Seasonal patterns, fate and ecological risk assessment of pharmaceutical compounds in a wastewater treatment plant with Bacillus bio-reactor treatment.

Pharmaceutical compounds (PhCs) pose a growing concern with potential environmental impacts, commonly introduced into the environment via wastewater treatment plants (WWTPs). The occurrence, removal, and season variations of 60 different classes of PhCs were investigated in the baffled bioreactor (BBR) wastewater treatment process during summer and winter. The concentrations of 60 PhCs were 3400 ± 1600 ng/L in the influent, 2700 ± 930 ng/L in the effluent, and 2400 ± 120 ng/g dw in sludge. Valsartan (Val, 1800 ng/L) was the main contaminant found in the influent, declining to 520 ng/L in the effluent. The grit chamber and BBR tank were substantially conducive to the removal of VAL. Nonetheless, the BBR process showcased variable removal efficiencies across different PhC classes. Sulfadimidine had the highest removal efficiency of 87 ± 17% in the final effluent (water plus solid phase). Contrasting seasonal patterns were observed among PhC classes within BBR process units. The concentrations of many PhCs were higher in summer than in winter, while some macrolide antibiotics exhibited opposing seasonal fluctuations. A thorough mass balance analysis revealed quinolone and sulfonamide antibiotics were primarily eliminated through degradation and transformation in the BBR process. Conversely, 40.2 g/d of macrolide antibiotics was released to the natural aquatic environment via effluent discharge. Gastric acid and anticoagulants, as well as cardiovascular PhCs, primarily experienced removal through sludge adsorption. This study provides valuable insights into the intricate dynamics of PhCs in wastewater treatment, emphasizing the need for tailored strategies to effectively mitigate their release and potential environmental risks.

Modeling historical budget for ß-Hexachlorocyclohexane (HCH) in the Arctic Ocean: A contrast to α-HCH.

The historical annual loading to, removal from, and cumulative burden in the Arctic Ocean for ß-hexachlorocyclohexane (ß-HCH), an isomer comprising 5-12% of technical HCH, is investigated using a mass balance box model from 1945 to 2020. Over the 76 years, loading occurred predominantly through ocean currents and river inflow (83%) and only a small portion via atmospheric transport (16%). ß-HCH started to accumulate in the Arctic Ocean in the late 1940s, reached a peak of 810 t in 1986, and decreased to 87 t in 2020, when its concentrations in the Arctic water and air were ∼30 ng m-3 and ∼0.02 pg m-3, respectively. Even though ß-HCH and α-HCH (60-70% of technical HCH) are both the isomers of HCHs with almost identical temporal and spatial emission patterns, these two chemicals have shown different major pathways entering the Arctic. Different from α-HCH with the long-range atmospheric transport (LRAT) as its major transport pathway, ß-HCH reached the Arctic mainly through long-range oceanic transport (LROT). The much higher tendency of ß-HCH to partition into the water, mainly due to its much lower Henry's Law Constant than α-HCH, produced an exceptionally strong pathway divergence with ß-HCH favoring slow transport in water and α-HCH favoring rapid transport in air. The concentration and burden of ß-HCH in the Arctic Ocean are also predicted for the year 2050 when only 4.4-5.3 t will remain in the Arctic Ocean under the influence of climate change.

Real-world cost-effectiveness analysis of the fracture liaison services model of care for hip fracture in Taiwan.

BACKGROUND: This study was to perform an economic evaluation to understand clinical outcomes and health resource use between hip fracture patients receiving hospital-based postfracture fracture liaison service (FLS) care and those receiving usual care (UC) in Taiwan. METHODS: This cohort study included hospital-based data of 174 hip fracture patients who received FLS care (FLS group) from National Taiwan University Hospital, and 1697 propensity score-matched patients who received UC (UC group) of National Health Insurance claim-based data. Two groups had similar baseline characteristics but differed in hip fracture care after propensity score matching. Clinical outcomes included refracture-free survival (RFS), hip-refracture-free survival (HRFS), and overall survival (OS). Health resource use included inpatient, outpatient, and pharmacy costs within 2 years follow-up after the index of hip fracture. The economic evaluation of the FLS model was analyzed using the net monetary benefit regression framework based on the National Health Insurance perspective. RESULTS: The FLS group had longer RFS than the UC group, with an adjusted difference of 44.3 days (95% confidence interval: 7.2-81.4 days). Two groups did not differ in inpatient and outpatient costs during follow-up, but the FLS group had a higher expenditure than the UC group on osteoporosis-related medication. The probability of FLS being cost-effective was >80% and of increasing RFS, HRFS, and OS was 95%, 81%, and 80%, respectively, when the willingness-to-pay threshold was >USD 65/gross domestic product per day. CONCLUSION: FLS care was cost-effective in reducing refracture occurrence days for patients initially diagnosed with hip fractures.

