Parabens and triclosan in red swamp crayfish (Procambarus clarkii) from China: Concentrations, tissue distribution and related human dietary intake risk.

Parabens (PBs) and triclosan (TCS) are commonly found in pharmaceuticals and personal care products (PPCPs). As a result, they have been extensively found in the environment, particularly in aquaculture operations. Red swamp crayfish (Procambarus clarkii) consumption has significantly risen in China. Nevertheless, the levels of PBs and TCS in this species and the associated risk to human dietary intake remain undisclosed. This study assessed the amounts of five PBs, i.e., methyl-paraben (MeP), ethyl-paraben (EtP), propyl-paraben (PrP), butyl-paraben (BuP) and benzyl-paraben (BzP), as well as TCS in crayfish taken from five provinces of the middle-lower Yangtze River. MeP, PrP and TCS showed the highest detection rates (hepatopancreas: 46-86 %; muscle: 63-77 %) since they are commonly used in PPCPs. Significantly higher levels of ∑5PBs (median: 3.69 ng/g) and TCS (median: 7.27 ng/g) were significantly found in the hepatopancreas compared to the muscle (median: 0.39 ng/g for ∑5PBs and 0.16 ng/g for TCS) (p < 0.05), indicating bioaccumulation of these chemicals in the hepatopancreas. The estimated daily intake values of ∑5PBs and TCS calculated from the median concentrations of crayfish were 6.44-7.94 ng/kg bw/day and 11.4-14.0 ng/kg bw/day, respectively. Although no health risk was predicted from consuming crayfish (HQ <1), consumption of the hepatopancreas is not recommended.

Chronic exposure to tris(1,3-dichloro-2-propyl) phosphate: Effects on intestinal microbiota and serum metabolism in rats.

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphate ester that can adversely affect animal or human health. The intestinal microbiota is critical to human health. High-dose exposure to TDCIPP can markedly affect the intestinal ecosystem of mice, but the effects of long-term exposure to lower concentrations of TDCIPP on the intestinal flora and body metabolism remain unclear. In this study, TDCIPP was administered to Sprague-Dawley rats by gavage at a dose of 13.3 mg/kg bw/day for 90 days. TDCIPP increased the relative weight of the kidneys (P = 0.017), but had no effect on the relative weight of the heart, liver, spleen, lungs, testes, and ovaries (P > 0.05). 16 S rRNA gene sequencing revealed that long-term TDCIPP exposure affected the diversity, relative abundance, and functions of rat gut microbes. The serum metabolomics of the rats showed that TDCIPP can disrupt the serum metabolic profiles, result in the up-regulation of 26 metabolites and down-regulation of 3 metabolites, and affect multiple metabolic pathways in rat sera. In addition, the disturbed genera and metabolites were correlated. The functions of some disturbed gut microbes were consistent with the affected metabolic pathways in the sera, and these metabolic pathways were all associated with kidney disease, suggesting that TDCIPP may cause kidney injury in rats by affecting the intestinal flora and serum metabolism.

Estimated daily intake and cumulative risk assessment of organophosphate esters and associations with DNA damage among e-waste workers in Hong Kong.

Organophosphate esters (OPEs) are extensively used as additives in various products, including electronic equipment, which becomes e-waste when obsolete. Nevertheless, no study has evaluated OPEs exposure levels and the related health risks among e-waste workers in Hong Kong. Therefore, 201 first-spot morning urine samples were collected from 101 e-waste workers and 100 office workers to compare eight urinary OPE metabolites (mOPEs) levels in these groups. The concentrations of six mOPEs were similar in e-waste workers and office workers, except for significantly higher levels of diphenyl phosphate (DPHP) in e-waste workers and bis(1-chloro-2propyl) phosphate (BCIPP) in office workers. Spearman correlation analysis showed that most non-chlorinated mOPEs were correlated with each other in e-waste workers (i.e., nine out of ten pairs, including di-p-cresyl phosphate (DpCP) and di-o-cresyl phosphate (DoCP), DpCP and bis(2-butoxyethyl) phosphate (BBOEP), DpCP and DPHP, DpCP and dibutyl phosphate (DBP), DoCP and BBOEP, DoCP and DPHP, DoCP and DBP, BBOEP and DPHP, DPHP and DBP), indicating that handling e-waste could be the exposure source of specific OPEs. The median values of estimated daily intake (EDI) and hazard quotient (HQ) suggested that the health risks from OPEs exposures were under the recommended thresholds. However, linear regression models, Quantile g-computation, and Bayesian kernel machine regression found that urinary mOPEs elevated 8-hydroxy-2-deoxyguanosine (8-OhdG) levels individually or as a mixture, in which DPHP contributed prominently. In conclusion, although e-waste might not elevate the internal OPEs levels among the participating Hong Kong e-waste workers, attention should be paid to the potential DNA damage stimulated by OPEs under the currently recommended thresholds.

