[Distribution and health risk assessment of pesticide pollution in raw water and drinking water within key river basins in China in 2022].

OBJECTIVE: To investigate the distribution and exposure levels of pesticides in raw water and drinking water in China, as well as to assess the potential health risks associated with long-term consumption. METHODS: A total of 83 typical water plants were selected in key river basins in China to collected samples of the raw water, finished water, and tap water. The online-solid phase extraction coupled with liquid chromatography-tandem mass spectrometry method was used to determine 13 pesticides, including acetochlor, atrazine, dimethoate, malathion, carbofuran, dichlorvos, chlorpyrifos, parathion, trifluralin, isoprothiolane, simetryn, methyl parathion, and metalaxyl, as well as 6 environmental metabolites, including carbendazim, malaoxon, 3-hydroxycarbofuran, deethyl atrazine, deisopropyl atrazine and hydroxy atrazine. The carcinogenic and non-carcinogenic risks of these pesticides were assessed. RESULTS: The concentrations of total amount of pesticides in the samples ranged from 0.1 ng/L to 1299.4 ng/L, with a median value of 64.7 ng/L. The detection rates of 5 pesticides or their metabolites exceeds 80%, namely acetochlor, atrazine, hydroxyl atrazine, deethyl atrazine, and metalaxyl. More than 6 pesticides or their metabolites were detected in 77.7% of the total 498 samples. The total concentration of pesticides during the wet season ranged from 1.1 ng/L to 1299.4 ng/L, with a median of 69.2 ng/L and a median average daily dose of 2.3 ng/(kg·d). The total concentration of pesticides in the dry season samples ranged from 0.1 ng/L to 543.5 ng/L, with a median of 60.2 ng/L and a median average daily dose of 2.0 ng/(kg·d). Among the 498 samples, the maximum carcinogenic risk of dichlorvos was 2.0×10~(-7), and the maximum carcinogenic risk of trifluralin was 1.1×10~(-10). The non-carcinogenic HI of 19 pesticides and metabolites pesticides was ≤6.0×10~(-3). Among them, the maximum HI of the middle route of the South to North Water Diversion Project, the lower reaches of the Yellow River, the eastern route of the South to North Water Diversion Project, the Liaohe River, and the Songhua River basin was 2.0×10~(-3)-6.0×10~(-3), while the HI of other basins was less than 1.0×10~(-3). CONCLUSION: Different concentrations of pesticides have been detected in raw water, finished water, and tap water of key river basins in China, with the highest total concentration of detected reaching 1299.4 ng/L. The carcinogenic risk was lower than 10~(-6) and the non-carcinogenic hazard index of 19 pesticides was less than 1, and both below the acceptable level. Because of the universality and diverse occurrence of these pesticides in drinking water, long-term exposure to pesticides is still a concern.

Occurrence and distribution of pharmaceuticals in raw, finished, and drinking water from seven large river basins in China.

The occurrence of pharmaceuticals in the drinking water is a growing concern in China. In this study, we determined the concentration and distribution of 59 selected pharmaceuticals in raw, finished, and tap water samples from 79 drinking water treatment plants (DWTPs) in 15 cities, encompassing seven large river basins in China, using solid-phase extraction pretreatment and ultra-high-performance liquid chromatography-tandem mass spectrometry analysis. Forty-seven pharmaceuticals were detected in raw water samples, with detection rates of 1.27-96.20% and average concentrations of 0.09-128.87 ng/L. Forty-three pharmaceuticals were detected in finished water samples, with detection rates of 1.27-96.20% and average concentrations of 0.07-59.17 ng/L. Forty-two pharmaceuticals were detected in tap water samples, with detection rates of 1.27-94.94% and average concentrations of 0.07-58.43 ng/L. Purification methods implemented by DWTPs are capable of removing some pharmaceuticals from water treatment systems; however, low concentrations of pharmaceuticals were detected in drinking water, raising concerns about the possible human health implications of long-term exposure to low-dose pharmaceuticals. The detection and quantification of pharmaceuticals in municipal water samples presented in this study represent the most extensive analysis of commonly used pharmaceuticals and personal care products located in Chinese river basins.

