Risk Of Human Exposure Research Articles

Long-term spatiotemporal variation of benzo[a]pyrene in Japan: Significant decrease in ambient concentrations, human exposure, and health risk

Although Benzo[a]pyrene (BaP) is considered carcinogenic to humans, the health effects of exposure to ambient levels have not been sufficiently investigated. This study estimated the long-term spatiotemporal variation of BaP in Japan over nearly two decades at a fine spatial resolution of 1 km. This study aimed to obtain an accurate spatiotemporal distribution of BaP that can be used in epidemiological studies on the health effects of ambient BaP exposure. The annual BaP concentrations were estimated using an ensemble machine learning approach using various predictors, including the concentrations and emission intensities of the criteria air pollutants, and meteorological, land use, and traffic-related variables. The model performance, evaluated by location-based cross-validation, exhibited satisfactory accuracy (R2 of 0.693). Densely populated areas showed higher BaP levels and greater temporal reduction, whereas BaP levels remained higher in some industrial areas. The population-weighted BaP in 2018 was 0.12 ng m−3, a decrease of approximately 70% from its 2000 value of 0.44 ng m−3, which was also reflected in the estimated excess number of lung cancer incidences. Accordingly, the proportion of BaP exposure below 0.12 ng m−3, which is the BaP concentration associated with an excess lifetime cancer risk of 10−5, reached 67% in 2018. Our estimates can be used in epidemiological studies to assess the health effects of BaP exposure at ambient concentrations.

Occurrence of modified mycotoxins in Latin America: an up-to-date review.

The Latin America region has a considerable extent of varied climate conditions: from tropical, subtropical, and warm temperate to temperate. Among the surface territory, different agricultural products are produced, making them an important food source for human consumption. Fungal species commonly colonize those important agricultural products and often contaminate them with mycotoxins that have a major impact on health, welfare, and productivity. Nowadays, special attention is paid to modified mycotoxins, which are those that cannot be detected by conventional analytical methods. However, little data about their natural occurrence in food and feed is available, especially in Latin American countries, where, among all the countries in this region, only a few of them are working on this subject. Thus, the present review summarizes the published information available in order to determine the possible human exposure risk to these toxins.

Chemometric heavy metal contamination in tropical Indian estuaries: Implications for source identification

The impact of urban and industrial effluents in the tropical Indian estuaries (Ariankuppam backwater and Chunnambar River), east coast of India have been investigated in the present study by determining the degree of heavy metals contamination of the estuarine sediments. A total of 30 surface sediment samples were collected from both estuaries and were analyzed for trace metals, grain size and organic matter. The granulometric analysis reveals that both the estuaries are predominated by silty sand to sandy silt. The significant amount of organic matter (OM) in the Ariankuppam estuary sediment is due to natural (mangroves) and anthropogenic (pollution) organic input. Pearson correlation analysis reveals that there was a strong negative correlation of sand fraction with other sediment variables (silt, clay, and organic matter) and heavy metals, whereas a positive correlation was observed between silt+clay, organic matter, and heavy metals. The significant positive correlation of Fe with Ni, Cu, Pb and Zn presents Fe-Mn oxyhydroxides are the main controlling factor of heavy metals in both estuarine sediments. Cluster analysis and PCA helped to discriminate the station groups along both estuaries according to their sediment components and heavy metals. This study also revealed that sediment grain size is a key factor influencing organic matter and heavy metal accumulation in surface sediments. The calculated pollution indices such as Contamination factor (CF), Geoaccumulation Index (Igeo) and Pollution Load Index (PLI) values indicate that both estuaries are moderate to highly contaminated by Co and low to moderately contaminated by Pb and Zn. Based on the factor analysis, it is presumed that river runoff and industrial and untreated domestic wastes from lands are responsible for increased heavy metal concentration in both estuaries. Increased levels of metal contamination along the Union Territory of Puducherry coastline may increase the risk of human exposure to metals through the consumption of seafood, making the need for tougher regulations on the discharge of metals into the environment even more important.

