Pollutants In Environmental Media Research Articles

A systematic review and meta-analysis of pollutants in environmental media.

Environmental pollutants are ubiquitous in our environmental media, resulting in detrimental impacts on both humans and the environment. An evidence-based review, particularly a systematic review and meta-analysis, performs a crucial function in assessing the pollution status of pollutants in environmental media at national and global scales. We selected and thoroughly investigated 76 papers focusing on systematic reviews and meta-analyses of contaminants in environmental media. The need to broaden the scope of studies was observed with an increase in the total number of publications, andthere were greater focuses on food safety, water pollution, biological pollution, and environmental risks. Furthermore, this review outlined the fundamental procedures involved in a systematic review and meta-analysis, including literature searching, screening of articles, study quality analysis, data extraction and synthesis, and meta-analysis. A meta-analysis typically comprises fixed- and/or random-effects meta-analysis, identifying and measuring heterogeneity, sensitivity analysis, publication bias, subgroup analysis, and meta-regression. We specifically explored the application of meta-analysis to assess the presence of contaminants in environmental media based on twodifferent pollutant categories, namely, non-biological and biological pollutants. The mean value is commonly utilized to assessthe pooled concentration of non-biological pollutants, while the prevalence serves as the effect sizeofbiological pollutants. Additionally, we summarized the innovative applications,frequent misuses, and problems encountered in systematic reviews and meta-analyses. Finally, we proposed several suggestions for future research endeavors.

Spatial Distribution of Heavy Metals and Pollution of Environmental Media Around a Used Lead-acid Battery Recycling Center in Ibadan, Nigeria.

Background.Heavy metals are usually present in trace amounts in various environmental media such as water, soil, and air, and many are poisonous to human health even at very low concentrations.Objectives.To assess the risk of heavy metal contamination of water, soil, and plants around a used lead acid battery (ULAB) recycling center in Ibadan, Nigeria.Methods.Environmental samples (water, soil, and plants) were collected using standard methods and concentrations of arsenic (As), cadmium (Cd), antimony (Sb), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) were determined using inductively coupled plasma-optical emission spectrometry at the International Institute of Tropical Agriculture, Ibadan, Nigeria.Results.The concentration of metals detected in water samples were higher than permissible limits at more than 50% of the sampling locations. In contrast, heavy metals in soil were within permissible limits. Most of the heavy metals except Pb were found to be present in the plant within permissible limits. Lead levels in water and plants from all locations exceeded the permissible limits. The contamination degree and pollution load index of water sources around the ULAB recycling center indicate a high degree of pollution of water sources with heavy metals, while soil samples were within the normal baseline levels. The transfer factor of Pb from soil to Amaranthus viridis was 1.92. This has implications for human health as the plant is often harvested and for sale in local markets as a source of food and medicine.Conclusions.The present study recommends improved technology for ULAB recycling and adequate treatment of effluent/runoff from recycling centers before discharge.Competing Interests.The authors declare no competing financial interests.

Urinary parabens in children from South China: Implications for human exposure and health risks

Parabens are extensively applied in cosmetics, drugs or food as preservatives and have become common pollutants in environmental media. However, data on human exposure to these chemicals is still limited, especially for children. This study aimed to investigate parabens in urine samples of children and to evaluate the cumulative risk of paraben exposure. Five short-chain parabens were measured in 255 urine samples collected from children in a kindergarten and elementary schools from South China. Methyl paraben (MeP), ethyl paraben (EtP) and n-propyl paraben (PrP) were widely detected in urine samples (detection rates > 94.9%), indicating their widespread exposure. The urinary median concentrations of MeP, EtP and PrP were 2.25, 0.33 and 0.50 μg/L, respectively. Significantly positive correlations (p < 0.01) were observed between MeP and PrP in urine, suggesting similar sources and/or metabolic pathways of these two chemicals. The median estimated daily intakes (EDIs) of parabens were determined to be 18.1 and 9.79 μg/kg-bw/day for kindergarten children and elementary school students, respectively. Estimation of human intake and exposure risks indicated potential risks of PrP exposure for elementary school students. This is the first study addressing paraben exposure in South China children.

A Review Of Researches On Biochar Adsorbing Organic Contaminants And Its Mechanism And Influence Factors

Biochar is a product in the anoxic conditions to the biomass pyrolysis. Because of its exquisite unique pore structure and surface chemical properties, the organic pollutants in environmental media have strong adsorption capacity, and thus affect the migration of pollutants and end-result. In recent years the biochar research on adsorption characteristics and mechanism of organic pollutants has become one of the research hotspots in the field of environmental science. This article mainly explains the mechanism of biochar adsorption to organic pollutants and the influence factors.