Risk assessment and water safety plan: case study in Beijing, China.

Two typical rural water utilities in Beijing, China were chosen to describe the principles and applications of water safety plans (WSP), to provide a methodological guide for the actual application and improve the quality of rural drinking water quality, and to establish an appropriate method for WSP applied in rural water supply. Hazards and hazardous events were identified and risk assessment was conducted for rural water supply systems. A total of 13 and 12 operational limits were defined for two utilities, respectively. The main risk factors that affect the water safety were identified in water sources, water processes, water disinfection systems and water utility management. The main control measures were strengthening the water source protection, monitoring the water treatment processes, establishing emergency mechanisms, improving chemical input and operating system management. WSP can be feasibly applied to the management of a rural water supply.

[Study on the optimization of monitoring indicators of drinking water quality during health supervision].

OBJECTIVE: To optimize non-regular drinking water quality indices (except Giardia and Cryptosporidium) of urban drinking water. METHODS: Several methods including drinking water quality exceed the standard, the risk of exceeding standard, the frequency of detecting concentrations below the detection limit, water quality comprehensive index evaluation method, and attribute reduction algorithm of rough set theory were applied, redundancy factor of water quality indicators were eliminated, control factors that play a leading role in drinking water safety were found. RESULTS: Optimization results showed in 62 unconventional water quality monitoring indicators of urban drinking water, 42 water quality indicators could be optimized reduction by comprehensively evaluation combined with attribute reduction of rough set. CONCLUSION: Optimization of the water quality monitoring indicators and reduction of monitoring indicators and monitoring frequency could ensure the safety of drinking water quality while lowering monitoring costs and reducing monitoring pressure of the sanitation supervision departments.

Stabilize lead and cadmium in contaminated soils using hydroxyapatite and potassium chloride.

Combination of hydroxyapatite (HAP) and potassium chloride (KCl) was used to stabilize lead and cadmium in contaminated mining soils. Pot experiments of chilli (Capsicum annuum) and rape (Brassica rapachinensis) were used to evaluate the stabilization efficiency. The results were the following: (1) the optimal combination decreased the leachable lead by 83.3 and 97.27 %, and decreased leachable cadmium by 57.82 and 35.96% for soil HF1 and soil HF2, respectively; (2) the total lead and cadmium concentrations in both plants decreased 69 and 44 %, respectively; (3) The total lead and cadmium concentrations in the edible parts of both vegetables also decreased significantly. This study reflected that potassium chloride can improve the stabilization efficiency of hydroxyapatite, and the combination of hydroxyapatite and potassium chloride can be effectively used to remediate lead and cadmium contaminated mining soil.

Rare earth elements in human hair from a mining area of China.

Rare earth minerals have been mined for more than 50 years in Inner Mongolia of China. In the mining area rare earth elements (REE) may be significantly accumulated in humans. Therefore, the aim of this paper is to characterize the REE concentrations in hair of local residents. REE concentrations in hair of 118 subjects were determined. The results showed that the mean concentrations of the determined REE in the hair of both females and males were usually higher from mining area than from control area. The mean concentrations of all the fifteen REE were much higher in hair of males than in hair of females from mining area. This suggested that males might be more sensitive to REE than females. In addition, the mean contents of the REE in hair of miners, particularly light REE (La, Ce, Pr and Nd), were usually much higher than the values in hair of non-miners from both mining area and control area, indicating that the miners were exposed to higher concentrations of REE in occupational environment. Among age groups, the relationships between REE concentrations and age groups showed that more and more concentrations of light REE accumulated in body of both females and males with age until 60 years, while heavy REE concentrations decreased with age in males who were exposed to low concentrations of heavy REE.