Identification of UDP-glucuronosyltransferase (UGT) isoforms involved in the metabolism of Chlorophenols (CPs).

Chlorophenols (CPs) are a group of pollutants that pose a great threat to the environment, they are widely used in industrial and agricultural wastes, pesticides, herbicides, textiles, pharmaceuticals and plastics. Among CPs, pentachlorophenol was listed as one of the persistent organic pollutants (POPs) by the Stockholm convention. This study aims to identify the UDP-glucosyltransferase (UGT) isoforms involved in the metabolic elimination of CPs. CPs' mono-glucuronide was detected in the human liver microsomes (HLMs) incubation mixture with co-factor uridine-diphosphate glucuronic acid (UDPGA). HLMs-catalyzed glucuronidation metabolism reaction equations followed Michaelis-Menten or substrate inhibition type. Recombinant enzymes and chemical reagents inhibition experiments were utilized to phenotype the main UGT isoforms involved in the glucuronidation of CPs. UGT1A6 might be the major enzyme in the glucuronidation of mono-chlorophenol isomer. UGT1A1, UGT1A6, UGT1A9, UGT2B4 and UGT2B7 were the most important five UGT isoforms for metabolizing the di-chlorophenol and tri-chlorophenol isomers. UGT1A1 and UGT1A3 were the most important UGT isoforms in the catalysis of tetra-chlorophenol and pentachlorophenol isomers. Species differences were investigated using rat liver microsomes (RLMs), pig liver microsomes (PLMs), dog liver microsomes (DLMs), and monkey liver microsomes (MyLMs). All these results were helpful for elucidating the metabolic elimination and toxicity of CPs.

Concentrations, sources and health risk of bisphenols in red swamp crayfish (Procambarus clarkii) from South-Eastern China.

Bisphenol analogs (BPs) are extensively employed in commercial and industrial products and they have been found in a variety of environmental matrices and human samples. The red swamp crayfish (Procambarus clarkii) has been a trendy food in China in recent decades. However, the levels of BPs in Chinese crayfish and the associated hazards of human exposure remain unknown. Thus, in this study, the levels of eight BPs in crayfish gathered from five major provinces engaged in crayfish within the Yangtze River Basin were analyzed. Additionally, the health risks for humans by ingesting crayfish were calculated. BPs were frequently detected in crayfish tissues, indicating the wide occurrence of these chemicals. In comparison to other substitutions, BPA remains the dominant bisphenol analog. Most of the BPs were observed to accumulate in the hepatopancreas compared to the muscle, so consuming the hepatopancreas of crayfish is not recommended. With the exception of BPS, the Estimated Daily Intakes (EDIs) of the remaining BPs exceeded the Tolerable Daily Intake (TDI) specified by the European Food Safety Authority (EFSA) by a factor of 1.75-69.0. The mean hazard index (HI) values exceeded 1 for both hepatopancreas and muscle in all provinces, and the mean HI values for hepatopancreas were significantly higher than those for muscle, indicating potential health risks for local consumers.

Isotemporal Substitution Modeling on Sedentary Behaviors and Physical Activity With Mortality Among People With Different Diabetes Statuses: A Prospective Cohort Study From the National Health and Nutrition Examination Survey Analysis 2007-2018.

