A pilot study of several environmental endocrine disrupting chemicals in children with autism spectrum disorder in south China.

Autism spectrum disorders (ASD) is a group of heterogeneous neurodevelopmental disorders. Evidence has implied that environmental pollutants are important factors related to ASD. In this study, several environmental endocrine-disrupting chemicals, including parabens, benzophenone-type ultraviolet filters, hydroxyl polycyclic aromatic hydrocarbons, triclosan and tetrabromobisphenol A were analyzed in blood plasma in ASD children (n = 34) and the control children (n = 28). The results showed that parabens were the most concentrated chemicals (2.18 ng/mL, median value), followed by hydroxyl polycyclic aromatic hydrocarbons (0.73 ng/mL), benzophenone-type ultraviolet filters (0.14 ng/mL), triclosan (0.13 ng/mL) and tetrabromobisphenol A (0.03 ng/mL). ASD children accumulated significantly lower 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 4-hydroxybenzophenone and triclosan but higher 2-hydroxyphenanthrene and tetrabromobisphenol A than the control children (0.02/0.09 ng/mL of 2-hydroxy-4-methoxybenzophenone, p < 0.05; 0.04/0.07 ng/mL of 2,4-dihydroxybenzophenone, p < 0.05; 0.03/0.04 ng/mL of 4-hydroxybenzophenone, p < 0.05; 0.13/1.22 ng/mL of triclosan, p < 0.01; 0.03 ng/mL/not detected of 2-hydroxyphenanthrene, p < 0.05; 0.03/0.004 ng/mL of tetrabromobisphenol A, p < 0.05). Gender differences in certain environmental endocrine-disrupting chemicals were evident, and the differences were more inclined toward boys. Positive associations between 2-hydroxy-4-methoxybenzophenone and triclosan, and tetrabromobisphenol A and 2-hydroxyphenanthrene were found in ASD boys. Binary logistic regression analysis showed that the adjusted odds ratio value of 2-hydroxyphenanthrene in ASD boys was 11.0 (1.45-84.0, p < 0.05). This is the first pilot study on multiple environmental endocrine-disrupting chemicals in children with ASD in China.

Feminine Hygiene Products-A Neglected Source of Phthalate Exposure in Women.

Phthalates have been associated with reproductive toxicity and precocious puberty in females, but the occurrence of these toxicants in feminine hygiene products is rarely reported. In this study, eight phthalates were determined in 120 feminine hygiene products (56 feminine care products and 64 sanitary napkins) collected from China. Phthalates were found in 86% and 98% of feminine care products and sanitary napkins, respectively, with the total concentrations varying between not detectable and 813 µg/g (median: 0.26 µg/g) and 0.25 and 8.76 µg/g (1.43 µg/g), respectively. Diethyl phthalate, dibutyl phthalate, and bis(2-ethylhexyl)phthalate were the major compounds, accounting for >60% of the total concentrations. The plastic materials used on the top and bottom layers and the hot melt adhesive used during the manufacturing process are the potential sources of phthalates in sanitary napkins. The range of daily exposure doses of phthalates in women from the use of feminine care products and sanitary napkins was <0.001-0.156 µg/kg-bw/day and <0.001-0.731 µg/kg-bw/day, respectively. Sanitary napkins contributed to 8.2% of the total exposure, and the levels of exposure to several phthalates from sanitary napkins were much higher than those reported from indoor dust ingestion but were lower than those of dietary intakes. Our study confirmed a new source of women's exposure to phthalates, sanitary napkins.

Triclosan in over the counter medicines of South China.

Triclosan (TCS) is an endocrine disruptor which may affect endocrine function, antibiotic resistance, and thyroid hormone homeostasis. As a broad-spectrum antimicrobial agent used in medical and personal care products, TCS was frequently detected in human urine, indicating widespread human exposure to this chemical. Over-the-counter medicines (OTCs) may be a potential source of human exposure to TCS. In this study, 84 OTCs were collected from Guangzhou, South China, including medicines intended for both children and adults. We determined the concentration of TCS in OTCs and the estimated daily intakes (EDIs) of TCS by evaluating OTCs for different age groups of the Chinese population. Our results indicated over half of the evaluated medicines contained TCS and the highest concentration reached 7.825 ng/g, with a median value of 0.017 ng/g. TCS was frequently found in adult medicines (detected in 85% of samples), and the concentrations were significantly higher than those in children's medicines. TCS in OTCs may come from packaging materials, cultivated soils, or production process (Chinese patent medicines). The EDIs of TCS (estimated with 95th concentration in OTC medicines) were 0.305, 0.191, 0.287, 0.331, and 0.135 and 0.110 ng/kg-bw/day for infants, toddlers, children, teenagers, and adult females and males, respectively. Compared to other potential sources, human exposure to TCS from OTCs was limited in China-much less than TCS exposure through personal care products or indoor dust.