Impacts of lead/zinc mining and smelting on the environment and human health in China.

Mining and smelting are important economic activities. However, mining-related industries are also some of the largest sources of environmental pollution from heavy metals. China is one of the largest producers and consumers of lead and zinc in the world. A large amount of lead, zinc, and related elements, such as cadmium, have been released into the environment due to mineral processing activities and have impacted water resources, soils, vegetables, and crops. In some areas, this pollution is hazardous to human health. This article reviews studies published in the past 10 years (2000-2009), on the environmental and human health consequences of lead/zinc mineral exploitation in China. Polluted areas are concentrated in the following areas: the junction of Yunnan, Guizhou and Sichuan provinces, west-central Hunan province, central Guangxi province, northern Guangdong, northwestern Henan province, the border between Shanxi and Gansu provinces, and the region of Liaoning province near Bohai. Lead (Pb) and cadmium (Cd) are the main pollutants and are associated with human health effects such as high lead blood levels in children, arthralgia, osteomalacia, and excessive cadmium in urine.

Environmental and Socioeconomic Factors for Gastric Cancer in 14 Counties of the Huai River Basin from 2014 to 2018.

To explore the potential relationship between environmental and socioeconomic factors and the risk of gastric cancer (GC) in the Huai River Basin, the GC incidence rate (GIR) and GC mortality rate (GMR) data from 2014 to 2018 in 14 counties of the Huai River Basin were collected from the Chinese Cancer Registration Annual Report. Environmental and socioeconomic parameters were collected through the Statistical Yearbook. The 14 counties were classified into three groups with low, moderate, and high risk of GC according to the point density of environmental factors (PDF) and index of socioeconomic factors (ISF). Significant differences in GIR and GMR were found among the counties with PDF (χ2 = 21.36, p < 0.01) and ISF (χ2 = 11.37, p < 0.05) levels. Meanwhile, significant differences in mortality rate were observed among counties with different PDF (χ2 = 11.25, p < 0.01) and ISF (χ2 = 18.74, p < 0.01), and the results showed that the ISF and PDF were increased while the GIR and GMR were decreased. Meanwhile, there was a lag effect between them, and we used two models to explore the lag effects between ISF, PDF and GIR and GMR; the coefficient influence between the ISF lag phase and GIR was -2.9768, and the coefficient influence between PDF and the lag phase on the GIR was -0.9332, and there were both significant impact when there was a probability of more than 95%. The results showed that the higher the ISF and PDF that lags in one stage, the more GIR was reduced, while the impact of the ISF and PDF on lag stage on mortality was not obvious. We used differential GMM to test the results, and also research results were relatively robust. Overall, GIR and GMR decreased with increasing point density of environmental factors and index of socioeconomic factors.

[Determination of 107 typical pesticides and metabolites in raw water and drinking water by online-solid phase extraction coupled with ultra performance liquid chromatography-triple quadrupole mass spectrometry].