BACKGROUND: To assess the associations of replacing sedentary behavior with different types of physical activity with mortality among the US adults of varying diabetes statuses. METHODS: This prospective cohort study included 21,637 participants (mean age, 48.5 y) from the National Health and Nutrition Examination Survey 2007-2018. Physical activity including leisure-time moderate-vigorous-intensity activity (MVPA), walking/bicycling, worktime MVPA, and sedentary behavior. We conducted an isotemporal substitution analysis using Cox regression to estimate the associations between replacements and mortality risks. RESULTS: We found significant protective associations between replacing 30 minutes per day sedentary behavior with 3 types of physical activity and all-cause, cardiovascular disease (CVD) mortality risk (except worktime MVPA for CVD mortality) among total participants, with hazard ratio (HR; 95% confidence interval [CI]) ranging from 0.86 (0.77-0.95) to 0.96 (0.94-0.98). Among participants with diagnosed diabetes, replacing sedentary behavior with leisure-time MVPA was associated with a lower all-cause mortality risk (HR 0.81, 95% CI, 0.70-0.94), which was also observed in other subgroups, with HRs (95% CI) ranging from 0.87 (0.80-0.94) to 0.89 (0.81-0.99). Among those with prediabetes/undiagnosed diabetes, replacing sedentary behavior with walking/bicycling was associated with lower CVD mortality risk, and replacement to work-time MVPA was associated with lower all-cause and CVD mortality risk, with HRs (95% CI) ranging from 0.72 (0.63-0.83) to 0.96 (0.92-0.99). CONCLUSIONS: Replacing sedentary behaviors with 30 minutes per day leisure-time MVPA was associated with lower all-cause mortality, regardless of diabetes statuses. Among people with prediabetes/undiagnosed diabetes, walking/bicycling was additionally associated with lower CVD mortality, and worktime MVPA was associated with lower all-cause and CVD mortality.

Dimethylcyclosiloxanes in Mobile Smart Terminal Devices: Concentrations, Distributions, Profiles, and Environmental Emissions.

Dimethylcyclosiloxanes (DMCs) are utilized as vital monomers in the synthesis of organosilicon compounds, integral to the manufacture of mobile smart terminal devices. Toxicological studies have revealed potential endocrine-disrupting activity, reproductive toxicity, neurotoxicity, and other toxicities of the DMCs. This study investigated the concentrations and composition profiles of seven DMCs, including hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and tetradecamethylcycloheptasiloxane (D7), hexadecamethylcyclooctasiloxane (D8), and octadecamethylcyclononasiloxane (D9) in three types of mobile smart terminal device components (silicone rubber, adhesive, and plastics). Environmental emissions of DMCs from silicone rubber materials were also estimated to improve the recognition of their potential fate within the environment. D5-D9 were widely present in silicone rubber and adhesives with detection rates ranging from 91-95.5% and 50-100%, respectively, while D3 and D4 were more frequently detected in plastics, both showing a detection rate of 61.1%. Silicone rubber had the highest total DMCs (∑7DMCs) and a concentration of 802.2 mg/kg, which were dominated by D7, D8, and D9. DMCs detected in adhesives were dominated by D4, D5, and D6. The estimated emission of ∑DMCs released into the environment in China from silicone rubber used in mobile smart terminal devices exceeds 5000 tons per year. Further studies are needed on the presence of DMCs in various commodities and environmental media to assess their ecological and human health impacts, as well as the toxicological effects of D7-D9 for the appropriate regulation of these chemicals.

Assessing Neurobehavioral Alterations Among E-waste Recycling Workers in Hong Kong.

Background: E-waste workers in Hong Kong are handling an unprecedented amount of e-waste, which contains various neurotoxic chemicals. However, no study has been conducted to evaluate the neurological health status of e-waste workers in Hong Kong. This study aimed to evaluate the prevalence of neurobehavioral alterations and to identify the vulnerable groups among Hong Kong e-waste workers. Methods: We recruited 109 Hong Kong e-waste workers from June 2021 to September 2022. Participants completed standard questionnaires and wore a GENEActiv accelerometer for seven days. Pittsburgh Sleep Quality Index and Questionnaire 16/18 (Q16/18) were used to assess subjective neurobehavioral alterations. The GENEActiv data generated objective sleep and circadian rhythm variables. Workers were grouped based on job designation and entity type according to the presumed hazardous level. Unconditional logistic regression models measured the associations of occupational characteristics with neurobehavioral alterations after adjusting for confounders. Results: While dismantlers/repairers and the workers in entities not funded by the government were more likely to suffer from neurotoxic symptoms in Q18 (adjusted odds ratio: 3.18 [1.18-9.39] and 2.77 [1.10-7.46], respectively), the workers from self-sustained recycling facilities also have poor performances in circadian rhythm. Results also showed that the dismantlers/repairers working in entities not funded by the government had the highest risk of neurotoxic symptoms compared to the lowest-risk group (i.e., workers in government-funded companies with other job designations). Conclusion: This timely and valuable study emphasizes the importance of improving the working conditions for high-risk e-waste workers, especially the dismantlers or repairers working in facilities not funded by the government.

