Heavy metals and pesticides in anuran spawn and tadpoles,water, and sediment

High concentrations of metals (cadmium, copper, lead, and zinc) and of lindane were measured in the sediment and in the spawn and tadpoles of Bufo bufo, Rana dalmatina, and Rana ridibunda from two Austrian locations. Residues in spawn suggest maternal transfer. Increase of the metal concentrations from spawn to advanced tadpole stage is explained by the larval microphaguous feeding habits which cause high exposition of the tadpoles to substances concentrating in sediments and suspended particles. Metal and pesticide concentrations in spawn and tadpoles are toxic to various other aquatic organisms and are furthermore considered to be potentially hazardous to the anurans themselves. The results are conform with world‐wide observations of contamination of anuran larvae with heavy metals, and prove the significance of non‐point source chemical exposure due to allochthonous toxicant input by wind load and precipitation.     

长江下游表层沉积物中有机氯农药的残留状况及风险评价

2005年3—4月在长江下游安庆段—南通段共采集表层沉积物样品28个,使用加速溶剂萃取、气相色谱/质谱法测定了样品中的有机氯农药(OCPs),包括六氯苯(HCB)、氯丹、滴滴涕(DDTs)、艾氏剂、狄氏剂、异狄氏剂、七氯和灭蚁灵等14种目标化合物. 结果表明:长江下游表层沉积物中的HCB和DDTs的检出率都为100%,DDTs是样品中OCPs的主要组分,其残留以降解代谢产物DDD和DDE为主. w(HCB)平均值为3.240 μg/kg (0.048～30.300 μg/kg),w(DDTs)平均值为8.100 μg/kg(0.336～32.830 μg/kg). 在长江下游不同采样点的OCPs含量差异很大,部分支流入江口和城市排污口附近样品中的w(DDTs)或w(HCB)出现高值. 沉积物中DDTs的来源主要与农用土壤风化流失和上游沉积物迁移、输送有关. 与沉积物风险评估值对比,长江下游表层沉积物中的DDTs存在一定的生态风险.      

急性毒性藻红外测试中联合作用的评价方法（Evaluation Method for Combined Toxicity Effects in the Measure of Alage Infrared Radiation for Acute Toxicity）

藻红外测试中联合作用的评价方法是急性毒性藻红外测试法的重要组成,为建立其评价方法,用敏感藻和重金属、有机药品、农药开展了探索性实验.首先确定联合作用系数θ的计算式和总均偏差系数f,用其构建联合偏差系数法;再用实验得到的f=0.06调整相加作用的θ理论值(θ=1),联合偏差系数θi分别在大于、等于、小于1+0.06或1-0.06时,评价联合作用类型;最后进行二元药品对敏感藻联合作用的验证实验,验证联合偏差系数法的可行性.结果发现,4种重金属6种混合对短线脆杆藻(Fragilaria brevistriata)的联合作用为:3次拮抗作用,2次独立作用,1次相加作用;4种有机药品6种混合对羊角月牙藻(Selenastrum capricornutum)的联合作用为:2次协同作用,3次独立作用,1次拮抗作用;8种农药12种混合对水华鱼腥藻、纤细裸藻的联合作用为:9次拮抗作用,3次独立作用;一组验证实验包括藻液加药、测试、计算和评价,共需要60min,而用光密度、细胞数、叶绿素含量、细胞干重作为测试指标进行藻类急性毒性实验,需要24h～96h.对验证结果分析可知,用所构建的联合偏差系数法评价二元药品对敏感藻的联合作用,具有可行、快速、简便的优势.     