In order to monitor the risk of pesticide pollutants in drinking water, an analytical method based on online-solid phase extraction coupled with ultra performance liquid chromatography-triple quadrupole mass spectrometry (online-SPE-UPLC-MS/MS) was established for the simultaneous rapid screening and determination of 107 pesticides and metabolites (organophosphorus, organic nitrogen, organic heterocycle, carbamate, amide, benzoyl urea, neonicotinoid, etc.) in raw water and drinking water. Different injection volumes (5, 10, and 15 mL) were compared. The detection response increased with an increase in the injection volume, but the matrix effect also became more pronounced. Under the premise of ensuring the sensitivity of the method and meeting the detection requirements, the injection volume was selected as 5 mL. Accordingly, the samples were filtered through a 0.22-µm hydrophilic polytetrafluoroethylene filter, and then, 5 mL samples were injected into the online-SPE system by the automatic sampler. After adsorption on an X Bridge C18 online-SPE column, the samples were washed with pure water and eluted by gradient elution using acetonitrile and 0.1% formic acid aqueous solution as the mobile phases, with separation on an ACQUITY HSS T3 column. The samples were detected by multiple reaction monitoring with electrospray ionization in positive and negative ion modes, and quantified by an external standard method. Using raw water and drinking water as the sample matrices, the accuracy and precision of the method were verified. The 107 pesticides and metabolites showed good linear relationships in different ranges with correlation coefficients (r2)>0.995. The limits of detection (LODs, S/N=3) of the method were 0.03-1.5 ng/L, and the limits of quantification (LOQs, S/N=10) were 0.1-5.0 ng/L. The target pesticides were spiked at concentration levels of 1, 20, and 50 ng/L. The spiked recoveries of the 107 targets in raw water and drinking water samples were 60.6%-119.8% and 61.2%-119.0%, respectively. The corresponding relative standard deviations (RSDs, n=6) were 0.3%-18.6% and 0.4%-17.1%. The pesticide residues in raw water and drinking water were determined by this method. Amide herbicides, triazine herbicides, triazole insecticides, carbamate insecticides, and neonicotinoid insecticides had high detection rates. The detected concentrations ranged from 0.1 to 97.1 ng/L in raw water and from 0.1 to 93.6 ng/L in drinking water. The sample consumption of online-SPE method was lower than that in the traditional off-line SPE methods, which greatly improved the convenience of sample collection, storage, and transportation. The samples only need to be filtered before injection and analysis. The method is simple to operate and shows good reproducibility. With this online-SPE method, only 23 min were required from online enrichment to detection completion. The developed method has the advantages of high analytical speed and high sensitivity. The method is suitable for the trace analysis and determination of 107 typical pesticides in raw water and drinking water, which effectively improves the detection efficiency of pesticides in water and has high potential for practical application. It can extend technical support for the pollution-level analysis of typical pesticides and metabolites in drinking water and provide an objective basis for human health risk assessment.

The Risk of CVDs from Desalinated Seawater: A Nested Case-Control Study.

The aim of this paper was to assess the association between desalinated seawater and cardiovascular diseases (CVDs). We conducted a nested case-control prospective study on a cohort of 7806 subjects who live on an island of China that lacks fresh water. From this cohort, we identified 140 paired CVD cases and matched controls by sex and age during the same period. Questionnaires were used in order to investigate basic sociodemographic information and risk factors for CVDs, and urine samples were collected to measure calcium and magnesium levels. Using these data we developed and tested both univariate and multivariate logistic regression models. We observed no significant differences in risk of CVDs between groups with desalinated seawater and fresh water intake. From multivariate logistic regression, we found that obesity (OR = 5.38, 95% CI: 1.05-27.45), physical activity (OR = 0.35, 95% CI: 0.16-0.75), hypertension (OR = 3.61, 95% CI: 1.58-8.25), alcohol consumption (OR = 2.57, 95% CI: 1.02-6.47), and irritability (OR = 4.30, 95% CI: 1.93-9.60) were associated with an increased risk of CVD. In this population, we found no association between desalinated seawater intake and CVDs; the incidence of CVDs was primarily related to lifestyle.

Formation and modeling of disinfection by-products in drinking water of six cities in China.

Water quality parameters including TOC, UV(254), pH, chlorine dosage, bromide concentration and disinfection by-products were measured in water samples from 41 water treatment plants of six selected cities in China. Chloroform, bromodichloromethane, dibromochloromethane, dichloroacetic acid and trichloroacetic acid were the major disinfection by-products in the drinking water of China. Bromoform and dibromoacetic acid were also detected in many water samples. Higher concentrations of trihalomethanes and haloacetic acids were measured in summer compared to winter. The geographical variations in DBPs showed that TTHM levels were higher in Zhengzhou and Tianjin than other selected cities. And the HAA5 levels were highest in Changsha and Tianjin. The modeling procedure that predicts disinfection by-products formation was studied and developed using artificial neural networks. The performance of the artificial neural networks model was excellent (r > 0.84).

