番茄中77种农药残留检测及膳食暴露风险评估

目的 分析上海市地产番茄的农药残留情况,评估其在一般人群和4~6岁儿童中的膳食暴露风险。方法 采集上海市9个区86个生产种植主体的111份地产番茄样品,采用气相色谱-质谱联用法和液相色谱-质谱联用法对77种农药残留进行检测,并采用确定性评估模型对检出的农药残留进行膳食暴露风险评估。结果 在检测的111份番茄样品中,57份样品检出农药残留,整体检出率为51.35%,合格率为100%。共检出14种农药,以腐霉利、啶酰菌胺和霜霉威等为代表的杀菌剂为主,检出占比为64.29%。一般人群和4~6岁儿童的慢性膳食摄入风险分别为0.00124%~0.53251%和0.00266%~1.14138%,急性膳食摄入风险分别为0.04837%~4.26422%和0.17818%~15.59091%,均小于100%,膳食暴露风险处于可接受的范围。结论 上海市地产番茄的农药残留膳食暴露风险较低,不会对消费者产生健康危害。本研究可为上海市番茄生产的用药指导和质量安全监管提供数据支撑及参考依据。     

Current knowledge and recent developments in consumer exposure assessment of pesticides: A UK perspective

Techniques employed in the assessment of consumer exposure to pesticides are currently being reviewed in the UK. This is not a formal process as is happening in the USA. However, the advent of probabilistic approaches and sophisticated computer models has prompted regulators, industry and other stakeholders in the UK to recognize the need for refinements in the risk-assessment process. Sources of information and data necessary to explore such refinements are disparate. This review aims to collate the information to present a coherent picture of the current knowledge, the data available and the stakeholders involved. It can then be used as a resource with which to investigate further more specific issues. Although focussing on the UK, the European context is included and reference is made to US models and developments that should be investigated. Factors hampering progress include the lack of sufficient data on which to base quantitative analysis, especially in the residential pesticides sector, and lack of experience in using and interpreting probabilistic models. At present, such techniques are being approached with some caution in the UK and in Europe, although their utility for cumulative assessment is accepted. Communicating results to both risk managers and consumers will be a considerable challenge.     

Variability in pesticides residues the US experience

The evolution of US Environmental Protection Agency's (EPA) process for estimating potential health risks from pesticide residues in or on food is examined in light of changes in US Legislation and the variability of residue data and assumptions used to estimate dietary exposure. In the 86 years since enactment of the Insecticide Act, pesticide laws have become progressively more health-based. Passage of the 1996 Food Quality Protection Act (FQPA) requires EPA to place particular emphasis on assessing potential risk from pesticides to infants and children. Primary factors affecting the actual pesticide residues in food include frequency of application, percentage of crop treated, and the interval from treatment to harvest. Primary factors affecting the estimated pesticide residues in food include the source of the residue data, calculation techniques for non-detected residues, and the availability of data reflecting post-harvest treatments. Risk assessors must thoroughly consider these factors when assessing dietary risk to pesticides. Risk managers will need to consider these factors as a means of mitigating dietary risk from pesticides.     

Probabilistic assessment of the cumulative dietary acute exposure of the population of Denmark to organophosphorus and carbamate pesticides

Organophosphorus and carbamate pesticides are acetylcholinesterase-inhibiting pesticides and as such have a common mode of action. We assessed the cumulative acute exposure of the population of Denmark to 25 organophosphorus and carbamate pesticide residues from the consumption of fruit, vegetables and cereals. The probabilistic approach was used in the assessments. Residue data obtained from the Danish monitoring programme carried out in the period 2004–2007, which included 6704 samples of fruit, vegetables and cereals, were used in the calculations. Food consumption data were obtained from the nationwide dietary survey conducted in 2000–2002. Contributions from 43 commodities were included in the calculations. We used the relative potency factor (RPF) approach to normalize the toxicity of the various organophosphorus and carbamate pesticides to the two index compounds chlorpyriphos and methamidophos. RPF values derived from the literature were used in the calculations. We calculated the cumulative acute exposure to 1.8% and 0.8% of the acute reference dose (ARfD) of 100 µg kg^–1 body weight (bw) day^–1 of chlorpyrifos as an index compound at the 99.9th percentile (P99.5) for children and adults, respectively. When we used methamidophos as the index compound, the cumulative acute intakes were calculated to 31.3% and 13.8% of the ARfD of 3 µg kg^–1 bw day^–1 at P99.9 for children and adults, respectively. With both index compounds, the greatest contributor to the cumulative acute exposure was apple. The results show that there is no cumulative acute risk for Danish consumers to acetylcholinesterase-inhibiting pesticides.     