Global, regional, and national prevalence, disability adjusted life years, and time trends for refraction disorders, 1990-2019: findings from the global burden of disease study 2019.

BACKGROUND: To evaluate global burden of refraction disorders by year, age, region, gender, socioeconomic status and other national characteristics in terms of disability adjusted life years (DALYs) and prevalence from Global Burden of Disease (GBD) study 2019 and World Bank Open Data 2019. METHODS: Global, regional, and national DALY numbers, crude DALY rates, age-standardized DALY and prevalence rates of refraction disorders were acquired from the GBD study 2019. Mobile cellular subscriptions, urban population, GDP per capita, access to electricity and total fertility rate were obtained from the World Bank to explore the factors that influenced the health burden of refraction disorders. Kruskal-Wallis test, linear regression and multiple linear regression were performed to evaluate the associations between the health burden with socioeconomic levels and other national characteristics. Wilcoxon Signed-Rank Test was used to investigate the gender disparity. RESULTS: Globally, age-standardized DALY rates of refraction disorders decreased from 88.9 (95% UI: 60.5-120.3) in 1990 to 81.5 (95% UI: 55.0-114.8) in 2019, and might fall to 73.16 (95% UI: 67.81-78.51) by 2050. Age-standardized prevalence rates would also reduce to 1830 (95% UI: 1700-1960) by 2050, from 2080 (95% UI: 1870-2310) in 1990 to 1960 (95% UI: 1750-2180) in 2019. In low SDI region, age-standardized DALY rates (equation: Y = 114.05*X + 27.88) and prevalence rates (equation: Y = 3171.1*X + 403.2) were positively correlated with SDI in linear regression respectively. East Asia had the highest blindness rate caused by refraction disorders in terms of age-standardized DALY rates (11.20, 95% UI: 7.38-16.36). Gender inequality was found among different age groups and SDI regions. CONCLUSION: Health burden of refraction disorders decreased in recent years, and may continue to alleviate in the next three decades. Older ages, females and lower socioeconomic status were associated with higher refraction disorders health burden.

Fate processes of Parabens, Triclocarban and Triclosan during wastewater treatment: assessment via field measurements and model simulations.

The high levels of parabens (including methyl-, ethyl- and propyl congeners), triclocarban (TCC) and triclosan (TCS) used every year in China might be a problem to the typical wastewater treatment plant (WWTP). This study addresses measurements of parabens, TCC and TCS Northern China WWTP and a modelling assessment on the occurrence, fate and removal pathways in WWTP. Per-capita emissions of the three parabens, TCC and TCS to the WWTP were estimated as 0.41, 0.11 and 0.07 mg/d. After the wastewater treatment processes, 94, 92 and 87% of parabens, TCC and TCS were removed. The major removal pathway of parabens was biodegradation while that of TCC and TCS were sorption to sludge. Computer simulations on the fate processes of parabens, TCC and TCS in the WWTP using the SimpleTreat 4.0 model suggested the model could generally reproduce the measurements with root mean squared errors (RMSEs) of less than 10 ng/L. However, the model underestimated the removal of TCC and TCS from water to sludge in the primary tank. These discrepancies were attributed to the uncertainty of the predicted organic carbon-water partition coefficients (Koc) to which the modelling results are highly sensitive. The model predictions using updated Koc became more accurate and RMSEs of TCC and TCS were reduced by 40 and 80%, respectively. The modelling assessment suggests that the SimpleTreat, as a generic model to simulate chemical fate processes in WWTPs, has the potential to be applied to other similar WWTPs in China for estimating environmental releases of parabens, TCC and TCS at a larger spatial scale.

Assessment bioaccumulation factor (BAF) of methyl siloxanes in crucian carp (Carassius auratus) around a siloxane production factory.