New insights into removal efficacy of perfluoroalkyl substances by layered double hydroxide and its composite materials

Though the use of per-and polyfluoroalkyl substances (PFAS) is strictly restricted worldwide, PFAS have been increasingly detected in aqueous environment with high human exposure risk. Effective PFAS remediation requires the simultaneous concentration and decomposition of these compounds from dilute solutions, presenting a significant challenge. The present work evaluated the suitability of layered double hydroxide (LDH) materials, promising adsorbents for anionic pollutants, for the removal of long-chain and short-chain PFAS in micro-polluted water. Additionally, it explored their potential for PFAS degradation after modification. The results suggested that LDH adsorbents have limited ability to extract short-chain PFAS such as perfluorobutane sulfonate (PFBS) from water matrices, especially in dilute solutions. Although organic modification of LDHs could enhance their uptake efficacy on PFAS, it cannot improve the decomposition of PFAS. Innovatively, a composite featuring zero-valent iron (ZVI) particles coupled with LDH was developed, in which the nanoscale ZVI core is coated with LDH to adsorb and decompose perfluorooctanoic acid (PFOA) synergistically. Characterization of the composite showed that LDH coating not only hinders the aggregation of ZVI particles, but also reduces the passivation of ZVI. The PFOA removal efficacy of the composite can be further facilitated in acid environment. By-product analysis revealed that the composite decomposed PFOA mainly through decarboxylation and formation of unstable alcohol.

Bioaccumulation of legacy and emerging per- and polyfluoroalkyl substances in hydroponic lettuce and risk assessment for human exposure

Reclaimed water for irrigation or hydroponic cultivation provides exposure pathways for per- and polyfluoroalkyl substances (PFAS) to enter the human food chain. This study employed hydroponic methods to investigate the behavior of legacy PFAS and emerging chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs) in lettuce grown under environment-related exposure levels and assessed the human exposure risks from consuming contaminated lettuce. Overall, PFAS in lettuce were concentration-dependent, with long-chain PFAS tending to accumulate in roots and short-chain PFAS accumulating more in shoots. The enrichment of PFAS in lettuce was jointly influenced by their chain length and polar functional groups. Specifically, the root concentration factors (RCFs) of PFAS generally increased with increasing chain length, and RCF values of most perfluoroalkanesulfonic acids (PFSAs) were significantly higher than those of perfluoroalkyl carboxylic acids (PFCAs) with the same chain length (p < 0.01), while the translocation factors (TFs) exhibited opposite trends. RCF values of perfluorooctane sulfonate (PFOS) and its alternatives, Cl-PFESAs, were ranked as follows: 8:2 Cl-PFESA (mean: 139) > 6:2 Cl-PFESA (28.6) > PFOS (25.7), which was attributed to the increased molecular size and hydrophobicity resulting from the insertion of ether bonds and additional CF2 in 8:2 Cl-PFESA. Notably, TF value of 8:2 Cl-PFESA (mean: 0.007) was the smallest among all PFAS, indicating 8:2 Cl-PFESA was difficult to transfer to nutritional compartments. Adults and children would exceed the most conservative health-based reference dose (RfD) by consuming approximately 15.9–148 g and 7.92–74.0 g of contaminated lettuce per day, implying high health risks.

The level, human exposure, and health risk assessment of acrylamide in chips and breakfast cereals: A study from Türkiye

The aim of this study is to determine the acrylamide levels of corn chips, potato chips and breakfast cereals and to evaluate the acrylamide exposure level resulting from the consumption of these foods in terms of health risks. Firstly, the acrylamide levels of corn chips (n=19), potato chips (n=11), and breakfast cereals (n=20) were determined by liquid chromatography-tandem mass spectrometry. Then, the dietary acrylamide exposure resulting from chips and breakfast cereals consumption was calculated. Finally, dietary acrylamide exposure, target hazard quotient, the lifetime carcinogenic risk, and the margin of exposure approach values were calculated. The mean acrylamide levels of corn chips, potato chips, and breakfast cereals were 317±12, 3578±546, and 138±14 µg/kg, respectively. The mean acrylamide level of all chips was 1513±1876 µg/kg. The mean daily acrylamide exposure from the consumption of corn chips, potato chips, and breakfast cereals was calculated as 0.11±0.10, 1.28±0.58, and 0.08±0.06 µg/kg bw/day, respectively. The target hazard quotient values of acrylamide exposure from the consumption of corn chips, potato chips (except ketchup-flavored potato chips), and breakfast cereals are less than 1. However, the level of acrylamide exposure from the consumption of a total of 13 food samples−2 from corn chips, 10 from potato chips, and 1 from breakfast cereals−reaches alarming levels in terms of carcinogenic health risks. It is required that consumers reduce the frequency and amount of consumption of chips and breakfast cereals, especially potato chips. The results can serve as a guide for reducing exposure to acrylamide through chips and breakfast cereals consumption.

