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1.
Ecotoxicol Environ Saf ; 188: 109837, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683044

RESUMO

Drinking water samples were collected from 71 cities, including 28 provincial capital cities or municipalities, 20 prefecture cities and 23 counties, of 31 provincial-level administrative regions in China from July to August in 2017. Futhermore, 24 Antibiotic Resistance Genes (ARGs), 16S rRNA and 2 integrase genes were quantified by qPCR to investigate the pollution degree of ARGs. The results revealed that the 16S ranged from 105 - 108 copies/100 mL in the drinking water, and its treatment process could effectively remove bacteria. Moreover, sulfonamides-ARGs were the most prevalent ARGs in the drinking water of China, and the abundance of blaTEM ranked top five in all cities among the selected ARGs, indicating that the pollution condition of the genes should be aroused more attention. The data of qPCR and correlation analyses indicated that intI1 played a more crucial role than intI2 in the propagation of ARGs in the drinking water. Additionally, the pollution degree of ARGs among different city types showed no significant difference.

2.
Sci Total Environ ; 697: 133997, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31479902

RESUMO

To recognize the occurrence and health risk of organophosphate esters (OPEs) in soil of residential areas, a nationwide survey was conducted covering 32 provincial-level administrative regions of China in 2018. Except for triamyl phosphate (TAP), twelve OPEs were detected in residential soil from 89 cities with a total concentration of 1.70-179 ng/g dw, indicating a relatively low contamination level of OPEs in residential soil of China (compared with point source soils and urban soils). Tris(1-chloro-2-propyl) phosphate (TCIPP) was the most abundant OPEs, followed by tris(2-butoxyethyl) phosphate (TBOEP), tris(2-chloroethyl) phosphate (TCEP) and triphenyl phosphate (TPHP), which suggested that TCIPP has been a replacement of TCEP in recent years. An apparent geographical distribution of higher OPEs levels in the Bohai Rim, the Yangtze Delta and Shanxi province than other regions was found. According to the division of administrative levels, the most serious OPEs pollution occurred in prefecture-level city (20.2 ng/g dw), followed by provincial capital (17.9 ng/g dw) and county town (14.1 ng/g dw), which was affected by the usage of OPEs products and behaviors of local residents. The correlation analysis results showed that environmental parameters (total organic carbon (TOC), precipitation and temperature) were not the major factors determining OPEs contamination, while socioeconomic parameters were significantly correlated with OPEs concentration in undeveloped regions/cities with rare industrial source. Although the health risk assessment suggested a negligible risk to local residents (5.92 × 10-7-1.75 × 10-6 for non-carcinogenic risk and 4.82 × 10-12-2.10 × 10-11 for carcinogenic risk), the production and usage of TCIPP and TCEP should be paid more attention due to their relatively high risks. Our study was attempted to provide a nationwide baseline concentration of OPEs in soil of residential areas, which could be used to support further studies.

3.
Environ Pollut ; 255(Pt 1): 113149, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31522007

RESUMO

Antibiotics have been widely detected in the ocean and have various impacts on the environment, while knowledge of their chronic influence on phytoplankton, especially red tide algae, is still limited. Dinoflagellates and green algae are common phytoplankton in marine ecosystems. The former is the main red tide algae, and the latter is an important primary producer. We investigated the long-term responses of two representative algae, Prorocentrum lima and Chlorella sp., to two common antibiotics (sulfamethoxazole (SMX) and norfloxacin (NFX)) at environmentally relevant levels (10 and 100 ng/L) during simulated natural conditions. The cell density and activities of three antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD)) were analyzed. The results showed that the influence of each antibiotic on Chlorella sp. was not significant (p > 0.05) during the first 10 days, but the influence of the antibiotics later began to show significant inhibition (p < 0.05) compared with the control group, especially during mixed exposure. P. lima was not inhibited, but its cell density increased. SMX had a superior stimulation effect on P. lima. The three enzymes activities of P. lima increased, and the antioxidant mechanism was not seriously impacted. However, for Chlorella sp., the activity of SOD increased while the activities of CAT and POD decreased, suggesting that this algae's antioxidant system was unbalanced due to oxidative stress. Based on our results, the growth of P. lima was different from green algae Chlorella sp. as well as other inhibited marine algae (such as diatom, golden algae) studied in previous studies. Therefore, as a typical pollutant in the ocean, antibiotics may play a positive role in the bloom of dinoflagellate red tides.