Parental exposure to pesticides and poor clutch viability in American alligators

In central Florida, alligators (Alligator mississippiensis) inhabiting lakes contaminated with organochlorine pesticides (OCPs) produce eggs that have high OCP concentrations and low clutch viability (proportion of eggs in a clutch that yield a live hatchling) compared to those from less contaminated lakes (reference lakes). However, a clear dose-response relationship has not been established between OCPs and poor clutch viability. In order to better elucidate a cause and effect relationship between OCP exposure and clutch viability, we conducted concurrent field and laboratory studies. Our field study reaffirmed that eggs of wild alligators from OCP-contaminated lakes and wetlands continue to have lower clutch viability and higher OCP burdens than eggs from reference lakes. Our field study also demonstrated that OCP egg burdens were strongly correlated with clutch viability for some of the OCP-contaminated sites, but not all. To better test causal relationships, a parental exposure study was conducted using captive adult alligators. Our laboratory study demonstrated that dietary exposure of captive alligators to an ecologically relevant OCP mixture caused alligators to produce eggs with higher OCP burdens and reduced clutch viability, as compared to the captive-control population. The experimentally induced egg burdens and clutch viability reductions were similar to those of wild alligators from OCP-contaminated sites. Our field and laboratory results suggest parental OCP exposure may be contributing to low clutch viability in wild alligators inhabiting OCP-contaminated habitats, raising some concern for endangered crocodilians living in OCP-contaminated habitats.     

Modeling the probability of arsenic in groundwater in New England as a tool for exposure assessment

We developed a process-based model to predict the probability of arsenic exceeding 5 microg/L in drinking water wells in New England bedrock aquifers. The model is being used for exposure assessment in an epidemiologic study of bladder cancer. One important study hypothesis that may explain increased bladder cancer risk is elevated concentrations of inorganic arsenic in drinking water. In eastern New England, 20-30% of private wells exceed the arsenic drinking water standard of 10 micrograms per liter. Our predictive model significantly improves the understanding of factors associated with arsenic contamination in New England. Specific rock types, high arsenic concentrations in stream sediments, geochemical factors related to areas of Pleistocene marine inundation and proximity to intrusive granitic plutons, and hydrologic and landscape variables relating to groundwater residence time increase the probability of arsenic occurrence in groundwater. Previous studies suggest that arsenic in bedrock groundwater may be partly from past arsenical pesticide use. Variables representing historic agricultural inputs do not improve the model, indicating that this source does not significantly contribute to current arsenic concentrations. Due to the complexity of the fractured bedrock aquifers in the region, well depth and related variables also are not significant predictors.     

A preliminary assessment of consumer’s exposure to organochlorine pesticides in fruits and vegetables and the potential health risk in Accra Metropolis,Ghana

Accra Metropolis is the major recipient of agricultural produce in Ghana, with almost the entire population depending on rural agricultural activities for subsistence. To increase agricultural produce, various forms of pesticides are normally used in fruits and vegetable farming. The consequence is that several cases of pesticide poisoning have been observed. In this preliminary study, a field survey was carried out to assess the knowledge, attitudes, and peoples’ perception concerning the use of pesticides by farmers in fruit production. The residual concentrations of selected pesticides in pawpaw, imported apples and tomato samples and the potential health risks associated with the exposure to these pesticides were also assessed. The field survey data indicated that more than 70% of the participants reported one or more poisoning upon fruits consumption resulting in pesticide-related illnesses. Pesticide residues in the various environmental samples were determined by gas chromatography with electron capture detector (GC-ECD). The results showed that, the levels of pesticide residues varied from <0.01 μg/g to as high as 0.11 μg/g depending on the pesticide monitored. The analysis of health risk estimates revealed heptachlor, heptachlor epoxide, endrin aldehyde, and endrin ketone levels exceeded the reference dose, suggesting a great potential for systemic toxicity in children considered the most vulnerable population subgroup. Lastly, the public is in the know of pesticide residues in fruits and calls for the curtailing of pesticide use on fruits and vegetable production via educational programmes for farmers on control and safer use of pesticides.     