Chlorate and perchlorate in tea leaves from major producing regions in China and related human exposure risk.

Chlorate and perchlorate are emerging pollutants that may interfere with thyroid function. Since they are highly water soluble, chlorate and perchlorate in tea leaves cause health concerns but have scarcely been studied. In this study, chlorate and perchlorate concentrations in 216 tea samples from different regions of China were determined. Perchlorate was detected in all the samples with a median concentration of 44.1 µg kg-1, while the chlorate detection frequency was 15.7%. We observed regional differences in perchlorate contents in tea leaves, with the highest quantity found in the central region of China. Except for dark tea, the concentration of perchlorate in tea infusions decreased with the increased number of times the tea leaves were brewed. The hazard quotients (HQs) of chlorate and perchlorate in all the samples were less than 1, suggesting negligible health risks caused by these pollutants from tea consumption. To the best of our knowledge, this is the first study to investigate chlorate and perchlorate contamination in tea infusions by simulating brewing behavior.

Establishment of an Integrated Nontarget and Suspect Screening Workflow for Organophosphate Diesters (Di-OPEs) and Identification of Seven Previously Unknown Di-OPEs in Food Contact Plastics.

In this study, an innovative, integrated nontarget and suspect screening workflow was developed for identifying organophosphate diesters (di-OPEs) using high-resolution mass spectrometry. The workflow featured the utilization of 0.02% acetic acid as a mobile-phase additive, differentiated screening methods for alkyl and aryl di-OPEs, and a combination of electrospray negative ionization and positive ionization. Using this workflow, 18 di-OPEs were identified in the extracts of 75 food contact plastic (FCP) samples sourced from South China. Among these, six alkyl and one aryl di-OPEs were previously unknown (one unequivocal identification and six probable structures based on diagnostic evidence). (Semi)quantification revealed that bis(2,4-di-tert-butylphenyl) phosphate was the major di-OPE in FCPs, with a median concentration of 1079 ng/g (range: 23.4-158,414 ng/g). The migration efficiencies of di-OPEs from an FCP sample to four kinds of food simulants were between 2.58 and 54.3%. This study offered a useful workflow for the comprehensive profiling of di-OPEs in FCPs.

Nitroaromatic Compounds from Secondary Nitrate Formation and Biomass Burning Are Major Proinflammatory Components in Organic Aerosols in Guangzhou: A Bioassay Combining High-Resolution Mass Spectrometry Analysis.

The limited characterization and detection capacity of unknown compounds hinder our understanding of the molecular composition of toxic compounds in PM2.5. The present study applied Fourier transform ion cyclotron resonance mass spectrometry coupled with negative and positive electrospray ionization sources (ESI-/ESI+ FT-ICR-MS) to probe the molecular characteristics and dynamic formation processes of the effective proinflammatory components in organic aerosols (OAs) of PM2.5 in Guangzhou for one year. We detected abundant proinflammatory molecules in OAs, mainly classified as CHON compounds (compounds composed of C, H, O, and N atoms) in elemental and nitroaromatic compounds (NACs) in structures. From the perspective of the formation process, we discovered that these proinflammatory molecules, especially toxic NACs, were largely driven by secondary nitrate formation and biomass burning (in emission source), as well as SO2 (in atmospheric evolution). In addition, our results indicated that the secondary processes had replaced the primary emission as the main contributing source of the toxic proinflammatory compounds in OAs. This study highlights the importance of community measures to control the production of nitroaromatic compounds derived from secondary nitrate formation and biomass burning in urban areas.