Methyl siloxanes are identified as emerging persistent toxic compounds and the ecological environment risks of these compounds have been caused of great concern worldwide. In this study, the concentrations of methyl siloxanes were reported in dissolved water and crucian carp around a methyl siloxane production factory located in Liaoning Province, Northeast China. D4, D5, D6, D7, L4, L5 and L6 were detectable both in dissolved water and crucian carp. The total concentrations of 7 methyl siloxanes (Σ7MS) were 14 ± 6.3 ng/L in dissolved water and 43 ± 22 ng/g ww in crucian carp, respectively. D5 has the highest concentration both in dissolved water (5.5 ± 3.5 ng/L) and crucian carp (17 ± 11 ng/g ww). Based on the monitoring values, bioaccumulation factor (BAF) of these compounds were calculated. Significant bioaccumulation potential was observed for D4 (BAF = 5900 ± 3500 L/kg) based on the bioaccumulation criteria suggested by USEPA and EU (BAF > 5000 L/kg). To our understanding, this is the first report of BAF values of methyl siloxane in field study, which will provide important support for further assessment of bioaccumulation of these compounds.

Occurrence, variations, and risk assessment of neonicotinoid insecticides in Harbin section of the Songhua River, northeast China.

Neonicotinoid insecticides (NNIs) have been intensively used and exploited, resulting in their presence and accumulation in multiple environmental media. We herein investigated the current levels of eight major NNIs in the Harbin section of the Songhua River in northeast China, providing the first systematic report on NNIs in this region. At least four NNIs in water and three in sediment were detected, with total concentrations ranging from 30.8 to 135 ng L-1 and from 0.61 to 14.7 ng g-1 dw, respectively. Larger spatial variations in surface water NNIs concentrations were observed in tributary than mainstream (p < 0.05) due to the intensive human activities (e.g., horticulture, urban landscaping, and household pet flea control) and the discharge of wastewater from many treatment plants. There was a significant positive correlation (p < 0.05) between the concentrations of residual imidacloprid (IMI), clothianidin (CLO), and Σ4NNIs in the sediment and total organic carbon (TOC). Due to its high solubility and low octanol-water partition coefficient (K ow), the sediment-water exchange behavior shows that NNIs in sediments can re-enter into the water body. Human exposure risk was assessed using the relative potency factor (RPF), which showed that infants have the highest exposure risk (estimated daily intake (ΣIMIeq EDI): 31.9 ng kg-1 bw·d-1). The concentration thresholds of NNIs for aquatic organisms in the Harbin section of the Songhua River were determined using the species sensitivity distribution (SSD) approach, resulting in a value of 355 ng L-1 for acute hazardous concentration for 5% of species (HC5) and 165 ng L-1 for chronic HC5. Aquatic organisms at low trophic levels were more vulnerable to potential harm from NNIs.

Association between economic development level and tuberculosis registered incidence in Shandong, China.

BACKGROUND: Tuberculosis (TB) is one of the major infectious diseases that seriously endanger people's health. In Shandong province, the relationship between the level of economic development and TB incidence has not been studied. This study aims to provide more research basis for the government to prevent and control TB by exploring the impact of different economic factors on TB incidence. METHODS: By constructing threshold regression model (TRM), we described the extent to which different economic factors contribute to TB registered incidence and differences in TB registered incidence among seventeen cities with different levels of economic development in Shandong province, China, during 2006-2017. Data were retrieved from the China Information System for Disease Control and Prevention. RESULTS: Per capita medical expenditure (regression coefficient, -0.0314462; SD, 0.0079305; P > |t|, 0.000) and per capita savings (regression coefficient, 0.0001924; SD, 0.0000566; P > |t|, 0.001) passed the significance test at the level of 1%.They are the two economic indicators that have the greatest impact on TB registered incidence. Through the threshold test, we selected the per capita savings as the threshold variable. In the three stages of per capita savings (<9772.8086 China Yuan(CNY); 9772.8086-33,835.5391 CNY; >33,835.5391 CNY), rural per capita income always has a significant negative impact on the TB registered incidence (The regression coefficients are - 0.0015682, - 0.0028132 and - 0.0022253 respectively. P is 0.007,0.000 and 0.000 respectively.).In cities with good economies, TB registered incidence was 38.30% in 2006 and dropped to 25.10% by 2017. In cities with moderate economies, TB registered incidence peaked in 2008 at 43.10% and dropped to 27.1% by 2017.In poorer cities, TB registered incidence peaked in 2008 at 56.30% and dropped to 28.9% in 2017. CONCLUSION: We found that per capita savings and per capita medical expenditure are most closely related to the TB incidence. Therefore, relevant departments should formulate a more complete medical system and medical insurance policy to effectively solve the problem of "difficult and expensive medical treatment". In order to further reduce the TB incidence, in addition to timely and accurate diagnosis and treatment, it is more important for governments to increase investment in medicine and health care.

