Polybrominated diphenyl ethers in food and associated human daily intake assessment considering bioaccessibility measured by simulated gastrointestinal digestion

The concentrations of PBDEs in 299 vegetable and animal-based food samples of 31 species, collected in Shanghai, China, and the bioaccessibility of PBDEs in part of the samples were determined. The PBDE concentrations ranged from 0 to 1245.4 pg g⁻¹ with animal-based food containing more PBDEs than vegetables. The bioaccessibility of PBDEs, determined by a method simulating human gastrointestinal digestion process, were from 2.6% to 39.9% in vegetables, and from 5.2% to 105.3% in animal-based food. For animal-based food, good correlations were observed between the bioaccessibility of PBDEs and the fat content, thus the fat content in animal-based food was able to be used to estimate the bioaccessibility of PBDEs. The total daily intake of PBDEs via ingestion of vegetables and animal-based food for an average Shanghai resident was estimated as 13 235.7 and 13 668.0 pg d⁻¹, respectively, but the amounts available for human absorption were reduced to 2674.4 and 4316.6 pg d⁻¹ after the PBDE bioaccessibility was considered. Finally, the contributions of different food groups to the total daily intake of PBDEs were evaluated. The results revealed that, when not considering the bioaccessibility of PBDEs, vegetables were the leading contributor (49.2%), followed by fish (34.0%). However, the sequence was reversed after the PBDE bioaccessibility was taken into account. The results indicated that human exposure to PBDEs via food ingestion might have been significantly overestimated and the exposure assessment could be misleading if the bioaccessibility of PBDEs was not considered.     

Alterations in Carbohydrate Metabolism in Selected Tissues of Crab,Oziotelphusa Senex Senex (Fabricius) Under Fenvalerate-Induced Stress

Changes in carbohydrate metabolism in hepatopancreas and muscle of the crab, Oziotelphusa senex senex exposed to a sublethal concentration (0.2 ppm) of fenvalerate, a pyrethroid insecticide, were studied. the glycogen and total carbohydrate levels decreased significantly in the tissues of crab exposed to fenvalerate. an increase in phosphorylase ‘a’ and decrease in aldolase activity levels suggested increased glycogenolysis, and decreased glycolysis during fenvalerate toxicity. Krebs cycle enzymes such as NAD-isocitrate dehydrogenase, succinate dehydrogenase and malate dehydrogenase were decreased, suggesting reduced mitochondrial oxidative metabolism. Glucose-6-phosphate dehydrogenase activity was increased significantly, indicating enhanced oxidation of glucose through the hexose monophosphate shunt pathway. Lactate dehydrogenase activity was elevated indicating the development of anaerobic conditions at tissue level in the stressed crab. Cytochrome C oxidase and Mg2+ ATPase activity levels were also decreased, indicating the impaired energy synthesis and prevalence of energy crisis. These results suggest that fenvalerate has a profound effect on the glucose metabolism of crab.     

Pesticide residues intake of French adults under increased consumption of fresh fruits and vegetables – A theoretical study

The increase of fresh vegetable and fruit (FVF) intake could contribute to the prevention of obesity and several major pathologies and thus represents a major public health goal in industrial countries. Nutritional recommendations for increased consumption of FVF could lead to ingestion of unwanted amounts of pesticides. This study was undertaken to evaluate theoretical exposure of French adults to pesticide residues under increasing amounts of FVF intake. Balanced menus with 200 – 400 – 600 – 800 and 1200 g FVF/day were established. Amounts of active substances brought by every FVF vector, at the maximum residue level (MRL) were summed up to determine the intake for each active substance. Values were compared to the Acceptable Daily Intake (ADI) to point out any potential over exposure. A maximalistic approach was adopted and no reducing factor due to processing was taken into account. It was found that under minimal recommended consumption of fruit and vegetables (400 g/d), no active substance reached the ADI, but 18 vs 144 were over 10% of the ADI. Raising FVF to 600 g/d increased the number of active substances over 10 % of the ADI to 24, but again in no case was the ADI exceeded. Doubling the intake to 800 g/d gives values over the ADI for 2 active substances only (cyhexatin and thirame). It was concluded that the increase in fruit and vegetables up to 800 g per day should not expose adults over the ADIs for a majority of authorized pesticides. In this regard, residues levels of ten active substances in fruit and vegetables should deserve particular attention.     