Temporal and spatial distributions, source identification, and health risk assessment of polycyclic aromatic hydrocarbons in PM2.5 from 2016 to 2021 in Shenzhen, China.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in the atmosphere that have drawn intense attention due to their carcinogenicity and mutagenicity. In this work, 1424 air samples were collected between January 2016 and December 2021 in three areas of Shenzhen, China to determine the concentrations of PM2.5 and PAHs and their spatiotemporal variation. Human health risks due to the daily intake and uptake of PAHs and the resulting incremental lifetime cancer risk (ILCR) were also evaluated. PAHs were detected frequently in the samples at concentrations between 0.28 and 32.7 ng/m3 (median: 1.04 ng/m3). PM2.5 and PAH concentrations decreased from 2016 to 2021, and the Yantian area had lower median concentrations of PM2.5 (23.0 µg/m3) and PAHs (0.02 ng/m3) than the Longgang and Nanshan areas. The concentrations of PM2.5 and PAHs were significantly higher in winter than in summer. Analysis of diagnostic ratios indicated that petroleum combustion was the dominant source of airborne PAHs in Shenzhen. The estimated daily intake (EDI) and uptake (EDU) of PAHs by local residents decreased gradually with increasing age, indicating that infants are at particular risk of PAH exposure. However, the incremental lifetime cancer risks (ILCRs) were below the threshold value of 10-6, indicating that inhalation exposure to PAHs posed a negligible carcinogenic risk to Shenzhen residents. While promising, these results may underestimate actual PAH exposure levels, so further analysis of health risks due to PAHs in Shenzhen is needed.

High-resolution mass spectrometry-based screening and dietary intake assessment of organophosphate esters in foodstuffs from South China.

Organophosphate esters (OPEs) are a group of emerging contaminants with widespread environmental occurrence, yet research on their occurrence in foodstuffs is limited. We collected 100 foodstuff samples in South China using a market basket method, and analyzed food extracts for the presence of OPEs and organophosphite antioxidants (OPAs) by suspect and nontarget screening through high-resolution mass spectrometry. Our analysis resulted in the identification of 30 OPEs, comprised of 25 OPEs with a confidence level (CL) of 1 (unequivocal identification using standards) and five OPEs with CL = 2b (probable structure based on diagnostic evidence). Interestingly, 11 of these identified OPEs had not been previously reported in food. No OPA was identified. The occurrence of identified OPEs within the food samples was further investigated. The highest median concentration of OPEs in all food samples was reached by tris(2-chloroisopropyl) phosphate (TCPP) (1.55 ng/g ww, range < 0.74-12.0 ng/g wet weight (ww)). Cereals demonstrated the highest median concentration of the cumulative 30 OPEs. Tris(2-chloroethyl) phosphate (TCEP), TCPP, and triethyl phosphate (TEP) predominantly contributed to OPEs contamination in most food categories. Eight OPEs, namely TEP, tris(2-ethylhexyl) phosphate (TEHP), TCEP, triphenyl phosphate (TPhP), 2-ethylhexyl diphenyl phosphate (EHDPP), bis(2-ethylhexyl) phenyl phosphate (BEHPP), resorcinol bis(diphenyl phosphate) (RDP), and methyl diphenyl phosphate (MDPP) exhibited significantly higher concentrations in the processed group as compared to non-processed group, suggesting that food processing may result in contamination of these OPEs. The median sum of estimated dietary intake (ΣEDI) of all OPEs was determined to be 161 ng/kg body weight/day. Cereals (38.5 %) and vegetables (23.5 %) were the predominant food categories contributing to ΣEDI, and TEP (29.0 %), TCEP (20.2 %), and TCPP (18.3 %) were three major OPEs contributing to ΣEDI. This study for the first time offered a comprehensive overview of OPE species and revealed their occurrence in foodstuffs from South China.

Neonicotinoids in tea leaves and infusions from China: Implications for human exposure.

The ingestion of contaminated tea involves the risk of human exposure to residues of neonicotinoids (NEOs). Nevertheless, there is little empirical research about this topic; to bridge the current knowledge gap, we collected 220 samples of various tea products from four geographical areas in China, including unfermented green tea, semi-fermented white tea and oolong tea, completely fermented black tea, and post-fermented dark tea. A total of six NEOs were detected from the tea leaves and infusions, namely, dinotefuran (DIN), thiamethoxam (THM), clothianidin (CLO), imidacloprid (IMI), acetamiprid (ACE), and thiacloprid (THI). The detection frequencies (DFs) and concentrations of all target NEOs were relatively high across the investigated tea samples, and the DIN, IMI and ACE residues measured in some samples exceeded the maximum residue level (MRL) standards for the European Union. Samples representing the Jiangnan area exhibited greater levels of total target NEOs (∑6NEOs) than samples representing the Jiangbei area (p < 0.001). Moreover, dark tea samples were found to have far higher levels of NEO residues than green (p < 0.001), white (p < 0.05), or oolong (p < 0.001) samples. The health risks associated with exposure to NEO residues via tea were small for both children and adults in terms of acute, chronic, and cumulative dietary exposure risk assessments. The transfer rates (TRs) of NEOs observed in white, black, and dark tea infusions gradually decreased after the third brewing time. As such, it is recommended to only consume tea that has been brewed at least three times. The presented results not only describe the extent of NEO contamination in Chinese tea leaves and infusions, but also provide tea drinking guidelines for consumers.