Healthy living practices in families and child health: 5-year follow-up of Taiwan Birth Cohort Study.

OBJECTIVES: We have previously developed the Child Healthy Living Practices in Family (CHLPF) Index and found that the CHLPF Index was concurrently associated with the health of children at age 3. In this follow-up study, we aimed to examine whether healthy living practices in family at age 3 predicted health of children at school age. DESIGN AND SETTING: Data came from the Taiwan Birth Cohort Study designed to assess the development and health of 24 200 children born in 2005. PARTICIPANTS: A total of 18 553 cohort members whose mothers or primary caregivers had completed 6-month, 3-year, 5-year and 8-year surveys were included for analysis, representing a response rate of 87.3%. OUTCOME MEASURES: A multiple logistic regression model was used to test the relationship between mother-rated children's health at age 8 and the CHLPF Index level, after controlling for sex, birth outcomes, family structure, parental education, residential area, family income and mother-rated child's health at age 3. RESULTS: The percentage of mother-rated good health at age 8 was 79.7%. Compared with the low CHLPF level, the adjusted OR of mother-rated good health was 1.38 (95% CI 1.19 to 1.60), 1.21 (95% CI 1.10 to 1.35) and 1.17 (95% CI 1.07 to 1.29), respectively, for high, high-low and mid-low CHLPF levels. Moreover, the prevalence of mother-rated good health at age 8 with high-level CHLPF Index in the low-income group was similar to that of the high-income group (83.72% vs 84.18%); the prevalence with low-level CHLPF Index in the low-income group was much lower than that of the high-income group (70.21% vs 78.98%). CONCLUSIONS: Our study underscores that high level of healthy living practices in early childhood is positively associated with good health at school age, particularly for children from disadvantaged families.

PAHs in Chinese atmosphere Part II: Health risk assessment.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in atmosphere, which attracted more attentions due to their influence on human health. In this study, a national scale cancer risk (CR) assessment with atmospheric PAHs were conducted based on one year monitoring program at 11 cities across China. The annual mean concentrations of benzo[a]pyrene (BaP) and BaP equivalency (BaPeq) were 4.56 ± 7.78 ng/m3 and 8.45 ± 14.1 ng/m3, respectively, which were both higher than the new ambient air quality standards of China (GB 3095-2012, 1 ng/m3). Concentrations of BaP and BaPeq in northern Chinese cities were almost 2 times higher than those in southern Chinese cities. The CR values induced by the dermal contact exposure were two orders of magnitude higher than that by the inhalation exposure. Children and adults were the most sensitive age groups with the dermal contact exposure and the inhalation exposure to atmospheric PAHs, respectively. For the total CR values, 99.7% of its values were higher than the reference level of 10-6. No significant difference of the total CR values was observed between northern Chinese and southern Chinese cities for children and adults. In order to quantify the uncertainties of CR assessment, Monte Carlo Simulation was applied based on the specific distributions of the exposure factors cited from the Exposure Factors Handbook of Chinese Population. The results indicated that almost 90% probability of the total CR values were higher than 10-6, indicating potential cancer risk. Sensitive analysis indicated that atmospheric concentration, outdoor exposure fraction, particle amount adhered to skin, and cancer slope factor should be carefully considered in order to increase the accuracy of CR assessment with PAHs in atmosphere.

Indoor occurrence and health risk of formaldehyde, toluene, xylene and total volatile organic compounds derived from an extensive monitoring campaign in Harbin, a megacity of China.

Human exposure to formaldehyde, toluene, xylene (FTX) and other volatile organic compounds (VOCs) are associated with negative health impact. To characterize the exposure and health effects of FTX and TVOC from indoor environments, we conducted an extensive monitoring campaign involving 1278 measurements of 472 indoor locations in Harbin, a megacity in China from May 2013 to March 2018. The results showed that household had the highest mean formaldehyde concentration (0.171 ± 0.084 mg m-3) among all types of indoor environments. Meanwhile, there was no significant differences in formaldehyde concentration of the living room, master bedroom, secondary bedroom and study room (p > 0.05), as well as toluene and xylene. The highest mean concentration of toluene, xylene and TVOC was measured in public bath center. Great difference was found between formaldehyde concentrations in 2013 and other years, except 2015. There were great positive nonlinear correlations between the indoor temperature and concentration of formaldehyde (p < 0.01), good negative nonlinear correlations between the finish time of decoration and concentration of formaldehyde (p < 0.01), good positive linear correlations between the relative humidity and concentration of formaldehyde (p < 0.01). A risk assessment methodology was utilized to evaluate the potential adverse health effects of the individual FTX compounds according to their carcinogenicities. The predicted carcinogenic risk of formaldehyde was greater than the threshold value 1E-06 at all environments. The non-carcinogenic risk of TX compounds in the population is negligible. For estimating human health risk exposure, sensitivity analysis showed that more attention should be given to the influential variables such as the level of pollutants.