蔬菜水果中的新烟碱类农药残留量与人群摄食暴露健康风险评价

新烟碱类农药是目前被广泛用于农业中的一类作用独特、高效广谱的内吸性杀虫剂,它们在蔬菜水果中的残留对人体健康构成威胁。本研究目的是查明北京市场上蔬菜水果中不同新烟碱类农药的残留量,并对人群摄食暴露健康风险进行评估。从北京市场上采集49种蔬菜和24种水果,采用Qu ECh ERS–高效液相色谱串联质谱(HPLC-MS/MS)法测定蔬菜水果中9种新烟碱类农药的含量。利用测得数据和中国居民膳食结构调查资料,采用蒙特卡罗模拟方法计算了不同年龄段人群的日均经口摄入暴露量的概率分布,并采用商值法计算了新烟碱类农药的非致癌风险。结果显示新烟碱类农药普遍存在于北京市场上的蔬菜水果中。49种蔬菜样品中检出7种新烟碱类农药,其中吡虫啉、啶虫脒和噻虫嗪检出率均达100%,噻虫胺、烯啶虫胺、噻虫啉和呋虫胺的检出率分别为47%、14%、10%和4%。24种水果样品中检出5种新烟碱类农药,其中吡虫啉和啶虫脒的检出率均达100%,噻虫嗪、噻虫胺和噻虫啉的检出率分别为54%、13%和4%。不同新烟碱类农药在蔬菜水果中的含量范围为0.01 ng·g~(-1)~126 ng·g~(-1),均未超过我国食品安全国家标准或美国联邦管理条例中的限量值。小部分(约3%)人群因摄食蔬菜水果暴露于新烟碱类农药的非致癌风险商值大于0.1。新烟碱类农药在蔬菜水果中普遍存在,对人体健康有潜在的风险。     

岩溶区不同水体有机氯农药对比研究

为研究岩溶区地下水、地表水之间有机氯农药的差异,用气相色谱-微池电子捕获检测器(GC-μECD)分析了水中OCPs含量.结果表明:研究区水样中有机氯农药检出率达100%.OCPs浓度范围32.13~319.53ng/L,均值为134.17ng/L.OCPs浓度季节差异明显,枯水期高于丰水期.水井(sj)中OCPs,DDTs、HCHs浓度均大于水池(sc).通过采样点间的对比可知,雨季水池、水井间OCPs含量相当,旱季水池小于水井.水池、水井间DDTs、HCHs对比没有明显的季节性,表现为水池的DDTs含量小于水井,但HCHs含量大于水井.水井中的OCPs、DDTs、HCHs的最小值与水池相比均表现出了滞后性.地表水与地下水有机氯农药表现出的差异,是由于两采样点的环境不同.通过比值法得出HCHs来自于混合源,地表水的比值更能准确的反映出HCHs的来源.DDTs可能来自于混合DDTs,且为历史残留,降解环境为好氧环境.水井中DDTs、HCHs百分比组成由于土壤的影响发生了变化.     

五种底栖动物对优控污染物的敏感性评价

参照美国水生生物基准技术指南以及欧盟、美国和中国优控污染物名录,搜集、筛选了伸展摇蚊、日本沼虾、河蚬、霍甫水丝蚓和泥鳅等5种代表性淡水底栖动物的优控污染物生物毒性数据,通过数据分析,筛选出对淡水底栖动物毒性最大的10种优控污染物,主要包括有机氯农药和重金属两大类.对筛选得到的10种优控污染物的物种敏感度分布进行了分析,结果表明伸展摇蚊与泥鳅对有机氯农药较为敏感,具有作为相关农药污染的指示生物以及水质基准研究的受试生物的潜力.     

Sediment quality assessment of Beasley Lake: bioaccumulation and effects of pesticides in Hyalella azteca

Beasley Lake is a Conservation Effects Assessment Program (CEAP) watershed in the intensively cultivated Mississippi Delta, USA. Lake sediment quality at three sites was evaluated in 2004 and 2008 for biological impairment and uptake (animal tissue pesticide residues) from 14 pesticides and three metabolites using Hyalella azteca (Saussure). Eleven pesticides and three metabolites were detected in sediment among the three sites in 2004 and all 17 compounds examined were detected among the three sites in 2008, with the herbicide atrazine having the greatest concentrations. Twenty-eight-day H. azteca survival and growth (mg w/w) indicated no survival effects at any site for either year, but growth impairment occurred in H. azteca exposed to sediments in 2004, whereas growth enhancement occurred in H. azteca exposed to sediments at one site in 2008. Pesticides observed in animal tissue pesticide residues occurred more frequently and in greater concentrations in 2004 compared with 2008. Thirteen pesticides were detected in animal tissue pesticide residues in 2004, with chlorpyrifos occurring in the greatest concentrations, and six pesticides were detected in 2008, with p,p′-DDT occurring in the greatest concentrations. H. azteca tissue pesticide residues of seven pesticides, two herbicides, three insecticides, one insecticide metabolite, and p,p′-DDT, were associated with growth.     