Urinary essential and toxic metal mixtures, and type 2 diabetes mellitus: Telomere shortening as an intermediary factor?

The joint effect of metal mixtures on telomere function and type 2 diabetes mellitus (T2DM) is unclear. This large-scale cross-sectional study sought to assess the role of telomere length (TL) in the relationship between urinary essential and toxic metal mixtures, and T2DM in 7410 Chinese adults ≥ 60 years of age. Essential (Cr, Cu, Zn, Se) and non-essential metals (V, Al, Sb, Sn, Cd, Pb) in urine samples were quantified, while leukocyte TL was measured from blood samples. Restricted cubic splines regression showed nonlinear relationships between single metal and T2DM, and between TL and T2DM. Bayesian kernel machine regression and quantile-based g-computation showed that the overall status of urinary metals was positively associated with risk of developing T2DM, which was mainly explained by exposure to Pb, Cd, and Sb, excessive Se intake, and high excretion of Zn. Mediation analyses showed that shortened TL mediated 27.9% of the overall positive effect of metal exposure on T2DM, and this mediation was mainly explained by toxic metal exposure and excessive Se intake. Tobacco smoke exposure, extensive cooking at home, and black tea consumption were found to be important contributors of toxic metal exposures. Further studies are needed to explore the recommended Zn dosage for T2DM patients at different stages, which may ameliorate pancreatic senescence and glycemic progression.

Within-person variability of urinary neonicotinoids and their metabolites and recommendation for sampling strategy.

Humans are exposed to neonicotinoid insecticides (NEOs) from various routes. Urine has been widely used to characterize the internal exposure levels of NEOs in humans. However, variable sampling methods can result in highly variable measurements of NEOs, potentially leading to misunderstanding of human exposure. In this study, we collected the first morning voids urine (FMVU), spot urine (SU), and 24 h urine (24hU) samples from 8 healthy adults during 7 consecutive days. The concentration, variability, and reproducibility of six parent NEOs (p-NEOs) and three NEOs metabolites (m-NEOs) were measured. Over 79 % of the urine samples had detectable levels of NEOs. Dinotefuran (DIN) and olefin-imidacloprid (of-IMI) were excreted in the highest concentration of p-NEO and m-NEO, respectively. All of the p-NEOs except thiacloprid (THD) and of-IMI were recommended as biomarkers for biomonitoring studies. The coefficient of variation (CV) and intraclass correlation coefficient (ICC) were used to evaluate the temporal variability and reproducibility of urinary NEOs in SU, FMVU and 24hU, respectively. We observed low ICCs ranging from 0.016 to 0.39 for NEOs regardless of the sample types. However, the higher CV and lower ICC values observed in SU samples suggested lower reproducibility compared to FMVU and 24hU samples. Significant correlations of several NEOs between FMVU and 24hU were also observed in the current study. Considering the comparable concentrations and similarity between FMVU and 24hU, our study proposed possible biomarkers and indicated that the potential for FMVU samples to estimate adequately an individual's exposure to NEOs. Therefore, we suggested FMVU as a sampling strategy in future human biomonitoring studies, while multiple samples were recommended to detect exposure over time intervals of weeks or months.

A nationwide investigation of trace elements in rice and wheat flour in China: Levels, spatial distributions and implications for human exposure.

Rises in trace element contents in rice and wheat flour, which are staple foods for almost all the Chinese population, associated with rapid economic development have raised major concerns. This study aimed to assess trace element concentrations in these foods nationwide in China and associated human exposure risks. For these purposes, nine trace elements were measured in 260 rice samples and 181 wheat flour samples with 17 and 12 widely scattered geographical origins in China, respectively. Mean concentrations (mg kg-1) of the trace elements declined in the following orders: Zn > Cu > Ni > Pb > As > Cr > Cd > Se > Co in rice, and Zn > Cu > Ni > Se > Pb > Cr > Cd > As > Co in wheat flour. Significant regional differences in levels of trace elements in both rice and wheat flour were detected (p < 0.05), which may be related to local economic indicators. The hazard index (HI) of trace elements in rice samples from all origins exceeded 1, mainly due to the contribution of As, suggesting a potential non-carcinogenic risk. The total carcinogenic risk (TCR) for rice and wheat flour of all origins exceeded the safe level.

