Distribution and sources of phthalate esters in the topsoils of Beijing,China

Phthalate esters in the topsoil samples collected from Beijing were determined by derivatization and gas chromatography–mass spectrometry techniques. The results showed that diethyl phthalate (DEP), diisobutyl phthalate ester (DIBP), dibutyl phthalate ester (DBP), dibutyl (2-ethyl hexyl) phthalate (DEHP), and dimethyl phthalate (DMP) were found in the topsoils. The total concentrations of the five phthalate esters varied from 2.30 to 24.71 μg g^?1. According to phthalate esters (PAEs) control standards in soil of the USA, the standard exceeding rates of DMP, DBP, and DEHP were 100 %, 100 %, and 4.84 % in soils of Beijing, respectively. The rate of DBP exceeding soil remediation standard was 12.9 %. Overall, concentrations of PAEs in Beijing were at a high level in China. The concentrations of DBP, DEHP, and DIBP were high, and the total concentrations of all the phthalate esters were higher in the areas with intensive human activities than in the other areas, which may be related to the use of phthalate compounds (such as the use of plastic products). The total and individual concentrations of phthalate compounds were relatively low in the areas that used plastic films compared with other samples due to the diffusion of atmospheric motion, categories, and amounts of plastic products and other factors. The greatest contributor may be the usage amount of plastic products in people’s daily lives.     

Investigating into composition,distribution, sources and health risk of phthalic acid esters in street dust of Xi’an City,Northwest China

Phthalic acid esters (PAEs) are widely used as plasticizers and in consumer products, which may enter the environment and present risks to human health. U.S. EPA classifies six PAEs as priority pollutants, which could be accumulated in street dust at the interface of atmosphere, biosphere and geosphere. This study collected a total of 58 street dust samples from Xi’an City in Northwest China and analyzed for concentrations of the priority PAEs. Composition, distribution, sources and health risk of the PAEs were further examined. All the priority PAEs were detected in the street dust. The concentrations of individual PAEs varied between not detected and 183.19 mg/kg. The sum of the 6 priority PAEs (∑6PAEs) ranged from 0.87 to 250.30 mg/kg with a mean of 40.48 mg/kg. The most abundant PAEs in the street dust were di-n-butyl phthalate and di (2-ethylhexyl) phthalate (DEHP). Higher concentrations of ∑6PAEs in the street dust were found in the south and west parts of Xi’an City as well as its urban center, which were possibly attributed to the prevailing northerly Asian winter monsoon. The PAEs in the street dust originated mainly from wide application of plasticizers as well as cosmetics and personal care products. The main pathways of human exposure to PAEs in the street dust were ingestion and dermal adsorption of dust particles. The non-cancer risk of human exposure to PAEs in the street dust was relatively low, while the risk to children was higher than that to adults. The cancer risk of human exposure to DEHP in the street dust was lower than the standard limit value of 10^?6.     

Occurrence and migration of microplastics and plasticizers in different wastewater and sludge treatment units in municipal wastewater treatment plant

● Reduce the quantifying MPs time by using Nile red staining. ● The removal rate of MPs and PAEs in wastewater and sludge were investigated. ● MPs and PAEs were firstly analyzed during thermal hydrolysis treatment. ● The removal of PAEs from wastewater and sludge was mainly biodegradation. Microplastics (MPs) and plasticizers, such as phthalate esters (PAEs), were frequently detected in municipal wastewater treatment plants (MWTP). Previous research mainly studied the removal of MPs and PAEs in wastewater. However, the occurrence of MPs and PAEs in the sludge was generally ignored. To comprehensively investigate the occurrence and the migration behaviors of MPs and PAEs in MWTP, a series of representative parameters including the number, size, color, shape of MPs, and the concentrations of PAEs in wastewater and sludge were systematically investigated. In this study, the concentrations of MPs in the influent and effluent were 15.46±0.37 and 0.30±0.14 particles/L. The MP removal efficiency of 98.1% was achieved and about 73.8% of MPs were accumulated in the sludge in the MWTP. The numbers of MPs in the sludge before and after digestion were 4.40±0.14 and 0.31±0.01 particles/g (dry sludge), respectively. Fourier Transform Infrared Spectroscopy (ATR FT-IR) analysis showed that the main types of MPs were polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), and polystyrene (PS). Six PAEs, including phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), ortho dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), and bis(2-ethyl) hexyl phthalate (DEHP), were detected in the MWTP. The concentrations of total PAEs (ΣPAEs) in the influent and effluent were 76.66 and 6.28 µg/L, respectively. The concentrations of ΣPAEs in the sludge before and after digestion were 152.64 and 31.70 µg/g, respectively. In the process of thermal hydrolysis, the number and size of MPs decreased accompanied by the increase of the plasticizer concentration.     

