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.

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.

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.

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.

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.

A holistic review on triclosan and triclocarban exposure: Epidemiological outcomes, antibiotic resistance, and health risk assessment.

Triclosan (TCS) and triclocarban (TCC) are antimicrobials that are widely applied in personal care products, textiles, and plastics. TCS and TCC exposure at low doses may disturb hormone levels and even facilitate bacterial resistance to antibiotics. In the post-coronavirus disease pandemic era, chronic health effects and the spread of antibiotic resistance genes associated with TCS and TCC exposure represent an increasing concern. This study sought to screen and review the exposure levels and sources and changes after the onset of the coronavirus disease (COVID-19) pandemic, potential health outcomes, bacterial resistance and cross-resistance, and health risk assessment tools associated with TCS and TCC exposure. Daily use of antimicrobial products accounts for most observed associations between internal exposure and diseases, while secondary exposure at trace levels mainly lead to the spread of antibiotic resistance genes. The roles of altered gut microbiota in multi-system toxicities warrant further attention. Sublethal dose of TCC selects ARGs without obviously increasing tolerance to TCC. But TCS induce persistent TCS resistance and reversibly select antibiotic resistance, which highlights the benefits of minimizing its use. To derive reference doses (RfDs) for humans, more sensitive endpoints observed in populational studies need to be confirmed using toxicological tests. Additionally, the human equivalent dose is recommended to be incorporated into the health risk assessment to reduce uncertainty of extrapolation.

Risk assessment of metal(loid)s in tea from seven producing provinces in China.

To evaluate metal(loid) contamination in tea leaves and assess health risks of tea drinking in China, metal(loid) concentrations in tea leaves from major tea-producing provinces were determined. Nine metal(loid)s (Al, Cr, Co, Ni, Cu, Zn, As, Cd and Pb) were measured in a total of 217 tea samples representing five tea varieties (black tea, dark tea, green tea, oolong tea and white tea) from seven major tea-producing provinces of China (Fujian, Guangdong, Henan, Hunan, Jiangsu, Yunnan and Zhejiang). The results indicated that tea samples from Hunan Province had the highest metal(loid) concentrations, likely due its high prevalence of heavy industrial activities and soil pollution. The concentrations of As and Pb in dark tea were markedly higher than those in other tea varieties. A strong Spearman correlation coefficient (0.78, P < 0.001) of As and Pb in all the tea varieties has also been found, indicating their similar sources. Human health risk assessment for the nine analyzed metal(loid)s indicated that co-exposure to these metal(loids) may not cause significant health risks (hazard index [HI] > 1 suggests considerable health risks). Among the five tea varieties, metal(loids)s in dark and green tea induced relatively higher health risks, with 90th percentile HI values approached 0.8. Co (53.6 %-84.5 %) and Al (3.33 %-15.8 %) made the highest contributions to the HI of the selected tea commodities. Thus, public and regulatory agencies should reduce excessive Co and Al accumulation in these tea varieties during cultivation and production processes.

Organophosphate ester exposure among Chinese waste incinerator workers: Urinary levels, risk assessment and associations with oxidative stress.

Organophosphate esters (OPEs), which are frequently used as flame retardants and plasticizers in versatile products, are readily released to the external environment. Although workers at municipal waste incineration plants may be extensively exposed to OPEs, only scarce health monitoring and risk assessments have been conducted in this population. In this study, we investigated the levels of eight metabolites of organophosphate esters (mOPEs) and the oxidative stress marker 8-hydroxy-2-deoxyguanosine (8-OHdG) in urine samples from 73 waste incinerator workers and 97 general residents from Shenzhen, China between September 2016 and June 2017. The overall detection rate of mOPEs was 82.2 %-100 %, and higher concentrations of di-p-cresyl phosphate and chlorinated mOPEs [bis(2-chloroethyl) phosphate (BCEP), bis(1-chloro-2propyl) phosphate (BCIPP), bis(1,3-dichloro-2-propyl) phosphate) (BDCIPP)] were found among incinerator workers than among general residents. The incinerator workers also showed significantly higher levels of 8-OHdG than general residents, but the measured levels of most mOPEs were not significantly correlated with the level of 8-OHdG; this may be because co-exposure to multiple toxic compounds can lead to oxidative stress. Risk assessment using Monte Carlo simulations revealed that 95 % of the incinerator workers were free from non-carcinogenic effects due to OPEs exposure (hazard index = 0.27, 95 % CI: 0.09, 0.77). However, the carcinogenic risk of tris(2-chloroethyl) phosphate (TCEP) for incinerator workers was between 10-6 and 10-4. These results indicate that incinerator workers are extensively exposed to OPEs, and better protective measures need to be implemented.