4.
Environ Sci Technol ; 53(18): 10763-10773, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31441645

RESUMO

The colonization characteristics of bacterial communities on microplastics or plastic debris (PD) have generated great concern in recent years. However, the influence of environmental factors and polymer types on the formation of bacterial communities on PD in estuarine areas is less studied. To gain additional insights, five types of PD (polyvinyl chloride, polypropylene, polyethylene, polystyrene, and polyurethane) were exposed for three-time periods (two weeks, four weeks, and six weeks) in the Haihe Estuary. 16S rRNA gene sequencing was used to identify the bacterial communities on PD, in seawater, and in sediment samples. The results indicate that the average growth rate of a biofilm is affected by nutrients (total nitrogen and total phosphorus) and salinity. Furthermore, salinity is the primary factor affecting bacterial diversity of the colonies on PD. In addition, genera of bacteria show selectivity toward the PD polymer type and tend to colonize their preferred substrate. Compared with seawater and sediment, PD could be carriers for enrichment of Vibrio in the estuarine environment with salinity ≥26 (± 2‰), which might increase the ecological risk of PD in marine environments.

5.
Environ Sci Process Impacts ; 21(7): 1143-1152, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31157347

RESUMO

Estuaries are considered to be seriously polluted by microplastics. As the most important water body in North China, the pollution level of microplastics in two typical estuaries (Haihe Estuary (HHE) and Yondingxinhe Estuary (YDXE)) of Bohai Bay is not well understood. The occurrence and distribution of microplastics in the surface water and sediment of HHE and YDXE were investigated. The mean concentration of microplastics in surface-water samples was 1485.7 ± 819.9 items per m3 for HHE and 788.0 ± 464.2 items per m3 for YDXE, respectively, whereas the concentration of microplastics in sediment was 216.1 ± 92.1 items per kg dw for HHE and 85.0 ± 40.1 items per kg dw for YDXE, respectively. The concentration of microplastics in surface-water and sediment-samples of HHE was higher than that of YDXE, though YDXE is a typical sewage-received river. Anthropogenic activities and the river input were the main sources of microplastic pollution in estuarine areas. Sewage rivers could be point sources of microplastic pollution on a small scale. The small size (particle diameter < 1 mm) of microplastics was a dominant feature, the most abundant shape was fiber and colored microplastics were found widely in YDXE and HHE. We provided detailed information on microplastic pollution to support their control and management in HHE and YDXE.


Assuntos
Baías/química , Monitoramento Ambiental/métodos , Estuários , Plásticos/análise , Rios/química , Poluentes Químicos da Água/análise , China
6.
Environ Pollut ; 252(Pt A): 103-109, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31146223

RESUMO

The 6:2 chlorinated polyfluoroalkyl ether sulfonic acids (6:2 Cl-PFAES), 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy)-propanoic acid (HFPO-DA) and perfluoroethylcyclohexane sulfonate (PFECHS) are emerging per- and polyfluoroalkyl substances (PFASs) that are being applied to replace phased-out PFASs, which have high persistency, high bioaccumulation potential and high toxicity. Recently, these emerging PFASs were observed in estuary and marine areas with a pollution level of ng/L. In this study, three levels (10 ng L-1, 100 ng L-1 and 1000 ng L-1) for these PFASs were selected to investigate the response of marine Chlorella sp. to 14 days of exposure. The growth of Chlorella sp. was significantly inhibited by each PFAS over time. Treatments with 1000 ng/L exposure caused the most severe reduction in growth for each PFAS treatment. For the first half of the experimental period (from Day 0 to Day 6), the influence of each PFAS was not significant (p > 0.05). However, treatments with all concentrations of 6:2 Cl-PFAES, HFPO-DA and 1000 ng L-1 PFECHS significantly reduced the growth of Chlorella sp. from Day 8. The superoxide dismutase (SOD) activities in Chlorella sp. were significantly increased (p < 0.05) when exposed to 6:2 Cl-PFAES, HFPO-DA and PFECHS. The catalase (CAT) and peroxidase (POD) activities in Chlorella sp. were significantly inhibited (p < 0.05) by each PFAS. The glutathione (GSH) contents in Chlorella sp. were significantly increased by each PFAS. However, the increases in GSH concentration in Chlorella sp. were low. The inhibition of algal growth was primarily due to the reduction of the activities of CAT and POD. PFECHS had the lowest toxicity among the three PFASs, and it induced less oxidized damage to Chlorella sp. In conclusion, as alternatives to phased-out PFASs, the emerging PFASs are not safe in aquatic environment, and attention should be paid to the management and restriction of these emerging PFASs.