Screening for compounds with bioaccumulation potential in breast milk using their retention behavior in two-dimensional gas chromatography

Discovery of emerging pollutants in breast milk will be helpful for understanding the hazards to human health. However, it is difficult to identify key compounds among thousands present in complex samples. In this study, a method for screening compounds with bioaccumulation potential was developed. The method can decrease the number of compounds needing structural identification because the partitioning properties of bioaccumulative compounds can be mapped onto GC×GC chromatograms through their retention behaviors. Twenty pooled samples from seven provinces in China were analyzed. 1,286 compounds with bioaccumulation potential were selected from over 3,000 compounds. Sixty-two compounds, including aromatic compounds, phthalates, and phenolics etc., were identified with a high level of confidence and then quantified. Among them, twenty-seven compounds were found for the first time in breast milk. Three phthalate plasticizers and two phenolic antioxidants were found in significantly higher concentrations than other compounds. A toxicological priority index approach was applied to prioritize the compounds considering their concentrations, detection frequencies and eight toxic effects. The prioritization indicated that 13 compounds, including bis(2-ethylhexyl) phthalate, dibutyl phthalate, 1,3-di-tert-butylbenzene, phenanthrene, 2,6-di-tert-butyl-1,4-benzoquinone, 2,4-di-tert-butylphenol, and others, showed higher health risks. Meanwhile, some compounds with high risk for a particular toxic effect, such as benzothiazole and geranylacetone, were still noteworthy. This study is important for assessing the risks of human exposure to organic compounds.

Dog ectoparasites as sentinels for pathogenic Rickettsia and Bartonella in rural Guatemala.

Fleas and ticks serve as vectors of multiple pathogens in the genera Rickettsia and Bartonellathat cause diseases in humans and other animals. Although human rickettsiosis and bartonellosis have been reported in all countries in Central America, limited research has been conducted to investigate the natural cycles of flea- and tick-borne rickettsiosis and bartonellosis, especially in Guatemala. We evaluated dog parasites as sentinels for zoonotic disease risk in rural Guatemala by sampling ticks and fleas from dogs, which were then identified and individually screened for Rickettsia and Bartonella. A total of 77 households were surveyed and 80.52% of them had dogs. Overall, 133 dogs were examined for fleas and ticks, of which 68.42% had fleas and 35.34% had ticks. A total of 433 fleas and 181 ticks were collected from the infested dogs, with an additional 33 ticks collected from house walls. Three flea species were identified: Ctenocephalides felis (70%), Echidnophaga gallinacea(11.8%), and Pulex sp. (17.8%). Among the collected ticks, 97% were Rhipicephalus sanguineus with the rest being Amyblyomma cajennense, A. auricularium, and A. ovale. Rickettsia felis were detected in six C. felis, in one Pulex sp., and in two R. sanguineus, while Candidatus R. senegalensis was detected in one C. felis. Bartonella was detected only in fleas, including three Pulexsp. infected with B. vinsonii subsp. Berkhoffii, B. henselae, and Bartonella sp., respectively, and 11 C. felis infected with B. henselae. This study reports Candidatus R. senegalensis and B. vinsonii subsp. Berkhoffiiin Guatemala for the first time, and indicates the potential risk of human and dog exposure to Rickettsia and Bartonella species. These results show that dogs provide critical information relevant to managing human potential exposure to flea- and tick-borne pathogens in rural Guatemala.