A nationwide investigation of perchlorate levels in staple foods from China: Implications for human exposure and risk assessment.

Perchlorate is an emerging pollutant and thyroid toxicant frequently occurred in air, water, soil and various foodstuffs. Rice and wheat flour are the most common staple foods, which could accumulate perchlorate from contaminated soils and irrigation water. However, human exposure to perchlorate via rice and wheat flour consumption has only been investigated to a limited extent. Therefore, we collected 207 rice samples and 189 wheat flour samples from 19 provinces in China to assess the level of perchlorate. The levels of perchlorate in rice and wheat flour ranged from not detected (N.D.) to 28.7 ng/g and less than limits of quantification (

Health risk assessment of perchlorate and chlorate in red swamp crayfish (Procambarus clarkii) in China.

Perchlorate and chlorate are both strong oxidants and thyroid toxicants that are widely distributed in soil, water and human foods. The red swamp crayfish (Procambarus clarkii) is a common aquatic organism that is popular in Chinese culinary dishes. Dietary intake is the main route of human exposure to perchlorate and chlorate, though the health risks of crayfish consumption are unknown. Thus, this study investigated the quantities of perchlorate and chlorate in red swap crayfish from sampling sites in five provinces located near the Yangtze River in China, along with the associated health risks of consuming this species. Perchlorate was detected in 55.6-100 % of crayfish samples in each sampling location, and chlorate was found in 100 % of samples cross all sites. Concentrations of perchlorate in crayfish from upstream provinces (Hubei, Hunan and Jiangxi) were higher than those from downstream provinces (Anhui and Jiangsu). Perchlorate and chlorate concentrations were positively correlated in crayfish, suggesting that chlorate may be a degradation byproduct of perchlorate. The quantities of both pollutants in hepatopancreas tissue were higher than in muscle tissues (p < 0.05), such that we do not recommend ingesting crayfish hepatopancreas. Hazard quotient (HQ) values for chlorate in crayfish were <1 across all provinces, suggesting no potential health risk of chlorate exposure through crayfish consumption. However, perchlorate concentrations in crayfish from the Jiangxi province had an associated HQ value >1, suggesting potential risks for human health. These results will be useful in informing mitigation measures aimed at reducing perchlorate exposure associated with crayfish consumption.

Arsenic speciation in shellfish from South China Sea: Levels, estimated daily intake and health risk assessment.

The purposes of this study were to measure the concentrations of arsenic speciation in shellfish from South China Sea and evaluate the health risk by local residents through shellfish consumption. The median concentrations (in wet weight) of arsenic speciation in shellfish samples were in the following order: AsB (16.0 mg·kg-1) > DMA (1.30 mg·kg-1) > AsV (0.23 mg·kg-1) > AsC (0.08 mg·kg-1) > AsIII (0.05 mg·kg-1) > MMA (0.01 mg·kg-1). Among shellfish species, Mactra mera and Babylonia areolata were found to accumulate iAs and AsB, respectively. The target hazard quotient values of iAs (THQiAs) in all shellfish samples were lower than 1. However, the carcinogenic risk values of iAs (CRiAs) in the Mactra mera, Mytilus galloprovincialis and Pinctada margaritifera were beyond the acceptable range, implying that continuous exposure to iAs pollution via the consumption of these shellfish would pose a potential cancer risk to local consumers.