Assuntos
Chlorella/crescimento & desenvolvimento , Chlorella/metabolismo , Fluorcarbonetos/toxicidade , Propionatos/toxicidade , Ácidos Sulfônicos/toxicidade , Poluentes Químicos da Água/toxicidade , Catalase/metabolismo , Estuários , Glutationa/análise , Peroxidase/metabolismo , Superóxido Dismutase/metabolismo
7.
Ecotoxicol Environ Saf ; 177: 108-116, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30978653

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are a kind of persistent toxic substances, which have been frequently detected in environmental media. However, studies on their occurrences and distributions in drinking water are insufficient and their composition profiles in drinking water are still not clear. In this study, we investigated 16 priority polycyclic aromatic hydrocarbons (PAHs) in drinking water from different administrative level cities throughout mainland China, analyzed the influences of anthropogenic activities on PAHs, and assessed the health risk of the PAHs in drinking water. On the national scale, the sum concentration of the 16 priority-controlled PAHs (∑16PAHs) designated by the U.S. Environmental Protection Agency (USEPA) was in a range of 3.89-231.39 (mean 56.25) ng L-1. With the decline of ∑16PAHs, the concentration of 3-ring PAHs decreased, while its proportion increased, indicating 3-ring PAHs might be more difficult to remove than other PAHs in drinking water. The geographical distribution of PAHs in drinking water of China was in a descending order of West (69.81 ng L-1) > South (61.95 ng L-1) > North (58.63 ng L-1) > East (39.21 ng L-1) > Northeast China (37.93 ng L-1). ∑16PAHs in drinking water of Prefecture-level City was the greatest (71.49 ng L-1) followed by Provincial Capital (52.12 ng L-1), County-level City (50.98 ng L-1) and Municipality (33.92 ng L-1). ∑16PAHs was significantly negatively correlated with the per capita GDP of sampling city (P < 0.01, n = 78), implying that waterworks is an effective way to control and reduce PAH pollution in drinking water. The carcinogenic risk of the 16 PAHs in drinking water of China was much greater than the non-carcinogenic risk.


Assuntos
Carcinógenos/análise , Água Potável/química , Monitoramento Ambiental , Poluição Ambiental/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Carcinógenos/química , China , Cidades , Água Potável/análise , Hidrocarbonetos Policíclicos Aromáticos/química , Medição de Risco , Poluentes Químicos da Água/química
8.
Environ Sci Pollut Res Int ; 26(11): 10854-10866, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30778928

RESUMO

Organophosphate esters (OPEs) are a kind of emerging contaminants, but the information about their pollution profile and ecological risk are still scarce in China. In this study, 31 surface water samples of Haihe River (China) were collected in November 2017, and 11 OPEs were measured, and the ecological risk of OPEs was assessed by means of species sensitivity distribution (SSD) method and assessment factor method. Additionally, Pearson correlation analysis and an international comparison with other rivers in the world were conducted. The results showed that total OPEs ranged from 23.98 to 824.72 ng L-1, and the mean value was 228.70 ng L-1. The concentration of OPEs decreased as follows: Tri(2-chloroisopropyl) phosphate (TCPP) > Tri(2-chloroethyl) phosphate (TCEP) > Triethyl phosphate (TEP) > Tributoxyethyl phosphate (TBEP) > Triphenyl phosphate (TPhP) > Tripropyl phosphate (TPrP) > Tri(2-ethylhexyl) phosphate (TEHP) > 2-ethylhexyl diphenyl phosphate (EHDPP) > Tri(1,3-dichloro-2-propyl)phosphate (TDCPP) > Tri-n-butyl phosphate (TnBP) > Tri-m-cresyl phosphate (TMPP). TCPP (19.54-160.82 ng L-1) and TCEP (N.D.-151.99 ng L-1) with the mean value of 76.67 and 53.13 ng L-1 respectively were identified as the richest OPEs in Haihe River. The concentration of OPEs slowly increased in the upper reaches of Haihe River, and it tended to be stable in the middle reaches of Haihe River and decreased rapidly from the downstream to the outer sea. Significantly positive correlations occurred among three chlorinated alkyl OPEs (TCEP, TCPP, and TDCPP), suggesting that they might come from the same source. Based on the comparison, the pollution condition of OPEs in Haihe River was low, and TCEP was found to be the most abundant OPEs in China but it was not that in Europe. The ecological risk assessment on the basis of assessment factor method suggested that the risk of OPEs in Haihe River for algae, crustacean, and fish was limited. In addition, the results of SSD method suggested that the combined ecological risk of four OPEs in Haihe River was also low. This study provides information about the pollution status of OPEs in the surface water of China to some extents and a project for the risk estimation based on SSD for prior and emerging flame retardants.