Spatiotemporal variability of polybrominated diphenyl ether concentration in atmospheric fine particles in Shenzhen, China

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmental media. However, little is known about PBDE levels in Shenzhen, a manufacturing center of electronic products. This study aimed to investigate spatiotemporal variability of PBDE concentration in atmospheric fine particles (PM2.5) and to estimate the daily inhalation exposure doses for local residents in Shenzhen, China. A total of 36 samples were collected and 8 PBDE compounds (BDE-28, 47, 99, 100, 153, 154, 183 and 209) were analyzed by isotope dilution high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). Mean concentrations of Σ8PBDEs and BDE-209 in PM2.5 in Shenzhen were 33.47 pg/m3 and 24.75 pg/m3, respectively, which were lower than those for other reported cities from China. The mean concentration of Σ8PBDEs was higher in the winter + spring than that in summer + autumn, and both concentrations of BDE-28 and BDE-47 in PM2.5 were significantly higher in winter + spring than those in summer + autumn. Among the 8 congeners, BDE-209 was predominant, accounting for 73.9% of the Σ8PBDEs concentrations. Traffic area, industrial area, residential area and discharge of electronic industries had significant positive influences on PBDE concentrations in PM2.5. Both vegetation area and water area were significantly negatively correlated with PBDE levels in PM2.5. Significantly negative correlation was also found between PBDE concentrations in PM2.5 and the relative humidity. The ranking of estimated inhalation exposure doses of PBDEs via PM2.5 inhalation were toddlers (1.74 pg/kg b.w./day) > children (1.33 pg/kg b.w./day) > adults (1.26 pg/kg b.w./day) > teenagers (0.64 pg/kg b.w./day), and toddlers had a highest risk to expose to PBDEs by PM2.5. To our knowledge, the present study is the first to reveal the spatiotemporal variability of PBDEs in PM2.5 of Shenzhen, China.

Urinary metabolites of organophosphate esters in children in South China: Concentrations, profiles and estimated daily intake.

Organophosphate esters (OPEs) are widely used in household products as flame retardants or plasticizers and have become ubiquitous pollutants in environmental media. However, little is known about OPE metabolites in humans, especially in children. In this study, eight OPE metabolites were measured in 411 urine samples collected from 6 to 14-year-old children in South China. Bis(2-chloroethyl) phosphate (BCEP), bis(1-chloro-2-propyl) phosphate (BCIPP) and diphenyl phosphate (DPHP) were the dominant OPE metabolites, and their median concentrations were 1.04, 0.15 and 0.28 μg/L, respectively. The levels of urinary OPE metabolites in the present study were much lower than those in participants from other countries, with the exception of BCEP, suggesting widespread exposure to tris(2-chlorethyl) phosphate (TCEP, the parent chemical of BCEP) in South China. No significant difference in the concentrations of any of the OPE metabolites was observed between males and females (p > .05). Significant negative correlations were observed between age and BCEP, BCIPP, bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), di-o-cresyl phosphate (DoCP) and di-p-cresyl phosphate (DpCP) (DCP), or DPHP (p < .05). Pearson correlation coefficients between urinary OPE metabolites indicated multiple sources and OPE exposure pathways in children. The estimated daily intake suggested that children in South China have a relatively high exposure level to TCEP. To the best of our knowledge, this is the first study to report the urinary levels of OPE metabolites in Chinese children.

Hexabromocyclododecanes in breast milk from residents in Shenzhen, China: Implications for infant exposure

Hexabromocyclododecanes (HBCDs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmental media. However, little is known about HBCD exposure for humans, especially in China. This study aimed to investigate the levels and profiles of hexabromocyclododecanes (HBCDs) in human breast milk and to estimate the daily HBCD intake for infants in Shenzhen, China. Levels of the HBCD diastereoisomers α-, β-, and γ-HBCD in 180 breast milk samples collected from primiparas in Shenzhen were measured. The concentrations of α-, β-, and γ-HBCD (ΣHBCDs) ranged within 0.103–15.1ng/g lipid and had a median of 1.82ng/g lipid. ΣHBCDs levels in milk in the present study are comparable to those in milk from other countries and regions but are markedly higher than those for most populations in other regions of China. Among the diastereoisomers, α-HBCD was predominant, accounting for 97.6% of the concentration of ΣHBCDs. The estimated daily intake of ΣHBCDs via breast milk for infants in Shenzhen ranged from 0.481 to 100ng/kgbw/day with a median of 8.40ng/kgbw/day, however, which was unlikely to raises a health concern based on the margin of exposure (MOE) approach. The duration of residence was found to have a significant positive correlation with the HBCD levels in the human breast milk (p<0.05). To our knowledge, this is the first report on HBCD levels in breast milk from Shenzhen residents.