塑料增塑剂对凡纳滨对虾存活、生长和免疫的影响(Effects of Plastic Plasticizers on Survival, Growth and Immune Factors of Litopenaeus vannamei)

研究了塑料增塑剂邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二辛酯(DOP)对凡纳滨对虾(Litopenaeus vannamei)存活、生长和免疫的影响.96h急性毒性实验表明,在助溶剂Tween20的安全浓度范围内,随着DMP、DEP、DBP和DOP水平的升高,凡纳滨对虾存活率呈下降趋势,24h、48h、72h和96h的LC50分别为40.33、35.29、25.48、19.14mg·L-1,30.52、23.45、16.96、15.38mg·L-1,7.51、6.97、6.57、6.06mg·L-1和6.85、5.87、5.01、4.47mg·L-1;DMP、DEP、DBP和DOP对凡纳滨对虾的安全浓度随塑料增塑剂碳链的增加呈下降趋势,分别为8.11、4.15、1.80和1.29mg·L-1.90d慢性毒性实验表明,凡纳滨对虾存活率、特定生长率、血清蛋白含量、血清酚氧化酶和超氧化物歧化酶活性均以对照组和0.0400mg·L-1助溶剂Tween20处理组最高,而且显著高于1/100倍DMP、DEP、DBP和DOP安全浓度处理组(p<0.05).     

邻苯二甲酸二甲酯在离体人红细胞内的分布和含量研究

邻苯二甲酸酯类污染物(PAEs)在环境中普遍存在,可沿食物链富集,危害人体健康。本文利用荧光光谱法和高效液相色谱法(HPLC)探究了邻苯二甲酸二甲酯(DMP)在离体人红细胞内的分布情况。结果表明,红细胞在310 nm、490 nm和609nm处各具有一个荧光特征峰,其来源分别为:红细胞内的蛋白;还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)、黄素腺嘌呤二核苷酸(FAD)和膜脂;锌卟啉和原卟啉。DMP染毒后,310 nm处的荧光峰出现明显下降,其原因为进入红细胞内的DMP与蛋白发生了结合;490 nm和609 nm处的荧光峰变化很小。高效液相色谱(HPLC)实验结果表明,DMP能透过红细胞膜进入细胞内部,其进入量随暴露量增加而增加,进入量和暴露量的比值随暴露量增加而减少。上述研究成果能加深对PAEs在血液运输过程中与红细胞毒性作用的理解,可为PAEs的危险性评估和相关疾病预防提供数据参考。     

日常衣物中的邻苯二甲酸酯污染及其人体暴露风险

邻苯二甲酸酯(PAEs)作为一类内分泌干扰物,被广泛应用于工业生产。为了查明日常衣物中PAEs的污染状况,并评估其通过衣物的皮肤接触可能造成的人体暴露风险,本研究检测了日常生活中的新、旧衣服中7种典型PAEs的浓度,并通过实验模拟研究了衣料中PAEs向汗液的析出行为。结果表明,邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二异辛酯(DEHP)分别是旧衣服和新衣服中的代表性PAE。旧衣服中DEHP的浓度显著高于新衣服;婴儿衣服中DEHP的浓度高于成人衣服。穿着和清洗过程中的二次污染可能对衣服中的PAEs有显著影响,衣服材质可能是影响旧衣服中PAEs浓度的重要因素。汗液会导致衣物中的PAEs析出,从而明显增加PAEs的人体暴露风险。     