Assuntos
Monitoramento Ambiental/métodos , Retardadores de Chama/análise , Modelos Teóricos , Organofosfatos/análise , Rios/química , Poluentes Químicos da Água/análise , China , Ecossistema , Ésteres/análise
9.
Water Res ; 154: 84-93, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30772757

RESUMO

As one group of emerging pollutants, the threat of organophosphate esters (flame retardants and plasticizers, OPEs) to drinking water safety is not well recognized. Now, the oral reference dose (RfD) and oral cancer slope factor (SFO) of OPEs have been updated by USPEA, therefore the threat of OPEs to drinking water safety could be assessed. In this study, occurrence, health risk and key impact factor of OPEs in drinking water of China were analyzed covering 79 cities, whose population and gross domestic product (GDP) accounted for 28.8% and 44.1% of them in China, respectively. Total concentration of 14 common OPEs in drinking water was 13.42-265.48 ng/L. The exposure level of OPEs via ingestion of drinking water was much lower than that of food ingestion but was comparable with dust ingestion, inhalation and dermal absorption. A health assessment for OPEs via ingestion of drinking water suggested that the potential cancer risk occurred (>1.00E-6) but no obvious non-carcinogenic effects occurred (<1). Tris-(2,3-dibromopropyl) phosphate (TDBPP) contributed to about 72.4% of carcinogenic risk, which should be treated as "prior monitoring OPEs" in further studies. The occurrence and distribution of OPEs in drinking water of China have a good corresponding relationship with the Aihui-Tengchong Line, and drinking water treatment technology (DWTT) was found to be a key factor. Total OPEs, halogeno-OPEs and alkyl-OPEs in drinking water from advanced DWTT cities were much lower than those of conventional DWTT cities. Compared with conventional DWTT, advanced DWTT could reduce about 65.6% and 36.5% of carcinogenic risk and non-carcinogenic risk of OPEs, respectively. Considering the annual growth of OPEs consumption in China and world, further studies regarding the environmental threat of OPEs are required.


Assuntos
Água Potável , Retardadores de Chama , Neoplasias Bucais , China , Cidades , Monitoramento Ambiental , Ésteres , Humanos , Organofosfatos , Plastificantes , United States Environmental Protection Agency
10.
Environ Pollut ; 246: 34-44, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30529939

RESUMO

The concentrations and spatial occurrences of 17 legacy per- and polyfluoroalkyl substances (PFAS) and 4 emerging PFAS in the coastal water-dissolved phase, surface sediment phase and suspended particulate matter (SPM) in the coastal areas of Bohai Bay were investigated. In addition, the partition behaviors of PFAS in the water-SPM system and water-sediment system and the potential sources of PFAS in the marine environment were revealed. The total concentrations of PFAS (∑PFAS) in the water-dissolved phase, surface sediment and SPM were 20.5-684 ng/L, 2.69-25.0 ng/g dry weight (dw) and 4.39-527 ng/g dw, respectively. The level of PFAS contamination in the coastal areas of Shandong Province was higher than that in other areas. The average partition coefficients (log Kd) of PFAS in the water-SPM system and water-sediment system were 1.56-3.57 and 0.72-2.95, respectively. Long-chain PFAS and PFECHS (perfluoroethylcyclohexane sulfonate) have a higher log Kd than that of short-chain PFAS. PFAS with short carbon chains were mainly detected in the water-dissolved phase, but long-chain PFAS mainly occurred in the surface sediment and SPM phases. Source analysis based on the positive matrix factorization (PMF) model found that erosion inhibitor factories, aqueous film-forming foam factories, metal plating plants, fluoropolymer chemical manufacture and food contact materials were the main sources of PFAS in Bohai Bay. These results improved our understanding of the partitioning behavior and sources of PFAS in aquatic environments.