北京市菜地土壤和蔬菜铬含量及其健康风险评估

对北京市97种蔬菜的345个蔬菜样品和54个菜地土壤中的铬含量进行了研究.结果表明,北京市菜地土壤中铬含量的含量范围、算术均值、中值、几何均值分别为25.4～86.3、44.5、42.2、43.4 mg·kg-1,均低于<土壤环境质量标准>中的蔬菜地土壤质量标准,但显著高于北京市土壤铬背景值.蔬菜铬的含量范围、算术均值和几何均值分别为0.4～1034、64.6、22.7μg·kg-1.叶菜类和根茎类蔬菜的铬平均含量显著高于特菜类,其它类型的蔬菜铬含量差异不显著.北京市本地产蔬菜和裸露地蔬菜的铬含量均分别显著高于市售外地产蔬菜和设施栽培蔬菜.甘蓝的铬富集系数较高,小白菜、云架豆和冬瓜次之,而西红柿、黄瓜、大葱、叶甜菜、萝卜、大白菜、茄子和辣椒和部分特菜等铬富集系数最低.北京市居民从蔬菜中摄入铬的量为每人50.5μg·d-1,目前已存在一定的潜在健康风险.     

果蔬罐头生产废水治理工程设计研究

采用接触氧化-SBR工艺对果蔬罐头生产废水进行治理,其工艺抗冲击负荷能力强,抗污泥膨胀性能较好,对水质水量变化的适应性强。本文对该公司废水来源及水质、废水处理工艺流程及其特点、主要构筑物及其设备参数、工程运行效果做出了详细的分析和讲解。试验研究表明,工艺运行稳定、出水水质较好,能够满足《污水综合排放标准》(GB 8978-1996)中的一级排放要求。     

Distribution of Metals in the Edible Plants Grown at Jajmau, Kanpur (India) Receiving Treated Tannery Wastewater: Relation with Physico-Chemical Properties of the Soil

The implications of metal contamination of agricultural soils due to long term irrigation with treated industrial wastewater and their subsequent accumulation in the vegetables/crops growing on such soils has been assessed in an area of industrial complex, Jajmau, Kanpur (India). Physico-chemical properties of the soil were also studied. The soil and vegetables/crops were sampled from an area of 2100 acre agricultural land and analyzed for physico-chemical properties and metal accumulation in different parts of the plants. The comparison of the data of physico-chemical properties of control and contaminated soil showed that salinity, electrical conductivity, available phosphorous, sodium and potassium content (both water soluble and exchangeable) were found high in contaminated soil. The analysis of plant available metal content in the soil showed the highest level of Fe, which ranged from 529.02 to 2615 μg g⁻¹ dw and lowest level of Ni (3.12 to 10.51 μg g⁻¹ dw). The analysis of the results revealed that accumulation of toxic metal Cr in leafy vegetables was found more than fruit bearing vegetables/crops. Thus, it is recommended that the leafy vegetables are unsuitable to grow in such contaminated sites. It is important to note that toxic metal, Ni was not detected in all the plants. The edible part of the vegetables (under ground) such as, garlic (19.27 μg g⁻¹ dw), potato (11.81 μg g⁻¹ dw) and turmeric (20.86 μg g⁻¹ dw) has accumulated lowest level of toxic metal, Cr than leafy and fruit bearing vegetables. In some fruit part of vegetables such as, bitter gourd, egg plant, jack tree, maize and okra, the accumulation of Cr was not detected and may be grown in this area.     