Tissue distribution and exposure risk assessment of dioxins, dioxin-like polychlorinated biphenyls and perfluoroalkyl substances in red swamp crayfish

Significant attention has been paid to the adverse effects of dioxins, dioxin-like polychlorobiphenyls (DL-PCBs) and per-and polyfluoroalkyl substances (PFAS) in environment and food on ecosystem and human health. However, limited information exists regarding the occurrence, tissue distribution and exposure risk of these pollutants in crayfish. This study investigated tissue-specific distribution characteristics, influence factors and exposure risk of dioxins, DL-PCBs and PFAS in crayfish. Dioxins, DL-PCBs, and PFAS were detected in crayfish samples, with concentrations ranging from 0.361 to 1.91 pg TEQ g−1 for sum dioxins and DL-PCBs, and 1.54–21.2 ng g−1 for sum PFAS. The highest concentrations of dioxins, DL-PCBs TEQ and total PFAS were found in crayfish viscera and accounting for over 69% of the relative body burden (RBBs) of these pollutants. The specific-tissue distribution of these pollutants linked to tissue fat and protein content and log Kow and molecular weights of homologues. The consumption of crayfish edible tissue posed no health risks from exposure to dioxins and DL-PCBs as well as sum 4 PFAS in adults. However, consumption of crayfish viscera significantly increased exposure risk. This study can provide valuable insights into the tissue-specific distribution and human exposure risks associated with dioxins, DL-PCBs and PFAS in crayfish.

Polybrominated diphenyl ethers in indoor dust from Brazil: assessing demographic differences and human health exposure.

Indoor house dust is considered an important human exposure route to polybrominated diphenyl ethers (PBDEs), which has raised concern about their environmental persistence and toxicity properties. In this study, eight PBDEs (BDE-28, -47, -99, -100, -153, -154, -183, and -209) were determined in house dust from two cities with different socio-demographic characteristics from Brazil, examining possible relationships with factors that potentially influence contamination (population density, economic activities, presence of electronic equipment, and so on) and also estimating the risk of human exposure through oral ingestion and dermal contact. The Σ8PBDE concentration in Sorocaba city ranged between 380 and 4269ng/g dw, while in Itapetininga city ranged from 106 to 1000ng/g dw. In both regions, BDE-209 was the most abundantly found congener, followed by BDE-99. House dust from Sorocaba presented significantly greater concentrations of BDE-183 and BDE-209 than Itapetininga. Regarding risk exposure assessment, the estimated daily intake (EDI) of PBDEs was much lower than their respective reference doses (RfDs) in all pathways estimated (non-dietary ingestion and dermal contact). This study provided valuable data to improve the knowledge about the presence and exposure to PBDEs in Brazilian house dust in comparison to other developing countries and the need to control environmental pollution and protect human health.

Levels of Rare Earth Elements in Food and Human Dietary Exposure: A Review.

Rare earth elements (REEs) are a group consisting of the following 17 metals: Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Pm, Sc, Sm, Tb, Tm, Y and Yb. In the current century, the number of applications of REEs has significantly increased. They are being used as components in high technology devices of great importance industrial/economic. However, information on the risk of human exposure to REEs, as well as the potential toxic effects of these elements is still limited. In general terms, dietary intake is the main route of exposure to metals for non-occupationally exposed individuals, which should be also expected for REEs. The current paper aimed at reviewing the studies -conducted over the world- that focused on determining the levels of REEs in foods, as well as the dietary intake of these elements. Most studies do not suggest potential health risk for consumers of freshwater and marine species of higher consumption, or derived from the intake of a number of vegetables, fruits, mushrooms, as well as other various foodstuffs (honey, tea, rice, etc.). The current estimated daily intake (EDI) of REEs does not seem to be of concern. However, considering the expected wide use of these elements in the next years, it seems to be clearly recommendable to assess periodically the potential health risk of the dietary exposure to REEs. This is already being done with well-known toxic elements such as As, Cd, Pb and Hg, among other potentially toxic metals.