Assuntos
Baías/química , Monitoramento Ambiental , Fluorcarbonetos/análise , Sedimentos Geológicos/química , Material Particulado/análise , Poluentes Químicos da Água/análise , China , Análise Fatorial , Fluorcarbonetos/química , Modelos Químicos , Material Particulado/química , Poluentes Químicos da Água/química
11.
Environ Pollut ; 244: 66-71, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30321713

RESUMO

This paper investigated 10 carbapenemase genes and selected the hosts of these genes in the estuary of Bohai Bay. The results showed that the OXA-58 producer accounted for a large percentage of carbapenem resistant bacteria in the sampling points, whereas the VIM, KPC, NDM, IMP, GES, OXA-23, OXA-24, OXA-48 and OXA-51 producers were not detected in the study. In addition, 9 bacterial genera with 100% identical blaOXA-58 sequences, including Pseudomonas, Rheinheimera, Stenotrophomonas, Shewanella, Raoultella, Vibrio, Pseudoalteromonas, Algoriphagus, Bowmanella and Thalassospira, were isolated from seawater. It is suggested that the host of blaOXA-58 gene were varied and many kinds of them could survive in the seawater. Moreover, we preformed the quantitative RT-PCR and the result shown the abundance of blaOXA-58 fluctuated between 2.8×10-6 copies/16S and 2.46×10-4 copies/16S, which was of the same order of magnitude as some common antibiotic resistance genes in environment. Furthermore, the variation trend of blaOXA-58 gene suggested that pollution discharge and horizontal gene transfer could contribute to the increase of the gene in coastal area.


Assuntos
Bactérias/genética , Proteínas de Bactérias/genética , Carbapenêmicos , Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Estuários , Poluição da Água , beta-Lactamases/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Baías , Carbapenêmicos/farmacologia , Transferência Genética Horizontal , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Homologia de Sequência do Ácido Nucleico , Microbiologia da Água
12.
Environ Int ; 123: 87-95, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30502598

RESUMO

Perfluoroalkyl acids (PFAAs) are a group of emerging persistent organic pollutants (POPs), which have been ubiquitously detected in the environmental media. However, national scale investigations on their occurrence and distribution in drinking water are still insufficient. In this study, we detected the 17 priority PFAAs in drinking water from 79 cities of 31 provincial-level administrative regions throughout China, and investigated their occurrence and distribution. Additionally, we also analyzed the influencing factors on their profiles, such as the existence of industrial sources, socioeconomic factors (population density and GDP), and assessed levels of risk associated with contaminated drinking water. On the national scale, the sum concentrations of the 17 PFAAs (∑17PFAAs) in drinking water was in a range of 4.49-174.93 ng/L with a mean value of 35.13 ng/L. Among the 17 individual PFAAs, perfluorobutanoic acids (PFBA) was the most abundant individual PFAAs with the median concentration of 17.87 ng/L, followed by perfluorooctanoic acid (PFOA, 0.74 ng/L), perfluorononanoic acid (PFNA, 0.40 ng/L) and perfluorooctane sulfonic acid (PFOS, 0.25 ng/L). The geographic distribution characteristic of ∑17PFAAs in drinking water was in a descending order of Southwestern China (57.67 ng/L) > Eastern coastal China (32.85 ng/L) > Middle China (29.89 ng/L) > Northwestern China (28.49 ng/L) > Northeastern China (22.03 ng/L), and in general, the existence of the industrial sources could positively affect the contamination levels of PFAAs in drinking water. The pollution level of PFAAs in drinking water also varied among the three different city levels (medium-sized city > big city > town). In towns, the positive correlations were observed between the population density and the ∑17PFAAs (R2 = 0.45, p < 0.01), and the individual concentration of PFHxA, PFBS, and PFOA (p < 0.01). Moreover, besides PFAAs in Yunnan, Jiangsu, and Jiangxi, concentrations of related PFAAs in drinking water from 28 provinces were less than the suggested drinking water advisories. The relatively higher concentrations of PFAAs in Yunnan, Jiangsu, and Jiangxi suggest that further studies focusing on their sources and potential health risk to humans are needed.