Bioassay-directed identification of organic toxicants in water and sediment of Tai Lake, China

The government of China has invested large amounts of money and manpower into revision of water quality standards (WQS). Priority organic pollutants have been screened for WQS establishment using the potential hazard index method, however, some unsuspected chemicals that could cause adverse effects might have been ignored. A large number of chemicals exist in environment and there might be interactions between or among chemicals especially those with the same mode of action. Therefore, a toxicity-directed analysis, based on acute toxicity to Daphnia magna, was conducted for organic extracts of water and sediment from Tai Lake (Ch: Taihu) to determine toxicants responsible for adverse effects. Extracts of five of twelve samples of water and all extracts of sediment were acutely toxic. Based on toxic units, water from location L1 in July and sediments from locations L1 and L4 during several months would be expected to result in some toxicity. Twenty one (21) organophosphorus pesticides, 25 organophosphorus pesticides and 10 pyrethroids were detected in samples, extracts of which caused toxicity to D. magna. Chlorpyrifos and cyfluthrin were identified as predominant pollutants in organic extracts of sediments, accounting for up to 71% and 57% of bioassay-derived toxicity equivalents (BEQs), respectively. Chlorpyrifos was identified as the major contributor to toxicity of organic extracts of surface water, accounting for 71% to 83 % of BEQs. The putative causative agents were confirmed by use of three lines of evidence, including statistical correlation, addition of key pollutants or synergists. Greater attention should be paid to chlorpyrifos and cyfluthrin, neither of which is currently on the list of priority pollutants in China. Bioassay-directed analysis should be added for screening for the presence of priority organic pollutants in environmental media.

Background environmental pollution of the Eurasian continent

(1) The interest to studying pollution of environmental media on the background level has grown in the recent years. There arose a necessity to establish a specialized observational system for conducting observations of changes in the state of the environment, and of ecological consequences of pollution as well as to produce assessments of the current and predicted states. The realized program of background monitoring and first results of integrated background measurements have already been published. The paper presented illustrates time-and-space features of the background pollution of natural environmental media according to data from various background stations. (2) Long-term systematic measurements at the 'Borovoe' station (Kazakh SSR) commenced in 1976 have been supplemented with the results of the background pollution studies carried out in Berezinskyi, Caucasian, Central-Chernozem, Sary-Chelek, and Repetek Biosphere Reserves and in locations of the background stations in Hungary and Czechoslovakia. The data from the Hungarian and Czechoslovak stations were obtained during joint expeditions. Details are given in the relevant publications. (3) Ozone. Ozone measurements show the diurnal variation with the day-time maxima from 35 up to 160 μg m(-3). The correlation between day-time and nocturnal concentrations is a good indicator of the anthropogenic effect. (4) Sulphur dioxide and sulphates. The annual variation of sulphur dioxide characterised by winter maximum and summer minimum indicates the direct dependence on the amount of fuel burnt in the given region. Mean values of the sulphur dioxide content in the surface layer of the atmosphere correlates with the extent of the region urbanization and varies within 0.2-12.5 μg m(-3). The value of sulphur dioxide and sulphates correlation in the atmosphere is rather stable and varies within 0.18-0.37 μg m(-3). (5) Heavy metals. The annual cycle of the atmospheric content of lead, cadmium and arsenic is well expressed by winter maximum and summer minimum (which is opposite in case of mercury). As for lead and mercury, their annual variation is more distinct than that of cadmium and arsenic; their time-and-space variation is also more distinct. The content of these metals in the urbanized regions of Europe is 5 times higher than in Asia and the Caucasus. Atmospheric contents of arsenic and cadmium vary insignificantly from region to region. The content of all these metals in other environmental media (soil, water, vegetation) is of insignificant spatial variability. Observations in the Caucasian Biosphere Reserve showed minimum levels of the background atmospheric pollution: lead-16 μg m(-3), mercury-5 ng m(-3), arsenic-3.9 ng m(-3), cadmium-0.5 ng m(-3). (6) Organochloride pesticides. Concentrations of DDT and its metabolites and hexachlorocyclohexane isomers in the environmental media of European background regions are 3 times higher than those in Asia ('Borovoe'). (7) PAH. Atmospheric content of BaP has a well expressed annual variation with winter maximum; the difference between winter and summer periods reaches the magnitude of an order. Background concentrations in European regions (Hungary, Berzinskyi Biosphere Reserve) are noticeably higher than in Asia; the difference reaches 3-5 times. (8) Comparisons with literature data on the background pollution show that observational materials from the background monitoring stations supplement to a considerable extent, and extent, the current notions on the background pollution and show the effects of the man-made impact on the background regions.