Garden soil and house dust as exposure media for lead uptake in the mining village of Stratoni,Greece

The relationships between two exposure media, garden soil and house dust, were studied for Pb uptake in Stratoni village in northern Greece, an industrial area of mining and processing of sulphide ore. Lead data for the two media were assessed in terms of total and bioaccessible content, measurement and geochemical variability, and mineralogical composition. It was found that total Pb was enriched in house dust samples by a factor of 2 on average. Total Pb concentration in soil samples had a maximum of 2,040 mg/kg and reached a maximum of 7,000 mg/kg in house dust samples. The estimated variability due to measurement uncertainty was dominated by the sampling process, and the proportion of sampling variance was greater for soil samples, indicating a higher degree of Pb heterogeneity in soil on the given spatial scale of sampling strata. Although the same general spatial trend was observed for both sampling media with decreasing Pb concentration by increasing distance from the ore-processing plant, Pb in dust samples displayed the highest concentrations within a 300–600-m zone from the ore-processing facility. The significant differences which were observed in Pb speciation between the studied media were explained by differences in mineralogical composition of outdoor soil and indoor dust. Lead-enriched Fe and Mn oxides predominated in soil samples while fine galena grains (<10–20 μm diameter) were the major Pb-bearing phase in dust samples. The integrated exposure uptake biokinetic model was used to predict the risk of elevated blood lead levels in children of Stratoni. Model prediction indicated an average probability of 61 % for blood-Pb to exceed 10 μg/dl. The results underline the importance of house dust in risk assessment and highlight the effect of outdoor and indoor conditions on the fate of Pb in the particular environment of Stratoni.     

南京市大气气溶胶中酞酸酯的分布特征

利用分级采样器采样 ,高效液相色谱检测 ,研究了南京市春夏秋冬四季六大功能区 (工业区 ,交通区 ,文化区 ,商业区 ,园林风景区和居民生活区 )大气气溶胶中的酞酸酯 .结果表明 :南京市大气气溶胶中检出的酞酸酯有 :邻苯二甲酸二甲酯 (DMP)、邻苯二甲酸二丁酯 (DBP)和邻苯二甲酸二辛酯 (DEHP) ,其含量随功能区和季节而变化 ,平均浓度具有工业区 >居民区 >交通区 >商业区 >文化区 >园林风景区和秋、冬季浓度高于春、夏季的分布特征     

Seasonal concentrations of lead in outdoor and indoor dust and blood of children in Riyadh,Saudi Arabia

Because detrimental effects of exposure to lead (Pb) on human health have been observed, we previously investigated concentrations of Pb in water supplies and blood of adult residents of Riyadh, Saudi Arabia. The objectives of the present study were to: (1) examine seasonal rates of deposition of Pb in dust in several areas of Riyadh city, (2) measure concentrations of Pb in both outdoor and indoor dust, (3) compare concentrations of Pb in dust in Riyadh with those reported for other cities, and (4) quantify Pb in blood of children living in Riyadh. Mean, monthly deposition of PB in outdoor dust was 4.7 × 10¹ ± 3.6 tons km^?2, with a mean Pb concentration of 2.4 × 10² ± 4.4 × 10¹ μg/g. Mean, monthly deposition of Pb in indoor dust was 2.7 ± 0.70 tons km^?2, with a mean concentration of 2.9 × 10¹ ± 1.5 × 10¹ μg Pb/g. There was a significant (P < 0.01) correlation between concentrations of Pb in outdoor and indoor dust. There was no correlation between concentrations of Pb in indoor dust and that in blood of children of Riyadh, whereas there was a weakly significant (P < 0.05) correlation between concentrations of Pb in outdoor dust and that in blood of children. The mean (±SD) concentration of Pb in blood of children in Riyadh was 5.2 ± 1.7, with a range of 1.7–1.6 × 10¹ μg/dl. Concentrations of Pb in blood of 17.8 % of children in Riyadh were greater than 10 μg/dl, which is the CDC’s level of concern.     