3-Chlorotyrosine formation in ready-to-eat vegetables due to hypochlorite treatment and its dietary exposure and risk assessment

Washing of iceberg lettuce with HOCl solutions in concentrations ranging from 1.41 to 141 mg/L resulted in 0.69 to 2.05 μg 3-chlorotyrosine/g vegetable. As also six commercial ready-to-eat iceberg lettuces from different producers contained 3-chlorotyrosine from 1.00 to 2.24 μg/g vegetable, a total of 122 ready-to-eat vegetable samples purchased in Belgian supermarkets were further screened for their 3-chlorotyrosine content. 3-chlorotyrosine was detected above the detection limit (0.19 μg/g sample) in 97, 24 and 14% of the lettuce mixes, vegetable mixes and frozen vegetables, respectively. In combination with consumption data of ready-to-eat vegetables by Belgian and Spanish consumers, a quantitative exposure assessment was performed, exemplifying a lower and higher ready-to-eat vegetables consuming population. Exposure to 3-chlorotyrosine from the frozen vegetables and vegetable mixes was lower compared to the lettuce mixes due to the combination of lower contamination and lower consumption. 3-chlorotyrosine exposure via lettuce mixes could be considered as a public health concern, especially in higher consuming populations represented by the Spanish population, with 17% of consumers (> 4.2 million people) and 8.5% of the total population (> 2,6 million people) exceeding the threshold of toxicological concern.     

Coupling multi-criteria decision analysis, life-cycle assessment, and risk assessment for emerging threats

Emerging environmental threats such as novel chemical compounds, biological agents, and nanomaterials present serious challenges to traditional models of risk analysis and regulatory risk management processes. Even a massive expansion of risk and life-cycle assessment research efforts is unlikely to keep pace with rapid technological change resulting in new and modified materials with changing properties. Therefore, it is essential to have a framework for interpreting available information in the context of high uncertainty and a strategy for prioritizing research efforts to reduce those uncertainties that are most critical. We discuss how integrating the three analytic approaches of risk assessment, life-cycle assessment, and multicriteria decision analysis into a framework permits understanding uncertainty and prioritizes needs for scientific research. Our approach is illustrated with two separate cases: nanomaterials and contaminated sediment remediation.     

Economic input-output life-cycle assessment of trade between Canada and the United States

With increasing trade liberalization, attempts at accounting for environmental impacts and energy use across the manufacturing supply chain are complicated by the predominance of internationally supplied resources and products. This is particularly true for Canada and the United States, the world's largest trading partners. We use an economic input-output life-cycle assessment (EIO-LCA) technique to estimate the economy-wide energy intensity and greenhouse gas (GHG) emissions intensity for 45 manufacturing and resource sectors in Canada and the United States. Overall, we find that U.S. manufacturing and resource industries are about 1.15 times as energy-intensive and 1.3 times as GHG-intensive as Canadian industries, with significant sector-specific discrepancies in energy and GHG intensity. This trend is mainly due to a greater direct reliance on fossil fuels for many U.S. industries, in addition to a highly fossil-fuel based electricity mix in the U.S. To account for these differences, we develop a 76 sector binational EIO-LCA model that implicitly considers trade in goods between Canada and the U.S. Our findings show that accounting for trade can significantly alter the results of life-cycle assessment studies, particularly for many Canadian manufacturing sectors, and the production/consumption of goods in one country often exerts significant energy- and GHG-influences on the other.     

A mixed-unit input-output model for environmental life-cycle assessment and material flow analysis

Materials flow analysis models have traditionally been used to track the production, use, and consumption of materials. Economic input-output modeling has been used for environmental systems analysis, with a primary benefit being the capability to estimate direct and indirect economic and environmental impacts across the entire supply chain of production in an economy. We combine these two types of models to create a mixed-unit input-output model that is able to bettertrack economic transactions and material flows throughout the economy associated with changes in production. A 13 by 13 economic input-output direct requirements matrix developed by the U.S. Bureau of Economic Analysis is augmented with material flow data derived from those published by the U.S. Geological Survey in the formulation of illustrative mixed-unit input-output models for lead and cadmium. The resulting model provides the capabilities of both material flow and input-output models, with detailed material tracking through entire supply chains in response to any monetary or material demand. Examples of these models are provided along with a discussion of uncertainty and extensions to these models.     

深圳市面粉与面制品中偶氮甲酰胺及其转化产物膳食暴露评估

目的了解深圳市居民面粉与面制品中偶氮甲酰胺及其分解转化产物联二脲、氨基脲的含量水平,获得深圳市致癌致畸物氨基脲的居民膳食暴露水平。方法 2016年在深圳市超市、批发市场、农贸市场等共采集500份面粉及面制品,监测偶氮甲酰胺及其分解转化产物联二脲、氨基脲的含量。并结合深圳市居民膳食调查食物消费量计算深圳市居民面粉和面制品中氨基脲的暴露量。结果所采集的500份样品中:偶氮甲酰胺、联二脲、氨基脲的检出率分别为4.60%、25.8%、18.6%,含量范围为0.500～93.4 mg/kg、10.0～13900μg/kg、0.250～1100μg/kg;氨基脲的一般水平暴露量与高水平暴露量分别为0.005μg/kg-bw/d与0.248μg/kg-bw/d。结论面粉及面制品中的氨基脲暴露已超过水产品中的暴露,应慎重使用偶氮甲酰胺作为食品添加剂在面粉及面制品中使用,同时加强对面粉及面制品中氨基脲的监测。     

Toxic epidemics caused by alimentary exposure to pesticides: a review.