Polycyclic aromatic hydrocarbons (PAHs) in fish (Clarias gariepinus) of southwestern rivers, Nigeria: Occurrence, distribution, and potential human exposure risks

This study was undertaken to analyze Polycyclic aromatic hydrocarbons (PAHs) in fish (Clarias gariepinus) from six major rivers within southwest Nigeria to assess the ecotoxicological and human health risks. The average concentrations of total PAH (∑PAH) ranged from 12.18 to 49.12 µg/g and from 10.35 to 38.09 µg/g during the dry and wet seasons, respectively, and the ranges were significantly higher than the prescribed WHO (0.001 µg/g) and European Union (0.002 µg/g) recommended safe levels for human consumption. The low molecular weight PAHs (2–3 rings) dominated the profile, suggesting petrogenic sources. Phenanthrene remains the highest contributor to PAH intake across all locations and seasons. The toxicity equivalent quotients (TEQ), which represents the sum of B(a)P equivalent concentration [B(a)Peq] ranged from 0.851 to 2.014 μg BaP/g with a slightly higher range of 1.046–2.763 μg BaP/g during the dry and wet seasons, respectively. Across both seasons, the estimated hazard quotient (HQ) and hazard index (HI) were found to be < 1, suggesting consumption of Clarias gariepinus has no non-carcinogenic risks. The estimated excess cancer risk value (1.55×10−2 to 5.03×10−2) from consumption of C gariepinus exceeded all regulatory guideline values for potential cancer risk. The excess cancer risk, predominated by B(a,h)A (0.0194 µg/g) and B(a)P (0.0163 µg/g) suggests a greater risk of exposure during the wet season. The study showed no human health risk due to PAHs in Clarias gariepinus obtained from southwestern rivers in Nigeria. However, due to bioaccumulation, policies that will ensure regular monitoring of PAHs in seafood are recommended to maintain a sustainable ecosystem.

Detection of Ochratoxin A and Human Exposure Risk Assessment in Rasa roxburghii by SPE-UHPLC-MS/MS

Detection of Ochratoxin A and Human Exposure Risk Assessment in <em>Rasa roxburghii</em> by SPE-UHPLC-MS/MS

Carbapenemase gene blaOXA-48 detected at six freshwater sites in Northern Ireland discharging onto identified bathing locations.

Faecal contamination of surface waters has the potential to spread not only pathogenic organisms but also antimicrobial resistant organisms. During the bathing season of 2021, weekly water samples, from six selected coastal bathing locations (n=93) and their freshwater tributaries (n=93), in Northern Ireland (UK), were examined for concentrations of faecal indicator bacteria Escherichia coli and intestinal enterococci. Microbial source tracking involved detection of genetic markers from the genus Bacteroides using PCR assays for the general AllBac marker, the human HF8 marker and the ruminant BacR marker for the detection of human, and ruminant sources of faecal contamination. The presence of beta-lactamase genes blaOXA-48, blaKPC, and blaNDM-1 was determined using PCR assays for the investigation of antimicrobial resistance genes that are responsible for lack of efficacy in major broad-spectrum antibiotics. The beta-lactamase gene blaOXA-48 was found in freshwater tributary samples at all six locations. blaOXA-48 was detected in 83% of samples that tested positive for the human marker and 69% of samples that tested positive for the ruminant marker over all six locations. This study suggests a risk of human exposure to antimicrobial resistant bacteria where bathing waters receive at least episodically substantial transfers from such tributaries.

Non-invasive biomonitoring of polar bear feces can be used to estimate concentrations of metals of concern in traditional food.

The Arctic faces increasing exposure to environmental chemicals such as metals, posing health risks to humans and wildlife. Biomonitoring of polar bears (Ursus maritimus) can be used to quantify chemicals in the environment and in traditional foods consumed by the Inuit. However, typically, these samples are collected through invasive or terminal methods. The biomonitoring of feces could be a useful alternative to the current metal monitoring method within the Arctic. Here, we aim to 1) quantify the relationship between concentrations of metals in the feces and tissues (muscle, liver, and fat) of polar bears using predictive modeling, 2) develop an easy-to-use conversion tool for use in community-based monitoring programs to non-invasively estimate contaminant concentrations in polar bears tissues and 3) demonstrate the application of these models by examining potential exposure risk for humans from consumption of polar bear muscle. Fecal, muscle, liver, and fat samples were harvested from 49 polar bears through a community-based monitoring program. The samples were analyzed for 32 metals. Exploratory analysis indicated that mean metal concentrations generally did not vary by age or sex, and many of the metals measured in feces were positively correlated with the internal tissue concentration. We developed predictive linear regression models between internal (muscle, liver, fat) and external (feces) metal concentrations and further explored the mercury and methylmercury relationships for utility risk screening. Using the cross-validated regression coefficients, we developed a conversion tool that contributes to the One Health approach by understanding the interrelated health of humans, wildlife, and the environment in the Arctic. The findings support using feces as a biomonitoring tool for assessing contaminants in polar bears. Further research is needed to validate the developed models for other regions in the Arctic and assess the impact of environmental weathering on fecal metal concentrations.