Bestimmung von Phthalsäureestern in Lebensmitteln, Frauenmilch, Hausstaub und Textilien

25 food samples, 5 mother’s milk specimens, 4 dust samples, and 16 textiles were analysed for phthalic acid esters. Phthalic acid esters were detected in all samples, with di (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) being the most abundant phthalates. Raw milk samples revealed average concentrations of total phthalate of 0.1 mg/kg. Retail milk did not contain higher loads than raw milk, even storing samples until their “best-before” date did not result in elevated levels. Skimmed milk was less contaminated than whole milk. The higher concentrations of DEHP and total phthalates in cream samples are due to their higher fat content. With concentrations up to 1.54 mg/kg, ground hazelnuts, almonds, and nutmeg in plastic packagings showed relatively high levels. In infant food, only traces of DEHP and DBP could be found while other phthalic acid esters were not detectable. The mother’s milk samples also exhibited only low amounts of approx. 0.1 mg/kg, thus indicating that there is no accumulation of phthalate esters in the human body. Extraordinarily high concentrations were found in dust samples; with the levels ranging from 300 to 5370 mg/kg and DEHP being the major compound. This leads to the conclusion that the air path must play a considerable role in the transfer of phthalic acid esters. As dust contains considerable amounts of textile fibres, textiles were also included in the investigation. The phthalic ester levels in the textile samples ranged from 3.42 to 34.44 mg/kg. Therefore, the high phthalate contaminations of dust cannot be explained by textile fibres.     

Chemical transformations of lead compounds under humid conditions: implications for bioaccessibility

This short communication documents chemical transformations caused by weathering of two Pb compounds that commonly occur in house dust. Chamber experiments were designed to simulate humid indoor environment conditions to determine whether Pb compounds undergo chemical transformations influencing bioaccessibility. Reference compounds of Pb metal (12 % bioaccessibility) and Pb sulfate (14 % bioaccessibility) were subjected to an oxygenated, humidified atmosphere in closed chambers for 4 months. X-ray diffraction (XRD) and X-ray absorption near-edge structure (XANES) spectroscopy were used to characterize the main Pb species, and the change in Pb bioaccessibility was determined using a simulated gastric acid digestion. At the end of the weathering period a small amount of Pb carbonate (9 % of total Pb) appeared in the Pb sulfate sample. Weathering of the Pb metal sample resulted in the formation of two compounds, hydrocerussite (Pb hydroxyl carbonate) and Pb oxide, in significant amounts (each accounted for 26 % of total Pb). The formation of highly bioaccessible Pb carbonate (73 % bioaccessibility), hydrocerussite (76 % bioaccessibility), and Pb oxide (67 % bioaccessibility) during weathering resulted in a measurable increase in the overall Pb bioaccessibility of both samples, which was significant (p = .002) in the case of the Pb metal sample. This study demonstrates that Pb compounds commonly found in indoor dust can ‘age’ into more bioaccessible forms under humid indoor conditions.     

Screening of phthalic acid esters in raw materials,premixes and feed additives

Phthalates are animal carcinogens and may cause death or tissue deformities. Samples of feedstuffs collected in 2005 and 2006 from industrial feed manufacturers in the Czech Republic were analysed for contamination with phthalic acid esters (PAEs), specifically di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP). Samples of feed additives, premixes and raw materials were collected (year 2005, n = 26). For soybean oil, the total volume of phthalates measured (DBP + DEHP) reached a level of 131.42 mg kg⁻¹; for rapeseed oil, fish meal and animal fats, the levels measured were 15.00, 7.96 and 58.87 mg kg⁻¹, respectively. The lowest level of DBP + DEHP was found in corn (2.03 mg kg⁻¹). Since phthalates were detected, samples of feed additives (n = 28) and raw materials (n = 28) were collected again in 2006. The highest levels of DBP + DEHP were found in raw materials containing fat. Phthalate levels in rapeseed oil samples ranged from 1.38 to 32.40 mg kg⁻¹ DBP + DEHP. For feed additives, contamination levels in vitamins and amino acids ranged from 0.06 to 3.15 and 1.76 to 4.52 mg kg⁻¹ DBP + DEHP, respectively. Here, we show that the levels of PAEs found in cereals such as wheat, barley and corn may be regarded as being alarmingly high, because cereals make up the largest proportion of compound feed of farm animals.     