Heavy Metal Concentrations in Water, Sediments and Body Tissues of Red Worm (Tubifex spp.) Collected from Natural Habitats in Mumbai, India

Live feeds, especially Tubifex spp., which are collected from a wide variety of polluted habitats, are used by aquarium fish keepers in India. These habitats receive domestic sewage and industrial wastes from nearby residential and industrial areas. Reports of morbidity and mortality from aquarium fish culturists in and around Mumbai led to the present investigations on the ecology of these habitats with a view to assess the water quality, presence of heavy metals in the environment and their bioaccumulation in Tubifex worms, and to examine whether these habitats could be exploited to meet the demand of the industry. Six natural red worm (Tubifex spp.) collection centres in Mumbai and Thane districts of Maharashtra state in India constituting a major source of live Tubifex supply to aquarium fish industry were evaluated for pollution, heavy metal concentration in water, sediments and in the body tissues of Tubifex. Data revealed the presence of heavy metals in water and sediments at collection sites and bioaccumulation of cadmium, iron, lead, zinc and copper in body tissues of Tubifex worms. Cadmium ranged from 2.38 to 7.21 mg/kg, iron 671.9 to 5738 mg/kg, lead 14.95 to 33.49 mg/kg, zinc 60.20 to 166.60 mg/kg and copper 29.38 to 108.90 mg/kg of dry Tubifex worms. The study suggests that all the six collection sites are polluted and the red worms contaminated with heavy metals and hence, unfit for use in aquaria or feeding any variety of fish or crustaceans in the hatcheries.     

锌冶炼区菜地土壤和蔬菜重金属污染状况及风险评价

对黔西北地区某典型锌冶炼区菜地土壤和主要蔬菜进行取样调查,测定了土壤和蔬菜可食用部分Pb、Cd、Zn、Cu、As、Ni 6种重金属的含量,采用单项污染指数和综合污染指数法评价了土壤和蔬菜中重金属的污染状况,并分别采用潜在生态风险指数（RI）和目标危险系数法（THQ）评价了菜地土壤重金属污染的潜在生态风险和蔬菜中重金属对成人和青少年儿童的健康风险.结果表明,该区域菜地土壤已受到重金属的重度污染,且以Cd对综合指数的贡献最大,土壤Cd存在极强生态风险,研究区处于轻微、中等、强和很强的生态风险程度的采样点比例分别为2.0%、14.3%、35.7%和48.0%;在所采集的蔬菜样本中,土豆处于重度污染水平,芸豆处于中度污染水平;复合重金属健康风险指数评价结果表明,食用研究区域蔬菜对成人和青少年儿童健康产生负面影响的可能性很大.     

Distribution of PAHs in tissues of wetland plants and the surrounding sediments in the Chongming wetland, Shanghai, China

Polycyclic aromatic hydrocarbons (PAHs) concentrations were determined in sediments and three types of wetland plants collected from the intertidal flats in the Chongming wetland. The concentration of total PAHs in sediments ranged from 38.7 to 136.2 ng g⁻¹. Surface sediment concentrations were higher in regions with plant cover than in bare regions. Rhizome-layer sediments (56.8-102.4 ng g⁻¹) contained less PAHs than surface sediments (0-5 cm). Concentrations of PAHs in plant tissues ranged from 51.9 to 181.2 ng g⁻¹, with highest concentrations in the leaves of Scirpus. Most of the PAHs in the leaves and other plant tissues were low molecular weight compounds (LMW, 2-4 rings), and a similar distribution pattern of PAHs in different types of plants was also observed. Source analysis indicated that plants and sediments both came from pyrogenic sources, but plants had additional petroleum contamination. The low ratio of benzo[a]anthracene over chrysene suggests that the wetland PAHs came mainly from long-distance atmospheric transportation. Significant bioaccumulation of PAHs from the sediments into plants was not observed for high molecular weight PAHs (HMW, 5-6 rings) in Chongming wetland. The small RCFs (root concentration factor from sediments) for HMW PAHs and large RCFs for LMW PAHs suggested that roots accumulated LMW PAHs selectively from sediments in Chongming wetland.     

盆栽条件下常见蔬菜对污染土壤中铀的吸收

通过盆栽实验,研究了胡萝卜、生菜、马铃薯、豌豆4种蔬菜在人工铀污染土壤中的种植情况。结果表明蔬菜吸收铀的能力不同,相同条件下的4种蔬菜可食用部位中铀含量大小顺序为:土豆>生菜叶>胡萝卜>豌豆;平均铀含量分别为:0.26,0.25,0.11,0.09 mg/kg,且均为低铀富集作物。加入铀溶液的土壤所种植的蔬菜样品中铀含量相比对照组土壤均有所升高,但其铀含量未超过国家标准限值,处于安全水平。