Antibiotics in soil and water in China-a systematic review and source analysis.

With the high production and consumption of antibiotics in recent years due to increasing economic development and improving population health, China is facing serious antibiotic pollution in the environment, and it is becoming a significant threat to ecology and human health. This study explores the spatial distribution patterns of 65 antibiotics in soil, surface water and coastal water based on a systematic review. Potential emission sources of antibiotics are also analyzed using data extracted from the reviewed literature. The results suggest that China has very high antibiotic detection rates of 100%, 98.0% and 96.4% for soil, surface water and coastal water, respectively. Regions with high antibiotic levels are mainly located in Bohai Bay, including the Beijing‒Tianjin‒Hebei region, Liaoning and Shandong Provinces, and Yangtze River. Tetracyclines (TCs) and quinolones (QNs) are the dominant antibiotics observed in soil and are mainly attributed to the use of manure as fertilizer and the reuse of domestic wastewater. Sulfonamides (SAs), macrolides (MLs), TCs and QNs are the dominant antibiotics observed in surface water and are mainly attributed to aquaculture and the emission of domestic sewage. QNs are the dominant antibiotics observed in coastal water and are mainly attributed to marine cultivation. The detection frequencies and concentrations of TCs, QNs, SAs and MLs in both soil and water are much higher than those in other developed countries. Suggestions including restricting antibiotic usages in livestock farming and aquaculture, innovation of wastewater treatment technology to improve antibiotic removal rate, and establishing guidelines on antibiotic concentration for wastewater discharge and organic fertilizer are provided.

[Advances of study on assessing exposure to disinfection by-products in drinking water].

DBP exposure assessment issues were addressed. The basic definition to exposure assessment was introduced. Recommended ideal set of drinking water quality parameters to collect for each water treatment plant and specific disinfection by-products to be considered for future studies to adequately characterize DBP exposure were sum up. Previous studies and shortcoming of DBP exposure assessment were discussed and considered. Two examples of DBP exposure assessment were used to explain the progress and method of assessment in detail. Various disciplines to develop better approaches for measuring DBP exposure and greater collaboration of epidemiologists with water utilities and regulators should be encouraged in order to make regulatory monitoring data more useful for epidemiologic studies.

Risk assessment on disinfection by-products of drinking water of different water sources and disinfection processes.

The occurrences of trihalomethanes (THMs) and haloacetics (HAAs) in the water supply in Beijing and Canada were investigated. The concentrations of THMs and HAAs in Beijing and Canada were below the maximum contaminant levels specified by the USEPA and WHO standards. The multi-pathway risk assessment (assessed through oral ingestion, dermal absorption and inhalation exposure to drinking water) was used to assess the cancer risk and the hazard index of THMs and HAAs from fifteen waterworks in Beijing, China and three treatment plants using different disinfection processes in Canada. Residents in Beijing and residents who were served by three treatment plants using different disinfection processes in Canada had a higher risk of cancer through oral ingestion than through the other two pathways. The cancer risk resulted from disinfection by-products (DBPs) was 8.50E-05(for males), 9.25E-05(for females) in Beijing, China, while it was 1.18E-04, 1.44E-04 in Canada. The risk was higher when water treatment plants used surface water source than when they used ground water source and mixture water source in Beijing. The risk showed different changes in three treatment plants using different disinfection processes in Canada. The lifetime cancer risk for THMs followed the order: Plant 2>Plant 1>Plant 3. And, the lifetime cancer risk for HAAs was: Plant 1>Plant 2>Plant 3.

Petroleum hydrocarbon in surficial sediment from rivers and canals in Tianjin, China.