13.
Ecotoxicol Environ Saf ; 163: 427-435, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30075445

RESUMO

In this study, the concentrations of trihalomethanes (THMs) in tap water and direct drinking water were analyzed, and based on the human behavior patterns and building parameters, the concentrations of THMs in indoor air were simulated with the water-air concentration conversion model. In addition, concentrations of THMs in human tissues were predicted based on physiologically based pharmacokinetic (PBPK) model, and the health risk of THMs for participants were estimated. Furthermore, the carcinogenic risk of mixtures according to the method proposed by USEPA and PBPK model based method were calculated and compared. The concentrations of chloroform, bromodichloromethane, dibromochloromethane and bromoform in tap water were 11.28-16.21, 4.83-6.28, 0.81-1.32 and 0.08-0.21 µg/L, and those in direct drinking water were 3.29-6.88, 0.35-0.47, 0.03-0.08 and 0.04-0.08 µg/L, respectively. The results of water-air concentration conversion model demonstrated that pollutants in air had a strong correlation with water-related activities. Multi-pathway PBPK model showed that THMs concentrations in liver, kidney and richly perfused tissue were higher than those in other tissues. The results of risk assessment showed that the mean risk levels of mixtures were 1.69 × 10-4 and 1.72 × 10-4 calculated by the USEPA recommended method and PBPK based method, which seriously exceeded the acceptable level. TCM and BDCM were the major risk factors, and inhalation was the main exposure route of THMs.


Assuntos
Exposição Ambiental/efeitos adversos , Modelos Teóricos , Neoplasias/induzido quimicamente , Trialometanos/toxicidade , Poluentes Químicos da Água/toxicidade , Interações de Medicamentos , Exposição Ambiental/análise , Humanos , Medição de Risco , Fatores de Risco , Trialometanos/análise , Trialometanos/farmacocinética , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/farmacocinética , Abastecimento de Água
14.
J Environ Sci (China) ; 65: 179-189, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29548389

RESUMO

The characteristics of dissolved organic matter (DOM) and bromide ion concentration have a significant influence on the formation of disinfection by-products (DBPs). In order to identify the main DBP precursors, DOM was divided into five fractions based on molecular weight (MW), trihalomethane formation potential and haloacetic acid formation potential were determined for fractions, and the change in contents of different fractions and total DBPs during treatment processes (pre-chlorination, coagulation, sand filtration, disinfection) were studied. Moreover, the relationship between bromide concentration and DBP generation characteristics in processes was also analyzed. The results showed that the main DBP precursors were the fraction with MW <1kDa and fraction with MW 3-10kDa, and the DBP's generation ability of lower molecular weight DOM (<10kDa) was higher than that of higher molecular weight DOM. During different processes, pre-chlorination and disinfection had limited effect on removing organics but could alter the MW distribution, and coagulation and filtration could effectively remove organics with higher MW. For DBPs, trihalomethanes (THMs) were mainly generated in pre-chlorination and disinfection, while haloacetic acids (HAAs) were mostly generated during pre-chlorination; coagulation and sand filtration had little effect on THMs but resulted in a slight removal of HAAs. In addition, the results of ANOVA tests suggested that molecular sizes and treatment processes have significant influence on DBP formation. With increasing bromide concentration, the brominated DBPs significantly increased, but the bromine incorporation factor in the processes was basically consistent at each concentration.