Bisphenol S and Its Chlorinated Derivatives in Indoor Dust and Human Exposure.

Bisphenol S (BPS), an environmental endocrine disruptor, has been identified in global environmental matrices. Nevertheless, limited studies have investigated the presence of chlorinated analogues of BPS (Clx-BPSs) with potential estrogenic activities in environmental matrices. In this study, the occurrence of BPS and five types of Clx-BPSs was characterized in indoor dust (n = 178) from Hangzhou City. BPS was measurable in 94% of indoor dust samples, with an average level of 0.63 μg/g (<LD-2.4 μg/g). Among the detected Clx-BPSs homologues, Cl1-BPS (2-chloro-4-(4-hydroxyphenyl)sulfonylphenol; detection frequency 70%), Cl2-BPS-2 (2-chloro-4-(3-chloro-4-hydroxyphenyl)sulfonylphenol; 65%), and Cl2-BPS-1 (2,6-dichloro-4-(4-hydroxyphenyl)sulfonylphenol; 61%) were among the frequently detected Clx-BPSs. Cl1-BPS was the most abundant analyte, with an average of 0.048 μg/g (<LD-0.24 μg/g), followed by Cl2-BPS-1 (0.035 μg/g, <LD-0.14 μg/g), and Cl2-BPS-2 (0.031 μg/g, <LD-0.13 μg/g). Significant correlations in indoor dust concentrations were observed between BPS and Cl1-BPS (p < 0.01), as well as between BPS and Cl2-BPS-1 (p < 0.01). Moreover, an estimation was made for the total daily intake of Clx-BPSs via the ingestion of indoor dust by infants, children, and adults. This study presents the first evidence of the existence of Clx-BPSs in indoor dust, concurrently highlighting the necessity to address their potential human exposure risks.

Natural radioactivity in food crops and soil and estimation of the concomitant dose from tin mining areas in Nigeria

Mining of mineral ore is considered one of the anthropogenic sources of elevating the activity concentrations of the natural radionuclides in the environment, which in turn causes an increased risk of human exposure via the food chain. In an attempt to evaluate the radiological burdens resulting from tin mining activities in Nigeria, farm soil and sixty-two samples of different food crops grown around tin mining areas were evaluated for the activity concentrations of 226Ra, 232Th, and 40K using a high-purity germanium detector. The mean activity concentrations of 226Ra, 232Th and 40K in soil were 64.6 ± 29.5, 72.03 ± 28.73 and 680.6 ± 324.3 Bq/kg, respectively. These values were found to be higher than their corresponding world average values. However, the mean activity concentrations of the measured radionuclides in plants were below their respective world average values, as reported by UNSCEAR. The overall average annual ingestion dose due to the consumption of the analysed plants was 151 µSv/y, which is below the reported world average value of 290 µSv/y. The results obtained show that the hazard indices were low enough to cause any immediate radiological health complications due to the ingestion of the crops grown in the studied areas.

Carry-over rate of per- and polyfluoroalkyl substances to raw milk and human exposure risks in different regions of China