Organophosphate flame retardants in college dormitory dust of northern Chinese cities: Occurrence, human exposure and risk assessment.

Organophosphate flame retardants (OPFRs) are widely added to consumer products and building materials, which may pose potential health risk to humans. But information on their contamination and human exposure in the indoor environment especially dormitories in northern China is rare. In this study, twelve OPFRs were investigated in college dormitory dust that collected from Harbin, Shenyang, and Baoding, in northern China. Indoor dust samples were also collected from homes and public microenvironments (PMEs) in Harbin for comparison. The median ∑OPFR concentrations in dormitory dust in Shenyang samples (8690 ng/g) were higher than those in Baoding (6540 ng/g) and Harbin (6190 ng/g). The median ∑OPFR concentrations in home dust (7150 ng/g) were higher than in dormitory and PME dust (5340 ng/g) in Harbin. Tris(2­chloroethyl) phosphate (TCEP) and tris (2-chloroisopropyl) phosphate (TCIPP) were the most abundant chlorinated OPFRs, while triphenyl phosphate (TPHP) and tris(2­butoxyethyl) phosphate (TBOEP) were the dominant non-chlorinated OPFRs. The daily intakes of ∑OPFR were estimated, with the median values for female students (2.45 ng/kg-day) higher than those for male students (2.15 ng/kg-day) while were similar to adults (2.45 ng/kg-day) in homes. The estimated daily intakes (EDI) of these OPFRs from indoor dust in Harbin were all below the recommended values. The calculated non-carcinogenic hazard quotients (10-8-10-3) from OPFRs were much lower than the theoretical risk threshold. Meanwhile, carcinogenic risk (CR) of tri­n­butyl phosphate (TNBP), TCEP, tris(2­ethylhexyl) phosphate (TEHP), and tris(1,3­dichloroisopropyl) phosphate (TDCIPP) were also estimated. The highest carcinogenic risk of TCEP for gender-specific and age-specific category range from 1.75 × 10-7 to 2.46 × 10-7 from exposure to indoor dust indicated a low potential carcinogenic risk for human exposure.

Assessment of human indoor exposure to PAHs during the heating and non-heating season: Role of window films as passive air samplers.

The study of indoor organic film on planar surfaces has been shown to be important to assess the transport and fate of organic pollutants in indoor environments. Limited research showed the relationship between equilibrium status of polycyclic aromatic hydrocarbons (PAHs) and the growth days for indoor window films. To accomplish this goal, indoor window film samples were collected in relation to film growth days in Northeast China. PAHs were frequently detected in window films collected during heating season (H-season), with concentrations significantly higher than that of non-heating season (NH-season). Accumulation characteristics of PAH suggested that PAH concentrations (ng/m2 film) were growing near-linearly with time. Partitioning status for PAHs between gas and window films under different accumulation stage from 1 to 11 weeks was investigated during the two seasons. The equilibrium status of PAHs in the films suggested that the octanol-air partition coefficient (logKOA) of the targeted PAHs should be approximately <12 in order to reached the equilibrium stage within 11 weeks of growth. For all the growth days, the proportion of samples that reached equilibrium status for PAHs in the indoor window film samples were further calculated. The total air concentration of the target PAHs were predicted, giving median values of 900 and 240 ng/m3 in H-season and NH-season, respectively. Human health risk posed by PAHs was calculated in this research showing greater risks found for H-season than NH-season. The estimated incremental lifetime cancer risks were considered as safe with values lower than the WHO recommended guideline.

Spatial assessment of air resources in China from 2013 to 2017.

