of legacy pesticides was conducted in three Chinese cities using 60 breast milk samples. The patterns, chemical structural signatures, and the estimated daily intake of pesticides were assessed. The median concentration of HCB (57.8 ng g -1 lw, Interquartile range: 28.5-76.9 ng g -1 lw) was the highest among all pesticides, whereas the HCHs, DDXs, TCVP, and heptachlor were also detected. A significantly different pattern of pesticides was found among three sampling cities: the Mianyang cases were mostly DDXs oriented while the Wuhan and Hangzhou cases were under HCB, HCHs, TCVP, and heptachlor influences. Maternal age and pre-pregnancy BMI were found to be the influencing factors for the pesticides in the breast milk, and dietary preferences were an important factor in the exposure scenario. Chemical structural signatures indicated that for HCHs and DDXs the exposure was mostly historical, while the lindane and dicofol exposure may exist among the volunteering mothers. The EF for chiral pesticides did not deviate significantly from the racemic value. The risk from breastfeeding was negligible according to the Chinese and UN standard, while some cases from Hangzhou and Wuhan exceeded the Canadian restrictions. Thus, the adverse health effects of chemical exposure by dietary intake for infants need to be closely monitored in future studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The Three Gorges Reservoir (TGR) underwent staged impoundment of water from 135 m to 175 m between 2003 and 2010. Periodic water impoundment was divided into drainage (March to early June), low water level (June to August), impoundment (September to October), and high water level (November to February) period. However, the impact of the Three Gorges Dam (TGD) and staged impoundment on water quality, especially in the long term, remains unclear. Herein, hydrological, pollution load, nutrient, and biochemical indices were determined for the TGR during 1998-2018. The Canadian Council of Ministers of the Environment Water Quality Index, a K-means clustering algorithm, and the Mann-Kendall (MK) test were applied to this data to explore the spatial and temporal distribution of water quality. The results show that water quality was good overall, but it before the full impoundment stage (2010) was worse than after that. The low water level period had the worst water quality among the four periods, and spatially, midstream was worst. Among water quality indices, the median total nitrogen (TN) and total phosphorus (TP) were in the range of 1.505-2.303 and 0.071-0.176 mg/L, respectively, and these were the key pollution indices. In addition, due to differences in hydrological and hydrodynamic conditions, and the regional distribution of pollution sources, water quality in the TGR displayed temporal and spatial heterogeneity. TN, TP, potassium permanganate index (COD Mn ), five-day biochemical oxygen demand (BOD 5 ) and Escherichia coli (E. coli) were maximal during the low water level period, and TN, TP and E. coli were highest in midstream. MK test results revealed that nutrients pollution became worse midstream, and a gradual increase in TP caused severe algal blooms downstream. Therefore, nutritional water treatment and non-point source pollution control should be the focus of future work., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

N-nitrosamines are potent carcinogens, particularly N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA), which are commonly found in a variety of foods and drinking water. We calculated the food and drinking water intakes of NDMA, NDEA, and total volatile nitrosamines (TVNA) by Chinese residents in different provinces by multiplying the reported total diet study results by the nitrosamine contents in food and drinking water. The weighted content of nitrosamines in each category of foods and the concentration of nitrosamines in drinking water was obtained through literature review. The exogenous NDMA, NDEA and TVNA intakes of adult residents in 20 provinces ranged from 171 to 425 ng/d, 41 to 140 ng/d and 373 to 1028 ng/d, respectively. The main contributors to NDMA and TVNA intakes were vegetables, cereals, aquatic products, and meats while the main sources of NDEA intake were vegetables and cereals. The average total NDMA intake per capita in China (251 ng/d) was similar to that in Germany in 1991 (231 ng/d) but higher than that in the United States (136 ng/d), Canada (87.6 ng/d) and France (188 ng/d). Large differences in nitrosamine intakes were observed between the coastal provinces and inland provinces. Drinking water was estimated to contribute 13.1%, 1.3% and 10.8% of the exogenous intakes of NDMA, NDEA and TVNA, respectively. Based on our results, we recommend setting the NDMA drinking water criterion of 40 ng/L. Overall, this study presents basic information regarding nitrosamines intake via food and drinking water in China that will facilitate risk assessment, generation of health advisories and policy making., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Glyphosate (Gly) is a broad-spectrum herbicide and currently one of the most studied pesticides. New Gly-related data are published daily worldwide. Despite the large number of publications, there is no published scientometric revision that presently addresses this issue systematically. We aimed to scientometrically analyze the publication patterns of main topics related to Gly research. Web of Science data was obtained searching the topic "Glyphosate" (10,069 publications). Toxicology was the most influential area, and a subset was delimited containing the categories "Environmental Sciences", "Toxicology" and "Ecology" (2077 publications). The datasets were analyzed using Citespace. The publications number presented a high correlation with the Gross Domestic Product (GDP) in both datasets. USA was the leader of general publication about Gly, followed by Brazil, Canada and China. USA, Canada, Argentina, China and Brazil were the main countries in Gly toxicology. This subset was related with data of the GDP spending on Research & Developing and with the number of researchers by country. Thus, we ranked the main countries interested in the Gly and its toxicology and that invest their economic and human resources in these researches. Based on a keyword analysis by CiteSpace of the Gly toxicology, it was highlighted the "glyphosate-induced habitat alteration", that reflected the concern about Gly impact on agricultural and natural ecosystems. The researchers are also focused in studies involving AMPA (aminomethylphosphonic acid), the main Gly degradation product, the genotoxicity, herbicides mixture and in its presence in drinking water. More researches about Gly genotoxicity and carcinogenicity to humans are needed and more studies to compile the results of independent researches, such as meta-analytical reviews. Our study can support decisions and future efforts about Gly impacts and use, since more sustainable agriculture with less environment impact is important to the maintenance of ecosystem services and consequently the human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)