Surficial sediment samples were collected from three rivers and six canals in Tianjin, China and analyzed for petroleum hydrocarbons. Chemical compositions and distribution patterns, as well as possible sources, of the petroleum hydrocarbons in the sediments were discussed. A series of petroleum hydrocarbons, including n-alkanes, isoprenoid alkanes, anteiso-alkanes, alkyl hexamethylene, hopanes and steranes were detected in the samples. The concentration of petroleum hydrocarbons varied in a wide range of 0.072-3.000 mg g(-1) in the surficial sediment of the rivers and canals in Tianjin. In the samples studied, the total concentrations of petroleum hydrocarbons in the sediment samples from North Canal, South Canal, and G3 segment of South Sewage Canal were higher than those from Hai River, South Sewage Canal and North Sewage Canal. Accumulation of pollutants in the sediments from reaches close to urban area was also observed. The PHC spatial variability is mostly affected by many local inputs. The main sources of petroleum hydrocarbons in the sediment in Tianjin were considered to be petroleum importation and biochemical degradation of organisms, including cuticular of aquatic vegetation and algae.

[Study advance on haloacetic acids in drinking water].

Haloacetic acids (HAAs) in drinking water have attracted more and more attention of researchers due to their higher potential combination of chlorine, their carcinogenic and mutagenic effects and higher carcinogenic. The formation mechanism, analytical methods, the effects of many factors on HAAs formation such as precursor types, chlorine doses, pH, temperature, bromide, reaction time and seasonal change, toxicological character and the minimizing technology of HAAs in resent studies about HAAs are discussed in details in this paper. Further researches are still needed to clarify the formation mechanism of HAAs and find a feasible minimizing technology. New concerns including toxicological characters that correlate with human and other HAAs exposure routes besides oral ingestion (i.e., inhalation and dermal adsorption) should be put forward.

Emergency Response to and Preparedness for Extreme Weather Events and Environmental Changes in China.

China has achieved impressive rapid economic growth over the past 30 years but accompanied by significant extreme weather events and environmental changes caused by global change and overfast urbanization. Using the absolute hazards index (AHI), we assessed the spatial distribution patterns and related health effects of 4 major extreme natural disasters, including drought, floods (landslides, mudslides), hails, and typhoons from 2000 to 2011 at the provincial level in China. The results showed that (1) central and south China were the most affected by the 4 natural disasters, and north China suffered less; (2) the provinces with higher AHI suffered most from total death, missing people, collapse, and emergently relocated population; (3) the present health emergency response system to disasters in China mainly lacks a multidisciplinary approach. In the concluding section of this article, suggestions on preparedness and rapid response to extreme health events from environmental changes are proposed.

Hair Selenium Levels of School Children in Kashin-Beck Disease Endemic Areas in Tibet, China.

Previous studies have shown that the selenium (Se) deficiency is an important factor for the etiology of Kashin-Beck disease (KBD). Although KBD is presently controlled in most regions of China, it is still active in the Tibetan Plateau. The present study aimed to assess the nutritional status of selenium in school children by using the Se level in hair as a biomarker in KBD endemic areas of Lhasa in Tibet, China. Hair samples of 155 school children aged 6-15 years were collected in both KBD areas and non-KBD areas of Lhasa in 2013. The Se level in the hair samples was determined by inductive coupled plasma mass spectrometry (ICP-MS). The average concentration of Se in children's hair was 0.232 µg/g in KBD areas of Lhasa, which was significantly higher than the data reported decades ago. A significant difference in hair Se was observed between the boys (0.255 µg/g) and the girls (0.222 µg/g) in the studied KBD areas (P < 0.01, Mann-Whitney U test), but hair Se did not vary by age or region. School children in KBD endemic areas in Lhasa likely have improved Se status as a result of high Se content staple food substitution with the enforcement of Free Education Policy and Nutrition Improvement Plan in Tibet. Nevertheless, there were still 20.3 % of students with low Se status (hair Se <0.20 µg/g), which showed that Se status of school children was also partly affected by low Se environment in KBD endemic areas of Lhasa.