Assuntos
Brometos/análise , Desinfetantes/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Halogenação , Peso Molecular , Trialometanos/análise
15.
Sci Total Environ ; 631-632: 81-91, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29524905

RESUMO

In our study, health risk levels of different age groups of residents living in the vicinity of a municipal solid waste incinerator (MSWI) posed by polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in atmosphere and soil were evaluated. The toxic equivalent concentrations of PCDD/Fs (TEQ) in surrounding atmosphere and soil of studied MSWI were 0.05-0.12 pg I-TEQ Nm-3 and 7.622-15.450 ng I-TEQ kg-1, respectively. The PCDFs/PCDDs (F/D) values of PCDD/Fs in surrounding atmosphere of studied MSWI ranged from 0.40 to 5.90 with a mean of 1.80, suggesting that the PCDD/Fs mainly came from combustion sources and studied MSWI could be a key source of PCDD/Fs in surrounding atmosphere. The F/D ratios of PCDD/Fs in surrounding soil ranged from 0.18 to 1.81 with a mean of 0.90, suggesting combustion is not the mainly sources of PCDD/Fs in surrounding soil, and studied MSWI may have limited influence on PCDD/Fs in surrounding soil. O8CDD and 2,3,4,7,8-P5CDF could be the total PCDD/Fs and TEQ indicators in surrounding atmosphere of studied MSWI, respectively. The carcinogenic risk (CR) values of PCDD/Fs in surrounding atmosphere and soil for children, teens and adults were 1.24E-06, 9.06E-07 and 4.41E-06, respectively, suggesting that the potential cancer risk occurred but the risk was at acceptable levels for both children and adults (<1.00E-05), and the cancer risk for teens was negligible (<1.00E-06). The non-carcinogenic risk (non-CR) values of three age groups were lower than 1, indicating that no obvious non-carcinogenic effects occurred. Inhalation of air was the largest contributor of health risk (both CR and non-CR) for three age groups. In addition, a comparison of the health risk between PCDD/Fs and other emerging contaminants and traditional pollutants in soil and atmosphere was performed, which will help us have a good view of the health risk levels of PCDD/Fs in surrounding environment of MWSI.


Assuntos
Dibenzofuranos Policlorados/análise , Exposição Ambiental/estatística & dados numéricos , Incineração , Dibenzodioxinas Policloradas/análise , Adulto , Poluentes Atmosféricos/análise , Atmosfera/química , Criança , Monitoramento Ambiental , Humanos , Risco , Solo/química , Poluentes do Solo/análise
16.
Environ Pollut ; 236: 126-136, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29414333

RESUMO

Coastal areas are the transition zones between ocean and land where intracellular antibiotic resistance genes (iARGs) and extracellular antibiotic resistance genes (eARGs) could spread among marine organisms, and between humans and marine organisms. However, little attention has been paid to the combined research on iARGs and eARGs in marine environment. In this context, we collected water and sediment samples from the coastal areas of the Bohai Bay in China and performed molecular and chemical analyses. The results of quantitative real-time PCR (qPCR) showed that the relative abundance of eARGs was up to 4.3 ±â€¯1.3 × 10-1 gene copies/16S rRNA copies in the water samples and 2.6 ±â€¯0.3 × 10-3 gene copies/16S rRNA copies in the sediment samples. Also, the abundance of eARGs was significantly higher than that of iARGs. Furthermore, the average abundances of antibiotic resistance genes (ARGs, include iARGs and eARGs) were the highest in both the water and sediment samples from the estuaries. The results of liquid chromatography-mass spectrometry showed that the concentrations of antibiotics in estuaries and areas near the mariculture site were higher than that in the other sites. The class 1 integron gene (int1) and sul1 in the intracellular DNA were significantly correlated in the water samples. Moreover, significant correlation between int1 and sul2 in the extracellular DNA was also found in the sediment samples. The combination of sulfamerazine and tetracycline as well as the combination of sulfamethazine and dissolved oxygen can both explain the abundance of ARGs, implying the combined effects of multiple stresses on ARGs.


Assuntos
Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Genes Bacterianos , Poluição da Água/análise , Antibacterianos/análise , Baías , China , Estuários , Cromatografia Gasosa-Espectrometria de Massas , Integrons , RNA Ribossômico 16S/genética , Tetraciclina/análise
18.
Chemosphere ; 200: 201-208, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29486359

RESUMO

The ocean is the final place where pollutants generated by human activities are deposited. As a result, the long-range transport of the ocean can facilitate the diffusion of terrestrial contaminants, including ARGs. However, to our knowledge, little research has been devoted to discussing the content change of terrestrial ARGs and the reason for the change in coastal area. This study established various microcosms, in which seawater and freshwater were mixed at different ratio to simulate the environmental conditions of different regions in coastal areas. Four ARGs were quantified, and 16S pyrosequencing was conducted. The results showed that the terrestrial ARGs influenced the concentration of the corresponding ARGs in coastal areas, and the content change pattern of each ARG was distinct. The influence of salinity on the ARG content was limited in most cases. Moreover, most dominant bacteria from freshwater had significant positive correlation (p < 0.05) with selected ARGs, except for blaTEM. The dominant bacteria in freshwater diminished dramatically in microcosms with a high proportion of seawater. Freshwater may have a strong impact on the bacteria composition of seawater, and the materials from freshwater may prompt the growth of some bacteria (include potential hosts of ARGs) in coastal area.