Urinary concentrations of parabens in Chinese young adults: implications for human exposure.

Parabens are widely used as preservatives in foods, cosmetics, and pharmaceuticals. However, recent studies have indicated that high and systemic exposure to parabens can be harmful to human health. Although a few studies have reported urinary paraben levels in western countries, studies on paraben exposure in the Chinese population are limited. China is currently a major producer of parabens in the world. In this study, 109 urine samples collected from Chinese young adults (approximately 20 years old) were analyzed for five parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl-parabens) by high-performance liquid chromatography-tandem mass spectrometry. Methyl-, propyl-, and ethyl-parabens were the three major paraben analogues found in all (100%) samples. The concentration of the sum of the five parabens ranged from 0.82 to 728 ng/mL with a geometric mean value of 17.4 ng/mL. Urinary concentration of parabens was 2-fold greater in females than in males. Based on the measured urinary concentrations, daily intake of parabens by the Chinese young adults was estimated and compared with those reported for United States adults. The estimated daily intakes (EDIurine) of parabens were 18.4 and 40.8 µg/kg bw/day for Chinese males and females, respectively, values that were lower than those reported for United States adults (74.7 µg/kg bw/day). Based on the reported concentrations of parabens in foods from China and the United States, the contribution of dietary intake to EDIurine was estimated to be 5.5, 2.6, and 0.42% for Chinese males, Chinese females, and United States adults, respectively, which indicates the significance of nondietary sources of parabens to human exposures.

Occurrence and ecological risk assessment of 16 phthalates in surface water of the mainstream of the Yangtze River, China.

Phthalic acid esters (PAEs), a class of typical endocrine disruptors, have received considerable attention due to their widespread applications and adverse effects on biological health. In this study, 30 water samples, along the mainstream of the Yangtze River (YR), were collected from Chongqing (upper stream) to Shanghai (estuary) from May to June in 2019. The total concentrations of 16 targeted PAEs ranged from 0.437 to 20.5 µg/L, with an average of 1.93 µg/L, where dibutyl phthalate (DBP, 0.222-20.2 µg/L), bis (2-ethylhexyl) phthalate (DEHP, 0.254-7.03 µg/L), and diisobutyl phthalate (DIBP, 0.0645-0.621 µg/L) were the most abundant PAEs. According to the pollution level in the YR to assess the ecological risk posed by PAEs, the results showed medium risk level of PAEs in the YR, among which DBP and DEHP posed a high ecological risk to aquatic organisms. The optimal solution for DBP and DEHP is found in ten fitting curves. The PNECSSD of them is 2.50 µg/L and 0.34 µg/L, respectively.

Parabens and bisphenol A and its structural analogues in over-the-counter medicines from China.

Pharmaceuticals, such as over-the-counter (OTC) medicines, may be an important source of human exposure to several endocrine disruptors, though unnoticed to date. In the present study, we investigated the presence of six parabens and nine bisphenol A (BPA) and its analogues in OTC medicines manufactured in China. Parabens and bisphenols were present in more than 90% of the samples. The total measured concentrations of parabens and bisphenols were in the range of non-detectable (ND) to 213 ng/g and ND to 415 ng/g, respectively. Regarding parabens, methyl paraben (MeP) was the predominant analog, accounting for 43 ± 36% of the total amount, followed by ethyl paraben (EtP) (39 ± 35%), and others (< 10%). Bisphenol F and BPA were the predominant bisphenols, accounting for 24 ± 28% and 22 ± 26% of the total amount, respectively. The median values of estimated daily intakes (EDIs) of parabens and bisphenols were the highest for infants (2.96 and 3.14 ng/kg_bw/day, respectively) and the lowest for adults (0.69 and 0.25 ng/kg_bw/day, respectively); moreover, the EDIs of parabens and bisphenols were higher in Chinese patent medicines than in western pediatric medicines. The hazard quotient (HQ) for sum of MeP and EtP (∑(MeP + EtP)) and BPA in three age groups were within the safe zone (HQ < 0.0004). Monte Carlo simulation was applied to predict the human exposure risk of parabens and bisphenols. The predicted ranges of EDIs of parabens and bisphenols were much wider, and the extreme predicted values were observed in all four age groups, which were higher than the acceptable daily intake. The extreme predicted values of ∑(MeP + EtP) and BPA were indicative of carcinogenic risk in toddlers. These results implied potential risks for the Chinese people existed. Considering the huge export of Chinese traditional medicines and western medicines worldwide, and easy access to OTC medicines for the general population, the presence of parabens, bisphenols, and other environmental contaminants in medicines still need to be monitored.