Interrelationship of anthropogenic activity and parabens in fish from Taihu Lake during 2009-2017.

Parabens are alkyl esters widely used as preservatives in foodstuffs, cosmetics, and pharmaceuticals. Taihu Lake is the third largest freshwater lake in China. However, there is no information available on the occurrence of parabens in Taihu Lake. To investigate contamination of parabens in Taihu Lake and the influence of human activities on contamination levels, 199 fish samples, comprising five species, were collected from Taihu Lake from 2009 to 2017. Five parabens, including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP), and benzylparaben (BeP), were quantitated using an isotope dilution LC-MS/MS method. The total concentrations of the five parabens ranged from 261 to 1710 pg/g wet weight (ww) with an average of 642 pg/g ww. The predominant compounds were MeP, EtP, and PrP, whose amounts accounted for more than 95% of the total amounts. No significant differences in the concentrations of parabens among the five fish species were observed, suggesting no interspecies differences in bioaccumulation of these compounds. Σ5parabens in fish showed temporal variations with the means ranging between 532 and 772 pg/g ww during years. The levels of parabens were generally consistent with the economic development and urbanization rates of the regions surrounding Taihu Lake. The "typical" and "high" estimated daily intake (EDI) of parabens were 0.53 and 0.91 ng/kg-bw/day for children, and 0.46 and 0.79 ng/kg-bw/day for adults based on calculations using the means and the 95th concentrations, respectively. The EDIs were much lower than the reference dose values, suggesting that there are no obvious health risks posed by fish consumption.

Benzophenone-UV filters in personal care products and urine of schoolchildren from Shenzhen, China: Exposure assessment and possible source.

The use of benzophenone (BP)-type UV filters in personal care products (PCPs) has rapidly increased in China over the past decade, leading to growing concerns on the potential adverse effects associated with the usage. Urine analysis is an ideal non-invasive approach for human biomonitoring of xenobiotics that are excreted mainly through urinary system. To investigate human exposure of PCPs to children from South China, we determined BP-type UV filters in a total of 156 commercial PCP goods covering 11 categories, as well as 280 urine samples collected from elementary school students in Shenzhen, China. Five BP analogues (i.e., BP1, BP2, BP3, BP8, and 4HB) were frequently detected in both PCPs and urine, among which BP3 was the dominant analogue, accounting for 96.3% of the total BPs in PCPs and 53.2% in urine, respectively. Sunscreens contained the highest BP concentrations (mean: 2.15 × 104 ng g-1) among all PCP goods. Girls exhibited higher urinary BP concentrations than boys, and body mass index positively influenced BP concentrations. However, no regional difference in urinary BP concentration was observed. The estimated dermal uptake of BPs from PCPs after considering the percutaneous absorption rates was much lower than the estimated dermal intake. The total daily excretion doses estimated from urinary BPs were 74.4 and 47.4 ng·kg-1bw day-1 for girls and boys, respectively. The higher usage of body lotions, hand lotions, and sunscreens by girls than boys (1.49 vs. 1.03 times week-1) might play an important role.

Phthalates in PM2.5 from Shenzhen, China and human exposure assessment factored their bioaccessibility in lung.

Temporal variability of phthalates (PAEs) in PM2.5 from Shenzhen during 2015-2016 was measured and the associated human exposure via inhalation was assessed. The PM2.5 concentrations ranged from 30.7 to 115 µg m-3, greater than the air quality guidelines of interim target-3 (10-15 µg m-3) and interim target-2 (15-25 µg m-3) set by World Health Organization. PAEs were detected in 94.7% samples and the 95th percentile concentrations of total PAEs (∑6PAEs) in Longgang and Nanshan districts were 324 and 44.7 ng m-3, respectively. Di-2-ethylhexyl phthalate was the dominant species, accounting for an average of 81.9% of ∑6PAEs. The mean and 95th percentile concentrations of ∑6PAEs in PM2.5 were used to calculate a "typical" and "high" total daily intake and uptake, respectively. The estimated total daily intakes of PAEs varied and depended on body weight in each age group. Infants had the highest "typical" and "high" daily intake of 43.4 and 179 ng kg-body weight (bw) -1 day-1 for boys, and 42.0 and 173 ng kg-bw-1 day-1 for girls, respectively. However, after taking the bioaccessibility of PAEs in PM2.5 into account, the total daily "typical" and "high" uptakes dropped to 27.3 and 113 ng kg-bw-1 day-1 for male infants, and 29.0 and 120 ng kg-bw-1 day-1 for female infants, respectively. Both of the data on the daily "high" intake and uptake were much lower than the tolerable daily intake set by the European Food Safety Agency. It merits attention that infants were subject to greater PAE exposure than adults.