Characterization of indoor dust from Brazil and evaluation of the cytotoxicity in A549 lung cells

Over the past decade, ambient air particulate matter (PM) has been clearly associated with adverse health effects. In Brazil, small and poor communities are exposed to indoor dust derived from both natural sources, identified as blowing soil dust, and anthropogenic particles from mining activities. This study investigates the physicochemical and mineralogical composition of indoor PM₁₀ dust samples collected in Minas Gerais, Brazil, and evaluates its cytotoxicity and inflammatory potential. The mean PM₁₀ mass concentration was 206 μg/m³. The high dust concentration in the interior of the residences is strongly related to blowing soil dust. The chemical and mineralogical compositions were determined by ICP-OES and XRD, and the most prominent minerals were clays, Fe-oxide, quartz, feldspars, Al(hydr)oxides, zeolites, and anatase, containing the transition metals Fe, Cr, V, Ni, Cu, Zn, Ti, and Mn as well as the metalloid As. The indoor dust samples presented a low water solubility of about 6 %. In vitro experiments were carried out with human lung alveolar carcinoma cells (A549) to study the toxicological effects. The influence of the PM₁₀ dust samples on cell viability, intracellular formation of reactive oxygen species (ROS), and release of the pro-inflammatory cytokine IL-8 was analysed. The indoor dust showed little effects on alamarBlue reduction indicating unaltered mitochondrial activity. However, significant cell membrane damage, ROS production, and IL-8 release were detected in dependence of dose and time. This study will support the implementation of mitigation actions in the investigated area in Brazil.     

天然水中有机污染物的生物降解模拟实验方法

本文系统地介绍了天然水体中有机污染物生物降解实验室模拟的建立原则、方法和分类，并以有机污染物邻苯二甲酸二甲酯（ＤＭＰ）和二乙酯（ＤＥＰ）为例，介绍了生物降解模拟实验过程。     

Resource utilization of typical biomass wastes as biochars in removing plasticizer diethyl phthalate from water: characterization and adsorption mechanisms

● Six largely produced agricultural biomass wastes were pyrolyzed into biochars. ● Feedstock type significantly determined physiochemical properties of biochars. ● The biochars showed powerful adsorption capabilities to Plasticizer DEP. ● Giant reed biochar with higher DEP adsorption was a prominent sorbent. Plastic pollution as a global environmental issue has become a research hotspot, among which the removal of inherent plasticizer (e.g., phthalic acid esters, PAEs) received increasing attention. However, the effects of biochars derived from different feedstocks on the adsorption of PAEs are poorly understood. Thus, the characteristics of biochars derived from six largely produced biomass wastes in China at 400 °C, as well as their performance in adsorption of diethyl phthalate (DEP), one of frequently detected PAEs in aqueous environment, were investigated. The results indicated that the variation in feedstock type showed significant changes in the properties (e.g., porosity, specific surface area, surface functional groups) of biochars, which affected DEP adsorption and desorption. Pseudo-second order and Freundlich models fitted the adsorption data well, and adsorption mechanisms mainly included hydrophobic effect, followed by micropore filling, hydrogen bonding, and π-π EDA interactions. Adsorption thermodynamics revealed that the adsorption was a spontaneous and exothermic the adsorption capacities of DEP on these biochars slightly decreased with the increasing pH but increased with the increasing ionic strength. Among these biochars, the giant reed biochar with relatively higher DEP adsorption and low desorption exhibited the great efficiency for DEP removal as an environment-friendly sorbent. These results highlighted the significant roles of micropore filling and hydrogen bond in determining adsorption capacity of designed biochars prepared from selecting suitable agricultural straws and wetland plant waste to typical plasticizer. The findings are useful for producing designed biochars from different biomass wastes for plasticizer pollution control.     