Toxic epidemics have become a serious problem during the twentieth century, due mainly to the huge expansion over the last 50 years of the chemical industry, which has placed tens of thousands of new synthetic organic compounds in the human environment. In the particular case of chemical pesticides, their undiscriminating, widespread use, and harmful potential has been demonstrated by the epidemics generated by accidental contamination by pesticides of foods consumed by man, resulting in high mortality and morbidity rates. We have analysed the main characteristics of 63 outbreaks of toxicity caused by alimentary exposure to pesticides described in the scientific literature of this century, with the aim of increasing knowledge and understanding of the factors that are conducive to them or that trigger their onset. Such episodes are good indicators of the incorrect use of these products and serve to demonstrate failures of the available safety systems. We conclude by identifying some preventive measures that could be used to avoid their future repetition.     

Biological variability and exposure assessment

Predictive models are now commonly used for exposure assessment, with growth parameters defined for each microbial species. In this study, we tried to take into account microbial growth variability among strains of a single species. Bacillus cereus in pasteurized milk was chosen to illustrate the influence of the biological variability on the outcome of exposure assessment. Each parameter of the exposure assessment (growth parameters, shelf-life conditions) was characterized by a probability distribution describing variability and/or uncertainty. The impact of the intra-species variability on the result of the exposure assessment was then quantified and discussed. Two simple domestic shelf life conditions were tested. The results confirm that the biological variability has a great impact on the accuracy of the result and should not be systematically neglected.     

UK consumption databases relevant to acute exposure assessment

Consumption data can be expressed in different ways although it should be comparable to what is known about the toxicological property of the chemical in question and the likely pattern of consumer exposure. For example if the chemical has an acute toxic effect the consumption data should ideally be based on a single eating occasion or consumption over a single day and be based on the population of concern. This paper describes five UK dietary surveys and consumption data, specifically relevant to acute exposure assessment, from adult and pre-schoolchildren surveys. The acute consumption data are taken from the first day of the dietary regime. Closer examination of the dietary survey information suggests that either picking a random survey day or selecting all consuming days give 97.5 percentile values which are not significantly different. Consumption data are given for whole commodities and a few fruit juices. Examination of the dietary survey information shows that the consumption patterns are very different between whole commodities (e.g. apples), ingredients (e.g. apple in a dish or recipe) and juices and between adults and young children.     

New ecotoxicological model to simulate survival of aquatic invertebrates after exposure to fluctuating and sequential pulses of pesticides

Aquatic nontarget organisms are exposed to fluctuating concentrations or sequential pulses of contaminants, so we need to predict effects resulting from such patterns of exposure. We present a process-based model, the Threshold Damage Model (TDM), that links exposure with effects and demonstrate how to simulate the survival of the aquatic invertebrate Gammarus pulex. Based on survival experiments of up to 28 days duration with three patterns of repeated exposure pulses and fluctuating concentrations of two pesticides with contrasting modes of action (pentachlorophenol and chlorpyrifos) we evaluate the new model and compare it to two approaches based on time-weighted averages. Two models, the Threshold Damage Model and the time-weighted averages fitted to pulses, are able to simulate the observed survival (mean errors 15% or less, r2 between 0.77 and 0.96). The models are discussed with respect to their theoretical base, data needs, and potential for extrapolation to different scenarios. The Threshold Damage Model is particularly useful because its parameters can be used to calculate recovery times, toxicokinetics are separated from toxicodynamics, and parameter values reflect the mode of action.     

Risk assessment of dietary exposure to aluminium in the Chinese population

In order to address the issue of excessive intake of aluminium (Al) from Al-containing food additives in the Chinese diet, this study conducted a dietary exposure assessment of Al in the general population based on the national surveillance data of Al content in foods and national food consumption data. It was found that the mean dietary exposure of the whole Chinese population to Al from Al-containing food additives was 1.795 mg kg^?1 bw week^?1, not exceeding the PTWI, while high dietary exposures (e.g., 97.5^th percentile) to Al were 7.660 and 2.103–2.903 mg kg^?1 bw week^?1 for children, respectively, both exceeding the PTWI. It was found that the dietary exposure to Al for 32.5% of the total Chinese population and 42.6% of children aged 4–6 years exceeded the PTWI. Wheat flour and wheat-based products are the main source of dietary A l exposure (85% of the total intake); and puffed foods are the major source of Al intake for children. These findings suggested that consumption of Al-containing food additives could be a health concern for consumers with high food consumption (97.5^th percentile) and children under the age of 14 years.