The widespread presence of per- and polyfluoroalkyl substances (PFAS) in various environmental matrices and their adverse health effects have gained worldwide attention. Therefore, numerous studies have focused on human exposure to PFAS through different pathways, such as fish and drinking water, and little attention has been paid to milk consumption. This study aimed to explore the transfer of PFAS by investigating the occurrence of PFAS in cow feed, drinking water, and raw milk from 20 regions of China and to assess the risk of human exposure to PFAS from raw milk. In total, 13, 15, and 7 PFAS were detected in cow feed, drinking water, and raw milk with total concentrations (∑PFAS) of 5.59 ± 2.91 ng/g (mean ± standard deviation), 11.91 ± 23.12 ng/L, and 0.15 ± 0.13 ng/mL, respectively. Perfluoropentanoic acid (PFPeA) was dominant with a concentration of 2.28 ± 1.75 ng/g, approximately 40.7 % of ∑PFAS in feed. Perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA) were the dominant compounds found in drinking water at 4.80 ± 14.37 and 3.01 ± 6.06 ng/L, respectively. Additionally, PFOA (0.08 ± 0.09 ng/mL) was the most significant compound in raw milk, contributing 51.5 % of ∑PFAS. Moreover, the results of the carry-over rate (COR) were as follows: perfluorooctanesulfonic acid (PFOS, 29.58 %) > PFOA (15.78 %) > perfluorobutanesulfonic acid (PFBS, 9.45 %). According to the reference dose (RfD) established by the European Food Safety Authority (EFSA) in 2018, there is a potential toxicological hazard of PFOA exposure for preschool children through milk consumption. Notably, the health risk from PFOS for 1-year-old children in Central China exceeded that observed for humans in other regions and age groups. Our results showed that PFOS and PFOA were more likely to accumulate in cows and to be constantly transferred to milk, thus increasing the human health risk, especially in children.

Per- and polyfluoroalkyl substances in Chinese commercially available red swamp crayfish (Procambarus clarkii): Implications for human exposure and health risk assessment

The extensive utilization of per- and polyfluoroalkyl substances (PFASs) has led to their pervasive presence in the environment, resulting in contamination of aquatic products. Prolonged exposure to PFASs has been linked to direct hepatic and renal damage, along with the induction of oxidative stress, contributing to a spectrum of chronic ailments. Despite the recent surge in popularity of red swamp crayfish as a culinary delicacy in China, studies addressing PFASs' exposure and associated health risks from their consumption remain scarce. To address this gap, our study investigated the PFASs’ content in 85 paired edible tissue samples sourced from the five primary red swamp crayfish breeding provinces in China. The health risks associated with dietary exposure were also assessed. Our findings revealed widespread detection of PFASs in crayfish samples, with short-chain perfluoroalkyl carboxylic acids (PFCAs) exhibiting the highest concentrations. Notably, the total PFAS concentration in the hepatopancreas (median: 160 ng/g) significantly exceeded that in muscle tissue (5.95 ng/g), as did the concentration of every single substance. The hazard quotient of perfluorohexanesulfonic acid (PFHxS) via consuming crayfish during peak season exceeded 1. In this case, a potential total non-cancer health risk of PFASs, which is mainly from the hepatopancreas and associated with PFHxS, is also observed (hazard index>1). Thus, it is recommended to avoid consuming the hepatopancreas of red swamp crayfish. Greater attention should be paid to governance technology innovation and regulatory measure strengthening for short-chain PFASs.

Occurrence of antibiotic-resistant bacteria in household greywater discharged into the environment in Burkina Faso's Sahel region

ABSTRACT The prevalence and antibiotic resistance of Salmonella spp. and Staphylococcus spp. from greywater were investigated in Africa's Sahel region, Burkina Faso. A total of 36 and 56 isolates of Salmonella spp. and Staphylococcus spp. were isolated from greywater, respectively. From the Salmonella spp. isolates, resistance was most frequently observed against vancomycin (69%), ampicillin (61%), cefoxitin (42%), trimethoprine/sulfamethoxazole (36%), amoxicillin-clavunal acid (33%) and tetracycline (33%). For all Staphylococcus spp. isolates, the highest rate of resistance was against penicillin (55.36%) followed by oxacillin (48.21%) and clindamycin (30.36%). In addition, 75% of the isolated Salmonella spp. strains were resistant to at least two antibiotics of different families, while 30.35% of Staphylococcus spp. strains were multidrug-resistant (MDR). Overall, this is one of the first studies reporting the presence of MDR bacteria in untreated greywater discharged from domestic activities in Burkina Faso. Our results show that untreated greywater can contain bacteria resistant to antibiotics used in therapeutic care. Therefore, uncontrolled discharge of untreated greywater into the environment could lead to the dissemination of resistant bacteria and resistance genes in the environment and increase the risk of human exposure to antimicrobial resistance.