Co-exposure to parabens and triclosan and associations with cognitive impairment in an elderly population from Shenzhen, China.

Parabens and triclosan (TCS) have been extensively applied in personal care products (PCPs) as preservatives and antibacterial agents. However, their potentiality to disrupt the neurological system has induced increasing concern. The elderly population is at a higher risk of neurodegenerative disorder, although research on its association with PCP exposure remains scarce. Here, we measured the urinary levels of four parabens, TCS, and an oxidative stress marker among 540 participants from the Shenzhen aging-related disorder cohort during 2017-2018. The Mini-Mental State Examination (MMSE) was used to assess the cognitive status of participants. Their demographic, dietary, and behavioral factors were collected via questionnaire survey. Among the four paraben analogs, the median concentration of methyl parabens (MeP) was the highest (Low-risk group: 1.21 ng/mL, High-risk group: 1.64 ng/mL). TCS and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were detected in more than 90% of the samples. Weighted quantile sum regression and quantile-based g-computation showed that the combined effect of all analytes was positively associated with the level of 8-OHdG. BtP, EtP and MeP were identified as the major contributors to the joint effect. After stratification by gender, females exhibited more pronounced changes in urinary 8-OHdG level than males. However, the positive correlation between co-exposure to parabens and TCS and cognitive impairment was not significant (p > 0.05) in both models, which warrants investigation with the larger sample size.

Trace elements in aquatic products from Shenzhen, China and their implications for human exposure.

Aquatic organisms in industrially polluted areas can accumulate large quantities of heavy metals. To assess the resulting health risks, 11 trace elements in 184 aquatic products representing 14 species of fish, crustaceans, and bivalves collected from Shenzhen, China were determined. Aluminum (Al), chromium (Cr), nickel (Ni), selenium (Se), antimony (Sb), manganese (Mn), copper (Cu), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were determined by inductively coupled plasma mass spectrometry. The pollution levels of each product and the human health risk resulting from their consumption were then assessed. The concentrations of As in 57 % of samples and Cd in 11 % of samples exceeded the upper limits stipulated by the Chinese National Food Safety Standards (GB 2762-2017), which was mainly due to high concentrations of trace elements in crustaceans and bivalves. The Nemerow integrated pollution index indicated that the aquatic products accumulated high levels of As and Cd. Health risk assessments using the target hazard quotient (THQ) and hazard index (HI) suggested that As and Cd exposure due to consumption of aquatic products presents a potential health risk for residents of Shenzhen.

Infantile Internal and External Exposure to Neonicotinoid Insecticides: A Comparison of Levels across Various Sources.

Little is known about exposure of infants to neonicotinoid insecticides (NEOs). In this study, concentrations of six parent NEOs (p-NEOs) and N-desmethyl-acetamiprid (N-dm-ACE) were measured in urine and whole blood samples from infants, in addition to breast milk, infant formula, and tap water collected in South China. The p-NEO with the highest median concentration in urine (0.25 ng/mL) and blood (1.30) samples was dinotefuran (DIN), while imidacloprid (IMI) was abundant in breast milk (median: 0.27 ng/mL), infant formula (0.22), and tap water (0.028). The older infants (181-360 days) might face higher NEO and N-dm-ACE exposure than younger infants (0-180 days). Blood samples contained a significantly (p < 0.01) higher median concentration of ∑6p-NEOs (2.03 ng/mL) than that of urine samples (0.41), similar to acetamiprid (ACE), IMI, thiacloprid (THD), DIN, and N-dm-ACE, suggesting that NEOs readily partition into blood. Furthermore, breast-fed infants tend to have higher exposure levels than formula-fed infants. Infant formula prepared with tap water augmented the daily intake of ∑NEOs. The external sources contributed 80% of the total dose to IMI and clothianidin (CLO) exposure, while other unknown sources contributed to ACE, THD, and DIN exposure in infants. To the best of our knowledge, this is the first study to assess levels and sources of infantile exposure to NEOs through internal and external exposure assessment.