Spatial distributions,source apportionment and ecological risk of SVOCs in water and sediment from Xijiang River,Pearl River Delta

Xijiang River is an important drinking water source in Guangxi Province, China. Along the Xijiang River and surrounding tributary, the pollution profile of three important groups of semi-volatile organic compounds, including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and phthalate esters (PAEs), was analyzed. Relatively low levels of PAHs (64–3.7 × 10² ng L^?1) and OCPs (16–70 ng L^?1), but high levels of PAEs (7.9 × 10²–6.8 × 10³ ng L^?1) occurred in the water. Comparatively, low levels of OCPs (39–1.8 × 10² ng g^?1) and PAEs (21–81 ng g^?1), but high levels of PAHs (41–1.1 × 10³ ng g^?1) were found in sediment. Principal component analyses for source identification indicated petroleum-derived residues or coal and biomass combustion, and vehicular emission was the main sources for PAHs. The OCPs sources of each category were almost independent, whereas the new input of HCHs and p,p′-DDTs probably existed in some areas. PAEs were mainly originated from personal care products of urban sewage, plastic and other industrial sources. Ecological risk through the risk quotient analysis indicated a small or significant potential adverse effect on fish, daphnia and green algae. Nevertheless, the integrated risk of all pollutants should be taken into account in future study.     

Risk remaining from fine particle contaminants after vacuum cleaning of hard floor surfaces

In the indoor environment, settled surface dust often functions as a reservoir of hazardous particulate contaminants. In many circumstances, a major contributing source to the dust pool is exterior soil. Young children are particularly susceptible to exposure to both outdoor derived soil and indoor derived dust present in the indoor dust pool. This is because early in life the exploratory activities of the infant are dominated by touching and mouthing behavior. Inadvertent exposure to dust through mouth contact and hand-to-mouth activity is an inevitable consequence of infant development. Clean-up of indoor dust is, in many circumstances, critically important in efforts to minimize pediatric exposure. In this study, we examine the efficiency of vacuum cleaner removal of footwear-deposited soil on vinyl floor tiles. The study utilized a 5 × 10 foot (c. 152.5 × 305 cm) test surface composed of 1-foot-square (c. 30.5 × 30.5 cm) vinyl floor tiles. A composite test soil with moderately elevated levels of certain elements (e.g., Pb) was repeatedly introduced onto the floor surface by footwear track-on. The deposited soil was subsequently periodically removed from randomly selected tiles using a domestic vacuum cleaner. The mass and loading of soil elements on the tiles following vacuuming were determined both by wet wipe collection and by subsequent chemical analysis. It was found that vacuum cleaner removal eliminated much of the soil mass from the floor tiles. However, a small percentage of the mass was not removed and a portion of this residual mass could be picked up by moistened hand-lifts. Furthermore, although the post-vacuuming tile soil mass was sizably reduced, for some elements (notably Pb) the concentration in the residual soil was increased. We interpret this increased metal concentration to be a particle size effect with smaller particles (with a proportionately higher metal content) remaining in situ after vacuuming.     

Potentially harmful elements in house dust from Estarreja,Portugal: characterization and genotoxicity of the bioaccessible fraction