The concept of air resource management originated in the United States and subsequently became the foundation of most air quality control programs in developed countries. However, little is known about its validity and quantitative assessment methods in regional atmospheric environment management. The aim of this study was to construct an air resource endowment (ARE) index and apply it in a case study for assessing the distribution of ARE across mainland China from 2013 to 2017. The quantification of the ARE index includes two terms: the atmospheric diffusion coefficient (A value) and self-purification ability (B value), which can be calculated via Weather Research and Forecasting modeling (WRF-CALMET). The results indicated that about 15% of China's land area enjoys high ARE, around 20-25% of China's land area was considered to have relatively high or relatively low ARE indices, and ARE in the rest of China's land area (40%) was considered to be low. Further, a complex network correlation model was created and used to demarcate highly inter-correlated regions based on the data mining of the ARE index. Six key Joint Prevention and Control of Atmospheric Pollution (JPCAP) regions with strong synchronicity in the ARE index were identified, which suggests that JPCAP could be implemented separately within each of these demarcated regions. The concepts and analysis methods proposed in this study for determining ARE and regional divisions can have broad significance for JPCAP implementation in China.

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.

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.

Distribution patterns, infiltration and health risk assessment of PM2.5-bound PAHs in indoor and outdoor air in cold zone.

In this study we investigated the distribution patterns, infiltration and health risk assessment of PM2.5-bound PAHs in indoor and outdoor air done in Harbin city, northeastern China. Simultaneous indoor and outdoor sampling was done to collect 264 PM2.5 samples from four sites during winter, summer, and spring. Infiltration of PAHs into indoors was estimated using Retene, Benzo [ghi]perylene and Chrysene as reference compounds, where the latter compound was suggested to be a good estimator and subsequently used for further calculation of infiltration factors (IFs). Modeling with positive matrix factorization (PMF5) and estimation of diagnostic isomeric ratios were applied for identifying sources, where coal combustion, crop residues burning and traffic being the major contributors, particularly during winter. Linear discriminant analysis (LDA) has been utilized to show the distribution patterns of individual PAH congeners. LDA showed that, the greatest seasonal variability was attributed to high molecular weight compounds (HMW PAHs). Potential health risk of PAHs exposure was assessed through relative potency factor approach (RPF). The levels of the sum of 16 US EPA priority PAHs during colder months were very high, with average values of 377 ± 228 ng m(-)(3) and 102 ± 75.8 ng m(-)(3), for the outdoors and indoors, respectively. The outdoor levels reported to be 19 times higher than the outdoor concentrations during warmer months (summer + spring), while the indoor concentrations were suggested to be 9 times and 10 times higher than that for indoor summer (average 11.73 ± 4 ng m(-3)) and indoor spring (9.5 ± 3.3 ng m(-3)). During nighttime, outdoor PAHs revealed wider range of values compared to datytime which was likely due to outdoor temperature, a weather parameter with the strongest negative influence on ∑16PAHs compared to low impact of relative humidity and wind speed.

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.

Occurrence, behavior and human health risk assessment of dechlorane plus and related compounds in indoor dust of China.

Levels of dechlorane plus (DP) and "DP-like" compounds were measured in indoor dust samples collected across China. The concentrations of ΣDP and "DP-like" compounds ranged from 0.35 to 1,000 ng g(-1) and<0.21 to 2.4 ng g(-1), respectively. The total DP concentration in urban sites were significantly higher than those of rural sites, while no significant difference was found for "DP-like" compounds, suggesting different sources of these compounds. Significant positive correlations were found between fsyn and latitude, and between fsyn and longitude. The deleterious risk associated with DP exposure via indoor dust for the general population in China was low and safer than expectation. For estimating human exposure via indoor dust, sensitivity analysis showed that more attention should be given to the influential variables such as the level of pollutants, body weight, and the amount of ingestion and adsorption.

Polybrominated diphenyl ethers (PBDEs) in the indoor dust in China: levels, spatial distribution and human exposure.

Indoor environment is an important source of human exposure to several toxicants, such as brominated flame retardants. Indoor dust samples were collected in winter season in 2010, which covered 23 provinces across China, for the analysis of polybrominated diphenyl ethers (PBDEs). Concentrations of PBDEs (Σ14PBDEs) ranged from 8.92 to 37,500 ng/g, with the mean of 3520 ng/g. BDE-209 was the most dominate congener, followed by BDE-183, BDE-47 and BDE-99. PBDE concentrations and the longitude were significantly correlated (p<0.05), which was consistent with the status of social-economic development and human activities. The results of exposure to PBDEs through dust ingestion and dermal absorption indicated that the toddlers had the highest exposure dose, with the median value of 6.0 ng/kg-bw/day. According to the hazard quotients, health risk of PBDEs via dust ingestion in China is currently acceptable. Monte Carlo simulation was implemented to quantify the uncertainty and sensitivity of exposure models for determining the most influential variables. The results suggested that more specific and accurate parameters should be used for dust ingestion and dermal absorption exposure models in future.