Pesticide residues in Italian Ready-Meals and dietary intake estimation

The investigations carried out during 2005 by state-run Italian laboratories within the framework of controls seeking pesticide residues monitoring in foodstuffs involve quantifying the levels of such residues in fruit and vegetable produce and their processed products: oil, wine and fruit juices. The Italian Ready-Meal Residue Project, promoted by the pesticides working group of Italian Environmental Agencies, seeks to asses the quantity of pesticides in pre-prepared (ready-to-eat) lunches (comprising a first course, side dish, fruit, bread and wine), and to quantify the amounts consumed and compare with the acceptable daily intake ADIs.The data provided by 16 laboratories which analyzed 50 complete meals in 2005 (samples taken on 8 February, 26 May, 24 October, 21 December 2005) showed residues in 39 lunches, with an average number of 2.4 pesticides in each meal and a maximum of 10 pesticides. The most frequently found substances were: pirimiphos-methyl (20 times), procymidone (17), pyrimethanil (7), iprodione (7), cyprodinil (7), fenitrothion (6), diphenylamine (6), chlorpyrifos (6), metalaxyl (5) and chlorpyrifos-methyl (5).The distribution of residues among each dish of the meal was also examined, and the results showed that: 77.3% of the residues were present in the fruit, 14.9% in the wine, 3.0% in the main course, 2.8% in the bread and 2.1% in the side dish. Assuming that two meals are consumed per day, the daily intake of pesticide residues was calculated on a daily basis, in relation to normal body weight (60 kg for an adult, 40 kg for a teenager, 20 kg for a child) and compared with the ADI values established by the European Union. In the case of adults, the average daily intake of pesticides in relation to ADI was 2.6% with a maximum of 73.3%; for teenagers it was 4.9% with a maximum of 109% and for children it was 9.8% with a peak of 219%.     

Can time-weighted average concentrations be used to assess the risks of metsulfuron-methyl to Myriophyllum spicatum under different time-variable exposure regimes?

We tested the effects of the herbicide metsulfuron-methyl on growth of the submerged macrophyte Myriophyllum spicatum under laboratory conditions using different exposure scenarios. The exposures of each scenario were comparable in the concentration × time factor, viz., the same 21-d time-weighted average (TWA) concentrations but variable in peak exposure concentrations (ranging from 0.1 to 21 000 ng ai L⁻¹) and exposure periods (1, 3, 7, 14 or 21 d). To study recovery potential of the exposed M. spicatum plants we continued the observation on shoot and root growth for another 21 d in herbicide-free medium so that the total observation period was 42 d. Non-destructive endpoints, length and number of new shoots and roots, were determined weekly from day 14 onwards. Destructive endpoints, dry-weight (DW) of main shoots, new shoots and new roots, were measured at the end of the experiment (t = 42 d).Metsulfuron-methyl exposure in particular inhibited new tissue formation but was not lethal to main shoots. On days 21 and 42 after start exposure, EC₁₀/EC₅₀ values for new tissues expressed in terms of peak concentration (=measured concentration during exposure periods of different length) showed large differences between exposure scenarios in contrast to EC₁₀/EC₅₀ values for days 21 and 42 expressed in terms of 21-d and 42-d TWA concentrations, respectively. At the end of the experiment (day 42), 42-d TWA EC_x values were remarkably similar between exposure scenarios, while a similar trend could already be observed on day 21 for 21-d TWA EC_x values. For the macrophyte M. spicatum and exposure to the herbicide metsulfuron-methyl the TWA approach seems to be appropriate to use in the risk assessment. However, the data from the toxicity experiment suggest that on day 21 also the absolute height of the pulse exposure played a (minor) role in the exposure - response relationships observed.     

Improvement of Vicia-micronucleus test for assessment of soil quality: a proposal for international standardization

The Viciafaba root tip micronucleus test is one of the most employed plant genotoxicity assays, and has been used on various types of contaminated materials. This test has been standardized by AFNOR, the French member organization of ISO. However, this test is usually performed with a water extraction step but soil genotoxicity assessment would be more relevant when performed directly in the soil itself. In order to harmonize these protocols, an ISO standard for the V.faba micronucleus test in both liquid phase (exposure of plants to different liquid matrix, including soil water extracts) and solid phase (direct exposure of plants to the soil) would be very useful. In this context, we compared two exposure durations in the solid phase (48 h and 5 d) for the V.faba micronucleus test with two different well-known genotoxicants, maleic hydrazide and copper sulfate. We concluded that these two durations induced equivalent sensitivity: the micronucleus frequency was significantly increased with 5 μmol maleic hydrazide per kg dry soil and with 2 mmol copper sulfate per kg dry soil with both exposure durations. However, exposing roots to soil during 48 h is more practical. Moreover, organically and conventionally cultured seeds were employed to determine whether the seed provenance influenced the test sensitivity. Organic seeds were less sensitive to copper, possibly because copper-based treatments are permitted, and often applied, in organic farms. Therefore, in the absence of completely non-treated seeds, organically-cultured seeds did not appear to offer any advantages over conventional seeds.     

Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults

Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations.     

Health implication among occupational exposed workers in a chromium alloy factory, Thailand

IntroductionNationalStatisticalOffice ,Thailand (NSO ,2 0 0 0 )reportedthattheneedformetalmanufacturingindustriesandassociatedproductionsectorhasincreasedatanextremelyrapidrate ,especiallyinthecentralpartofThailand .Itisestimatedthattherearemorethan 10 0 …     

Benzene and lead exposure assessment among occupational bus drivers in Bangkok traffic

IntroductionAirpollutionproblemsasaresultoffastgrowthinthetotalnumberofvehiclesinurbancitiesareontheincrease .PreliminaryepidemiologicalexposureassessmentsuggestthatthedetrimentaleffectofairpollutiongeneratedbyvehiculartrafficindevelopingcitieslikeBangkok…     

不同冷却方式下高温后圆钢管再生混凝土界面黏结性能对比分析

为研究自然冷却(自冷)和喷水冷却(水冷)两种方式对高温后圆钢管再生混凝土界面黏结性能的影响差异,以冷却方式、历经最高温度(T)和再生粗骨料取代率(r)为变化参数,设计并完成了21个试件的静力推出试验,观察了试件的破坏过程及形态,获得了荷载-滑移曲线,对比分析了不同冷却方式对高温后圆钢管再生混凝土短柱物理特征、界面破坏过程及黏结性能指标的影响。结果表明：与自冷试件相比,水冷试件的质量烧失率明显减小、初始滑移发生更晚,且在荷载-滑移曲线下降段中,水冷试件表现得更平缓。在自冷方式下,随着历经最高温度的增大,试件的界面黏结强度先减小后增大,但在水冷方式下,界面黏结强度先增大后减小;与自冷试件相比,T超过400℃后水冷试件的界面黏结刚度开始退化,在600℃时界面黏结刚度退化较大;无论是自冷还是水冷,随着历经最高温度的增大,界面黏结耗能系数不断减小。     

广州人群尿液有机磷阻燃剂的暴露与健康风险

针对广州480名普通群众,利用尿液作为检测基质,研究人体内有机磷酸酯阻燃剂(OPFRs)代谢物的浓度水平,暴露的潜在来源,阐明其健康风险,并与其他包括邻苯二甲酸酯在内的多种有机污染物的健康风险对比筛选出高风险污染物.结果表明,广州居民体内普遍检出OPFRs代谢物,其平均浓度为6.59ng/mL,尤其是二-β,β-氯乙基...     

镉对孕鼠胎盘激素合成功能的毒性效应

为探究孕期低剂量镉暴露对胎盘激素合成功能的毒性效应,选择雌三醇和孕酮激素作为研究对象,基于研究的孕期低剂量镉暴露小鼠模型,通过生物化学方法检测镉暴露小鼠的血液和胎盘中的雌三醇和孕酮激素含量及其合成底物浓度,并通过实时定量PCR法对胎盘中相关激素合成基因的表达水平进行检测.结果表明,孕期低剂量镉暴露可导致小鼠血清和胎盘中...     

基于DFR的2024-T3铝合金当量加速关系试验研究

目的 提出以反映结构材料疲劳性能的DFR为表征参量,研究建立2024-T3铝合金结构在大气自然环境预腐蚀与实验室加速试验预腐蚀后的DFR关系,为腐蚀环境下飞机铝合金结构的疲劳寿命设计提供方法。方法 以2024-T3铝合金试验件为研究对象,分别开展典型海洋大气环境自然暴露腐蚀后的DFR试验以及实验室加速腐蚀试验后的DFR试验,以DFR相等为条件,建立上述2种不同预腐蚀条件之间的DFR当量加速关系。结果 2024-T3铝合金在自然暴露预腐蚀环境与实验室加速预腐蚀后的DFR值随腐蚀时间的增加均有不同程度的下降,万宁和青岛的DFR当量加速值分别为0.642 1、0.701 2 a/d。结论 基于DFR的当量加速关系综合反映了预腐蚀对结构材料疲劳性能退化的影响,而DFR是飞机结构疲劳设计的基本参量,文中建立的当量加速关系可用于指导腐蚀环境下铝合金的疲劳寿命设计分析。