Toxaphene levels in retail food from the Pearl River Delta area of South China and an assessment of dietary intake.

Limited literature exists on toxaphene contamination in food worldwide, particularly in mainland China. In this study, three toxaphene congeners, Parlar 26 (B8-1413), Parlar 50 (B9-1679) and Parlar 62 (B9-1025), were analyzed in five different food categories from the Pearl River Delta Area in China using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS), and toxaphene levels in food were reported and toxaphene dietary intake by local residents estimated. The results showed that fish contained the highest toxaphene level with a median of 12.87 pg/g wet weight (ww), followed by poultry meat, egg products, livestock meat and vegetable, which had median levels of 5.8, 2.2, 1.89 and 0.67 pg/g ww, respectively. Parlar 50 and Parlar 26 were the predominant characteristic congeners in fish, and Parlar 26 was the predominant congener not only in poultry products and eggs, but also in livestock and vegetable. The estimated average daily intake found by local residents was 35.57 pg/kg body weight/day. Overall toxaphene levels and estimated dietary intake in the Pearl River Delta Area of South China are far lower than the European Maximum Residue Limits (EU MRLs), the German MRL for fish, and other international literature data. Therefore, the risk of adverse health effects from dietary intakes of toxaphene for the local residents is not considerable at the current time, but follow-ups are warranted to study dynamic changes of toxaphene in food in this area.

Concentrations and health risk assessment of trace elements in animal-derived food in southern China.

This study aimed to investigate the levels of trace elements in animal-derived food in Shenzhen, Southern China. The concentrations of 14 trace elements (Cd, Hg, Pb, As, Cr, Cu, Fe, Zn, Mn, Mo, Ni, Co, Se and Ti) in a total of 220 meat samples, collected from the local markets of Shenzhen were determined. Cu, Fe and Zn were the major elements, with concentrations approximately 2-3 orders of magnitude higher than those of other elements. However, the daily intakes of Cu, Fe and Zn merely via the consumption of the meat products were lower than the recommended nutrient intake values provided by the 2013 Chinese Dietary Guide. Among the non-essential trace elements, Cd was accumulated in animal viscera, and the concentration ratios of chicken gizzard/chicken, chicken liver/chicken, pig kidney/pork and pig liver/pork were 41.6, 55.2, 863 and 177, respectively. In addition, high concentrations of As were found in aquatic products, especially in marine fish. The concentration of As in marine fish was slightly higher than the limits recommended by China, USA and Croatia. The health risk assessment of trace elements through the consumption of meat products by adult residents in Shenzhen was evaluated by using the target hazard quotient (THQ) method. The total THQ was greater than 1, implying a potential health risk. Approximately 66% of total THQ values, mainly from As, were from the consumption of aquatic products.

[Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans in airborne fine particulate matter and inhalation risk assessment for local residents of Shenzhen].