Phthalates, bisphenols, parabens, and triclocarban in feminine hygiene products from the United States and their implications for human exposure.

Feminine hygiene products, a category of daily necessities, can be a source of exposure to plasticizers and antimicrobial agents in women. Nevertheless, studies on the occurrence of chemicals in feminine hygiene products have received little attention. In this study, 24 endocrine-disrupting chemicals (EDCs), comprising nine phthalates, six parabens, eight bisphenols, and triclocarban (TCC) were measured in seven categories of feminine hygiene products (i.e., pads, panty liners, tampons, wipes, bactericidal creams and solutions, and deodorant sprays and powders; N = 77) collected in the Albany area of New York State in the United States. Dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di-iso-butyl phthalate (DIBP), di(2-ethylhexyl) phthalate (DEHP), methyl paraben (MeP), and ethyl paraben (EtP) were found in all pad, panty liner, and tampon samples. Panty liners contained the highest concentrations of DMP (median: 249 ng/g), DEP (386 ng/g), DBP (393 ng/g), and DIBP (299 ng/g) and tampons contained the highest concentrations of DEHP (267 ng/g). MeP, EtP, and propyl paraben (PrP) were the major parabens found in feminine hygiene products. Bactericidal creams and solutions contained median concentrations of MeP, EtP and PrP at 2840, 734, and 278 ng/g, respectively. The estimated exposure doses of phthalates, parabens, and bisphenols through the dermal absorption pathway from the use of pads, panty liners, and tampons were significant. In comparison with the exposure doses reported previously from other sources and pathways, the significance of feminine hygiene products as sources of EDC exposure was delineated. The dermal absorption doses from the use of feminine hygiene products, under different exposure scenarios, were 0.19-27.9% and 0.01-6.2% of the total exposure doses of phthalates and bisphenols, respectively. This is the first study to report the occurrence of phthalates, parabens, bisphenols, and TCC in feminine hygiene products from the United States.

Hydroxylated polycyclic aromatic hydrocarbons in surface soil in an emerging urban conurbation in South China.

To investigate the effects of human activity on contaminants in regional soil, hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were measured in 187 surface soil samples of different land-use types collected from the Pearl River Delta (PRD), South China. The concentrations of Σ9OH-PAH (sum of nine target analytes) ranged from 0.36 to 252ng/g (median: 5.98ng/g), with phenanthrene derivatives as the dominant components, accounting for ~70%. Among different land-use types, residency soil contained the highest levels of Σ9OH-PAH (median: 11.3ng/g), followed by landfill soil (9.28ng/g), industry soil (7.51ng/g), agriculture soil (6.04ng/g), forestry soil (4.28ng/g) and drinking water source soil (4.20ng/g). A higher value was also observed in soil from the central PRD (6.94ng/g) than the surrounding areas (5.94ng/g), which indicated a significant impact of human activity on OH-PAH contamination in soil. Correlation and principal component analysis indicated that OH-PAHs in PRD soil are likely derived from the degradation of their parent PAHs in the atmosphere and/or soil and not directly from the same source as the parent PAHs. The ratios of OH-PAHs to their parent PAHs also varied among different land-use types, which may be partly attributed to the different populations of microorganisms in different soil types or the different chemical properties of PAHs and their metabolites.

The effects of prosperity indices and land use indicators of an urban conurbation on the occurrence of hexabromocyclododecanes and tetrabromobisphenol A in surface soil in South China.

Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are legacy brominated flame retardants which are still produced and used in China. In this study, 187 surface soils from the Pearl River Delta (PRD) urban conurbation in China were collected, and the effects of urban conurbation development on the concentrations, distributions and human exposure risk of HBCDs and TBBPA were investigated. The concentration ranges of Σ3HBCD (sum of α-, ß-, and γ-HBCD) and TBBPA in soil were below the limit of quantification (

Several environmental endocrine disruptors in beverages from South China: occurrence and human exposure.