Due to their behavioral characteristics, young children are vulnerable to the ingestion of indoor dust, often contaminated with chemicals that are potentially harmful. Exposure to potentially harmful elements (PHEs) is currently exacerbated by their widespread use in several industrial, agricultural, domestic and technological applications. PHEs cause adverse health effects on immune and nervous systems and can lead to cancer development via genotoxic mechanisms. The present study is an integrated approach that aims at assessing the genotoxicity of bioaccessible PHEs following ingestion of contaminated house dust. A multidisciplinary methodology associating chemical characterization of five house dust samples, extraction of the bioaccessible PHEs in gastric extracts by the unified BARGE method, determination of the bioaccessible fraction and in vitro genotoxicity of gastric extracts in adenocarcinoma gastric human (AGS) cells was developed. The five gastric extracts induced dose-dependent genotoxicity in AGS cells. Copper (bioaccessible concentration up to 111 mg/kg) was probably the prevalent PHE inducing primary DNA damage (up to 5.1-fold increase in tail DNA at 0.53 g/l of gastric extract). Lead (bioaccessible concentration up to 245 mg/kg) was the most prevalent PHE inducing chromosome-damaging effects (r = 0.55; p < 0.001 for micronucleated cells induction). The association of principal component analysis and Spearman’s correlations was decisive to understand the chromosome-damaging properties of the bioaccessible PHEs in AGS cells. This methodology could be used on a larger-scale study to provide useful information for science-based decision-making in regulatory policies, and a better estimation of human exposure and associated health risks.     

Polybrominated diphenyl ethers in plastic products,indoor dust,sediment and fish from informal e-waste recycling sites in Vietnam: a comprehensive assessment of contamination,accumulation pattern,emissions, and human exposure

Residue concentrations of polybrominated diphenyl ethers (PBDEs) in different kinds of samples including consumer products, indoor dust, sediment and fish collected from two e-waste recycling sites, and some industrial, urban and suburban areas in Vietnam were determined to provide a comprehensive assessment of the contamination levels, accumulation pattern, emission potential and human exposure through dust ingestion and fish consumption. There was a large variation of PBDE levels in plastic parts of obsolete electronic equipment (from 1730 to 97,300 ng/g), which is a common result observed in consumer plastic products reported elsewhere. PBDE levels in indoor dust samples collected from e-waste recycling sites ranged from 250 to 8740 ng/g, which were markedly higher than those in industrial areas and household offices. Emission rate of PBDEs from plastic parts of disposed electronic equipment to dust was estimated to be in a range from 3.4 × 10^?7 to 1.2 × 10^?5 (year^?1) for total PBDEs and from 2.9 × 10^?7 to 7.2 × 10^?6 (year^?1) for BDE-209. Some fish species collected from ponds in e-waste recycling villages contained elevated levels of PBDEs, especially BDE-209, which were markedly higher than those in fish previously reported. Overall, levels and patterns of PBDE accumulation in different kinds of samples suggest significant emission from e-waste sites and that these areas are potential sources of PBDE contamination. Intakes of PBDEs via fish consumption were generally higher than those estimated through dust ingestion. Intake of BDE-99 and BDE-209 through dust ingestion contributes a large proportion due to higher concentrations in dust and fish. Body weight normalized daily intake through dust ingestion estimated for the e-waste recycling sites (0.10–3.46 ng/day/kg body wt.) were in a high range as compared to those reported in other countries. Our results highlight the potential releases of PBDEs from informal recycling activities and the high degree of human exposure and suggest the need for continuous investigations on environmental pollution and toxic impacts of e-waste-related hazardous chemicals.     

Abiotic association of phthalic acid esters with humic acid of a sludge landfill

The abiotic association between phthalic acid esters (PAEs) and humic substances (HS) in sludge landfill plays an important role in the fate and stability of PAEs. An equilibrium dialysis combined with ¹⁴C-labeling was used to study the abiotic association of two abundant PAEs (diethyl phthalate and di-n-butyl phthalate) with humic acid (HA) isolated from a sludge landfill with different stabilization times and different molecular weights. Elemental analysis and Fourier Transform Infrared Spectrophotometer (FTIR) suggested that high K _A value of HA was related to the high aromatic content and large molecular weight of HA. The results indicated that the association strength of PAEs with HA depended on both the properties of the PAEs and the characteristics of HA. The K _A values of the association were strongly dependent on solution pH, and decreased dramatically as the pH was increased from 3.0 to 9.0. The results suggested that nonspecific hydrophobic interaction between PAEs and HA was the main contributor to the association of the PAEs with HA. The interactive hydrogen-bonds between the HA and the PAEs molecules may also be involved in the association.