OBJECTIVE: To explore the levels and congener profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in airborne fine particulate matter (PM25) in Shenzhen and roughly discuss its correlations between PM25 concentration and meteorological factors. METHODS: The high volume air samplers were used to collect the samples in six sampling sites in respective winter and spring phase and summer and autumn phase. Referring to the US EPA TO-9A for dioxins detection methods, the concentrations of the 17 polychlorinated dibenzo-p-dioxins and dibenzofurans in airborne fine particulate matter were determined by HRGC/HRMS. RESULTS: The total concentrations of PCDD/Fs ranged from 0.32 to 9.35 pg/m3, with average of 2.45 pg/ m3. The TEQ concentrations ranged from 0.006 to 0.388 pg I-TEQ/m3, with average of 0.095 pg I-TEQ/m3. The four abundant congeners were found to be OCDD (36.49%), 1, 2, 3, 4, 6, 7, 8-HpCDF (14.89%), OCDF (13.34%) and 1, 2, 3, 4, 6, 7, 8-HpCDD (10.92%). 2, 3, 4, 7, 8-PeCDF was the dominant contributor to toxicity equivalent (TEQ), accounting for 34.65%. Positive relationship was found between the levels of fine particle-bound PCDD/Fs and PM2.5 concentration (r(s) = 0.794, P = 0.006), whereas no correlation was observed for temperature, humidity and atmospheric pressure. Inhalation exposure to PCDD/Fs were 0. 023 pg I-TEQ/(kg · d) for adult and 0.035 pg I-TEQ/(kg · d) for children during winter and spring and relatively higher than those during summer and autumn (0.014 pg I-TEQ/(kg · d). for adult and 0.021 pg I-TEQ/(kg · d) for children respectively). CONCLUSION: The levels of PCDD/Fs in airborne fine particle-bound samples collected in Shenzhen were lower than those in Hangzhou and Beijing.

Trace elements contamination and human health risk assessment in drinking water from Shenzhen, China.

The levels of seven essential trace elements (Mn, Co, Ni, Cu, Zn, Se, and Mo) and six non-essential trace elements (Cr, As, Cd, Sb, Hg, and Pb) in a total of 89 drinking water samples collected in Shenzhen, China were determined using inductively coupled plasma mass spectrometry (ICP-MS) in the present study. Both the essential and non-essential trace elements were frequently detectable in the different kinds of drinking waters assessed. Remarkable temporal and spatial variations were observed among most of the trace elements in the tap water collected from two tap water treatment plants. Meanwhile, potential human health risk from these non-essential trace elements in the drinking water for local residents was also assessed. The median values of cancer risks associated with exposure to carcinogenic metals via drinking water consumption were estimated to be 6.1 × 10(-7), 2.1 × 10(-8), and 2.5 × 10(-7) for As, Cd, and Cr, respectively; the median values of incremental lifetime for non-cancer risks were estimated to be 6.1 × 10(-6), 4.4 × 10(-5), and 2.2 × 10(-5) for Hg, Pb, and Sb, respectively. The median value of total incremental lifetime health risk induced by the six non-essential trace elements for the population was 3.5 × 10(-5), indicating that the potential health risks from non-carcinogenic trace elements in drinking water also require some attention. Sensitivity analysis indicates that the most important factor for health risk assessment should be the levels of heavy metal in drinking water.

The arsenic contamination of rice in Guangdong Province, the most economically dynamic provinces of China: arsenic speciation and its potential health risk.

Rice is a staple food in China, but it may contain toxic heavy metals. Hence, the concentrations of arsenic (As) species (As(III), As(V), MMA and DMA) were evaluated in 260 rice samples from 13 cities of Guangdong Province, the most economically dynamic provinces of China. The levels of sum concentrations of As species in rice samples varied from non-detect to 225.58 ng g(-1), with an average value of 57.27 ng g(-1). The mean concentrations of the major As species detected in rice samples were in the order As(III) (34.77 ng g(-1)) > As(V) (9.34 ng g(-1)) > DMA (8.33 ng g(-1)) > MMA (4.82 ng g(-1)). The rice samples of Guangdong Province were categorized as inorganic As type. Significant geographical variation of As speciation existed in rice samples of 13 cities of Guangdong Province by chi-square test (p < 0.05). The average human weekly intakes of inorganic As via rice consumption in Guangdong Province, southern China, were 1.91 µg kg(-1) body weight. Hazard quotients of total As via rice consumption of adults in 13 cities ranged from 0.06 to 0.30, indicating the As contents in rice from Guangdong Province had no potential adverse impact on human health.