Environmental endocrine disruptors (EEDs) in beverages may enter the human body by ingestion and thus may represent a potential health risk. In this study, phthalates, bisphenol A, and its analogues, parabens, benzophenone-type UV filters, and triclosan (TCS) were analyzed in beverage samples (n = 116) collected from local markets in Guangzhou, South China. Twelve of 30 target compounds were found in > 50% samples, and for the first time, TCS was found in a majority of beverages from China (~ 80%). Among all analytes, concentrations of total phthalates (median = 14.4 ng/mL) were generally two orders of magnitude higher than other target EEDs, and concentrations of total benzophenone-type UV filters (0.02 ng/mL) and TCS (0.01 ng/mL) were the lowest. Among all targets, phthalates were predominant, accounting for > 99% of the total EEDs, and dimethyl phthalate was frequently detected in beverages (> 60%). In addition, we estimated the daily intake (EDI) of EEDs for Chinese populations of different age groups based on the daily consumption of beverages. The EDIs of total EEDs were the highest for toddlers (mean = 14,200 ng/kg-bw/day) followed by children and teenagers (3420 ng/kg-bw/day), adults (1950 ng/kg-bw/day), the elderly (1740 ng/kg-bw/day), and infants (70 ng/kg-bw/day). Compared to all food categories, EEDs from beverage consumption accounted for ~ 0.1% (parabens) to 20% (phthalates) of total exposure from diet. However, intakes of phthalates, bisphenols, and TCS from beverages were comparable to those from other potential sources (food, dust, personal care products, cloth, and medicines). Furthermore, the cumulative risks of EEDs by beverage consumption were not high, which indicated that EEDs in beverages might not represent a potential human health risk for Chinese populations.

Occurrence of bisphenol S in the environment and implications for human exposure: A short review.

As a substitute of bisphenol A (BPA), bisphenol S (BPS) has been applied in consumer products present in our daily lives. With a similar chemical structure as BPA, BPS has also been demonstrated as an exogenous endocrine disrupting chemical. Compared with a large number of studies on BPA, investigation on BPS has remained limited. In this study, we reviewed the literature of BPS mainly published during 2010-2017, including its environmental distributions, toxicities, and human exposure. The data demonstrated that BPS is now ubiquitous in the environment and found worldwide, but generally with concentration levels lower than BPA in various environment media, including water, sediment, sludge, indoor dust and air, consumer products, and human urine. However, we found that the concentration levels of BPS in aquatic environments, especially water samples, were almost comparable or equal to that of BPA. Our summary also indicated that process speed of substituting BPA with BPS in consumer products in the U.S. was relatively faster than other countries. In addition, we summarized the toxicities of exposure to BPS both in vivo and in vitro experiments. The current data supports that exposure to BPS may have adverse effects on reproductive systems, endocrine systems, and nervous systems in animals and humans, and may trigger oxidative stress. The occurrence of BPS was frequently reported in human urine, but rarely in other human samples. The current research indicates that food is the dominant source for human exposure to BPS, and the contribution of personal care product usage is low. The occurrence of BPS and their metabolites in the human body and the guidelines for BPS exposure merit further investigation.

Occurrence, sources and human exposure assessment of SCCPs in indoor dust of northeast China.

Short-chain chlorinated paraffins (SCCPs) are widely used chemicals in household products and might cause adverse human health effects. However, limited information is available on the occurrence of SCCPs in indoor environments and their exposure risks on humans. In this study the concentrations, profiles and human exposure of SCCPs in indoor dust from five different indoor environments, including commercial stores, residential apartments, dormitories, offices and laboratories were characterized. The SCCPs levels ranged from 10.1 to 173.0 µg/g, with the median and mean concentration of 47.2 and 53.6 µg/g, respectively. No significant difference was found on concentrations among the five microenvironments. The most abundant compounds in indoor dust samples were homologues of C13 group, Cl7 group and N20 (N is the total number of C and Cl) group. In the five microenvironments, commercial stores were more frequently exposed to shorter carbon chained and higher chlorinated homologues. Three potential sources for SCCPs were identified by the multiple linear regression of factor score model and correspondence analysis. The major sources of SCCPs in indoor dust were technical mixtures of CP-42 (42% chlorine, w/w) and CP-52 b (52% chlorine, w/w). The total daily exposure doses and hazard quotients (HQ) were calculated by the human exposure models, and they were all below the reference doses and threshold values, respectively. Monte Carlo simulation was applied to predict the human exposure risk of SCCPs. Infants and toddlers were at risk of SCCPs based on predicted HQ values, which were exceeded the threshold for neoplastic effects in the worst case. Our results on the occurrences, sources and human exposures of SCCPs will be useful to provide a better understanding of SCCPs behaviors in indoor environment in China, and to support environmental risk evaluation and regulation of SCCPs in the world.