Assuntos
Bactérias/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Água Doce/microbiologia , Genes Bacterianos/efeitos dos fármacos , Água do Mar/microbiologia , Antibacterianos/farmacologia , Bactérias/genética , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Humanos , RNA Ribossômico 16S , Salinidade
19.
Chemosphere ; 193: 403-411, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29154115

RESUMO

The eutrophication of surface water has been the main problem of water quality management in recent decades, and the ecological risk of microcystin-LR (MC-LR), which is the by-product of eutrophication, has drawn more attention worldwide. The aims of our study were to determine the predicted no effect concentration (PNEC) of MC-LR and to assess the ecological risk of MC-LR in the upstream section of the Haihe River. HC5 (hazardous concentration for 5% of biological species) and PNEC were obtained from a species sensitivity distribution (SSD) model, which was constructed with the acute toxicity data of MC-LR on aquatic organisms. The concentrations of MC-LR in the upstream section of the Haihe River from April to August of 2015 were analysed, and the ecological risk characteristics of MC-LR were evaluated based on the SSD model. The results showed that the HC5 of MC-LR in freshwater was 17.18 µg/L and PNEC was 5.73 µg/L. The concentrations of MC-LR ranged from 0.68 µg/L to 32.21 µg/L and were obviously higher in summer than in spring. The values of the risk quotient (RQ) ranged from 0.12 to 5.62, suggesting that the risk of MC-LR for aquatic organisms in the river was at a medium or high level during the study period. Compared with other waterbodies in the world, the pollution level of MC-LR in the Haihe River was at a moderate level. This research could promote the study of the ecological risk of MC-LR at the ecosystem level.


Assuntos
Ecossistema , Eutrofização , Microcistinas/análise , Rios/química , Poluição da Água/análise , Organismos Aquáticos/efeitos dos fármacos , Água Doce/análise , Microcistinas/toxicidade , Medição de Risco/métodos , Qualidade da Água/normas
20.
Environ Pollut ; 236: 899-906, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29157971

RESUMO

To estimate the health risk of haloacetonitriles in different kinds of drinking water, the concentrations of haloacetonitriles in tap water, boiled water and direct drinking water were detected. The physiologically based pharmacokinetic (PBPK) model was used to calculate internal dose in the human body for haloacetonitriles through ingestion, and the probability distributions of the non-carcinogenic risk of haloacetonitriles for human via drinking water were assessed. This study found that the mean concentrations of dichloroacetonitrile (DCAN) in tap water, boiled water and direct drinking water were 0.955 µg/L, 0.207 µg/L and 0.127 µg/L, and those of dibromoacetonitrile (DBAN) were 0.221 µg/L, 0.104 µg/L, 0.089 µg/L, respectively. In China, direct drinking water is used most frequently, so the concentrations of haloacetonitriles in direct drinking water were used to obtain data on the internal dose of haloacetonitriles. In addition, the simulation results for the PBPK model showed that the highest and lowest concentrations of DCAN occurred in the liver and venous blood, respectively. The peak concentrations of DBAN in each tissue were in the decreasing order liver > rapidly perfused tissue > kidney > slowly perfused tissues > fat > arterial blood (venous blood). In addition, the highest 95th percentile hazard quotients (HQ) value of haloacetonitriles via drinking water for humans was 8.89 × 10-3, much lower than 1. The 95th percentile hazard index (HI) was 0.046, which was also lower than 1, suggesting that there was no obvious non-carcinogenic risk.


Assuntos
Acetonitrilos/análise , Água Potável/química , Poluentes Químicos da Água/análise , China , Humanos , Medição de Risco , Abastecimento de Água
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