Renal lesions in Greenland sledge dogs ( Canis familiaris ) exposed to a natural dietary cocktail of persistent organic pollutants

Persistent organic pollutants such as Polychlorinated biphenyls (PCB) and dichloro diphenyl trichloroethane (DDT) are known to exert various adverse health effects in wildlife mammals. The impact from dietary intake of minke whale (Balaenoptera acutorostrata) blubber high in organohalogen and other chemical contaminants on renal morphology and function was investigated via a controlled study on West Greenland sledge dogs (Canis familiaris). Our results showed significantly higher frequencies of glomerular, tubular, and interstitial lesions in the exposed group. Furthermore, higher urine protein?:?creatinine ratio and plasma urea levels were found in the exposed group, which indicated a negative impact on kidney function via tubular and glomerular dysfunctions. The lesions were similar to those observed in top predator marine species–such as seals and polar bears–and humans exposed via diet to persistent environmental pollutants. The lesions may have impacts on the overall health of these animals. It is reasonable to suggest that chronic exposure to organic pollutants via a country diet of high trophic level marine organisms may have an impact on renal morphology and function in Arctic apex predators in general as well as Inuit people.     

Lifestyle and polybrominated diphenyl ethers in human milk in the United States: A pilot study

Polybrominated diphenyl ethers (PBDE) are a class of brominated flame retardants with some congeners having the ability to accumulate in body lipids. The incorporation of PBDE in consumer products found primarily in the indoor environment suggests that routes of exposure include inhalation of indoor air and contact with indoor dust. The purpose of this study was to test the hypothesis that lifestyle factors, and in particular the proximity and use of products likely to contain PBDE in the indoor environment, are primarily responsible for levels of PBDE found in human milk. Human milk samples were taken from two populations of lactating women in the same geographic region of the United States: one “typical” of US suburban lifestyle, and the other practicing a traditional Amish lifestyle, which excludes many modern amenities containing PBDE, such as computers and televisions. For a subset of the cohort, persistent organic pesticides and polychlorinated biphenyls (PCB) were also measured in human milk samples. Despite the small number of participants, there is evidence suggestive of Amish women having lower PBDE concentrations in their milk. In addition, the nonsignificant differences in levels of PCBs and pesticides between the two groups of women as compared to the significant differences in levels of PBDE suggest an important route of exposure for PBDE other than diet. Information prepared for study participants is provided to initiate a dialogue on how to best communicate biomonitoring findings to study participants and to the public in general.     

Prevalence of organochlorine pesticide residues in groundwaters of Kasargod District,India

The Kasargod District is the northernmost district of Kerala State and is bound between the north latitudes 12°02′27″ and 12°47′35″ and east longitudes 74°51′54″ and 75°25′25″. The present study highlights the contamination levels of organochlorine pesticides in open wells of the Kasargod District from 2010 to 2011. Maximum contamination of organochlorine pesticides (OCP's) was observed for endosulfan followed by hexachlorobenzene (BHC). Contamination levels of α-endosulfan were higher at Panathur (58?µg?L^?1) and next to Periya (37?µg?L^?1) in the postmonsoon season of 2010. During premonsoon 2011, the residue levels of α-endosulfan were higher at Panathady (56?µg?L^?1) followed by Rajapuram (40?µg?L^?1). Contamination levels of the BHC isomers exhibit the order of γ-BHC?>?α-BHC?>?β‐BHC, showing that γ-BHC represents 62% of the total OCP residues in premonsoon 2010. Among the studied OCP's, concentration levels of DDT were below detection limit. Maximum concentrations of the sum of all OCP residues were observed at Mulleria and Cheemeni (premonsoon 2010), followed by Panathur and Periya (postmonsoon 2010), and lowest in Panathady and Rajapuram (premonsoon 2011). Residues of OCP's were lowest in Paettikundu and Cheravatur in all the three seasons.