Phthalate metabolites in urine of Chinese young adults: Concentration, profile, exposure and cumulative risk assessment.

Phthalates are widely used in consumer products. People are frequently exposed to phthalates due to their applications in daily life. In this study, 14 phthalate metabolites were analyzed in 108 urine samples collected from Chinese young adults using high-performance liquid chromatography-tandem mass spectrometry. The total concentrations of 14 phthalate metabolites ranged from 71.3 to 2670 ng/mL, with the geometric mean concentration of 306 ng/mL. mBP and miBP were the two most abundant compounds, accounting for 48% of the total concentrations. Principal component analysis suggested two major sources of phthalates: one dominated by the DEHP metabolites and one by the group of mCPP, mBP and miBP metabolites. The estimated daily intakes of DMP, DEP, DBP, DiBP and DEHP were 1.68, 2.14, 4.12, 3.52 and 1.26-2.98 µg/kg-bw/day, respectively. In a sensitivity analysis, urinary concentration and body weight were the most influential variables for human exposure estimation. Furthermore, cumulative risk for hazard quotient (HQ) and hazard index (HI) were evaluated. Nearly half of Chinese young adults had high HI values exceeding the safe threshold. This is the first study on the occurrence and human exposure to urinary phthalate metabolites with Chinese young adults.

Phthalates in dormitory and house dust of northern Chinese cities: Occurrence, human exposure, and risk assessment.

Phthalates are widely used chemicals in household products, which severely affect human health. However, there were limited studies emphasized on young adults' exposure to phthalates in dormitories. In this study, seven phthalates were extracted from indoor dust that collected in university dormitories in Harbin, Shenyang, and Baoding, in the north of China. Dust samples were also collected in houses in Harbin for comparison. The total concentrations of phthalates in dormitory dust in Harbin and Shenyang samples were significantly higher than those in Baoding samples. The total geometric mean concentration of phthalates in dormitory dust in Harbin was lower than in house dust. Di-(2-ethylhexyl) phthalate (DEHP) was the most abundant phthalate in both dormitory and house dust. The daily intakes of the total phthalates, carcinogenic risk (CR) of DEHP, hazard index (HI) of di-isobutyl phthalate (DiBP), dibutyl phthalate (DBP), and DEHP were estimated, the median values for all students in dormitories were lower than adults who live in the houses. Monte Carlo simulation was applied to predict the human exposure risk of phthalates. HI of DiBP, DBP, and DEHP was predicted according to the reference doses (RfD) provided by the United States Environmental Protection Agency (U.S.EPA) and the reference doses for anti-androgenicity (RfD AA) developed by Kortenkamp and Faust. The results indicated that the risks of some students had exceeded the limitation, however, the measured results were not exceeded the limitation. Risk quotients (RQ) of DEHP were predicted based on China specific No Significant Risk Level (NSRL) and Maximum Allowable Dose Level (MADL). The predicted results of CR and RQ of DEHP suggested that DEHP could pose a health risk through intake of indoor dust.

Benzonphenone-type UV filters in urine of Chinese young adults: Concentration, source and exposure.

Benzophenone (BP)-type UV filters are commonly used in our daily life. 2-hydroxy-4-methoxy benzophenone (BP-3), 4-hydroxy benzophenone (4-HBP), 2,4-dihydroxy benzophenone (BP-1), 2,2',4,4'-tetrahydroxy benzophenone (BP-2) and 2,2'-dihydroxy-4-methoxy benzophenone (BP-8) were measured in urine samples from Chinese young adults. The results indicated that Chinese young adults were widely exposed to BP-3, BP-1, and 4-HBP, with the median concentrations of 0.55, 0.21, and 0.08 ng/mL, respectively. No significant difference was found between males and females, between urban and rural population. The correlations between urinary concentrations provided important indications for sources and metabolic pathways of target compounds. The estimated daily excretion doses of BP-3, 4-HBP, BP-1, BP-2 and BP-8 were 27.2, 2.24, 5.86, 0.76 and 0.30 ng/kg-bw/day, respectively. The ratio of exposure to excretion must be considered for the exposure assessment with chemicals based on urine measurement. This is the first nationwide study on BP-derivatives with young adults in China.