Estimated nationwide effects of pesticide spray drift on terrestrial habitats in the Netherlands

This study estimated the potential effects of pesticide drift on terrestrial ecosystems outside target areas, for the Dutch situation. A series of field trials was conducted to estimate the effects of drift on different species groups at different distances from a treated plot for different categories of pesticide: herbicides, fungicides and insecticides. Measurements of the pesticide drift deposition resulting from standard agricultural practice were used to model deposition outside the treated area. These data were then combined with national statistics on cropland and pesticide use to assess the ecological effects of pesticide drift for the Netherlands as a whole. Three scenarios were considered: the recent past (1998), the present (2005) and an optimised scenario based on 'best available practice' (2010). In the recent past the impact of herbicide drift on sensitive life stages non-target vascular plants is estimated to have exceeded the 50% effect level on 59% of adjacent linear landscape elements such as ditch banks and hedgerows. For the impact of insecticides and fungicides on non-target insects and fungi this 50% effect figure was 29% and 28% of linear elements, respectively. In the present situation, with (narrow) unsprayed buffer zones and other measures in place, these percentages are down to 41% for herbicides, 21% for insecticides and 14% for fungicides. In the optimised scenario, with a greater buffer width of 2.25m for potatoes (compared to 1.50m in 2005) and 1m for other crops (compared to 0.25 and 0.5m in 2005) and 'best available practice', these percentages can be cut to zero. In natural areas located within farming regions the 10% effect level can be reduced from 31% of such areas (1998) to 0% under conditions of 'best available practice'.     

High performance liquid chromatographic determination of pesticides in soluble phase and suspended phase in river water

A high performance liquid chromatographic method has been developed to determine pesticides in river water as both dissolved phase and suspended phase. The target pesticides were eight herbicides, asulam, diuron, flazasulfuron, linuron, MCPB, mecoprop, pyrazosulfuron‐ethyl and siduron, and two fungicides, oxine‐copper and thiram. The pesticides in filtered river water were extracted with styrene‐divinylbenzene copolymer and were eluted with acetonitrile. The pesticides on suspended solids were extracted ultrasonically with acetonitrile. Each eluate was concentrated and analyzed by HPLC with multiwavelength detector. Recoveries of the pesticides in the overall procedure of this method were 78–114% for filtered river water and 75–107% for suspended solids. The limits of detection in water and suspended solids ranged from 0.1 to 0.9 μg/L and 1 to 7 μg/g, respectively. Pesticide distribution between soluble phase and suspended phase in river water was measured by this method.     

Potential of rice husk ash in atrazine removal

An experimental study was carried out to explore the possibility of using a prepared microporous material, Rice Husk Ash (RHA) as an alternative to the commercial Powdered Activated Carbon (PAC), to remove atrazine (ATZ) pesticide from aqueous solution. The effects of contact time and pH on the adsorption were studied using the batch technique. Based on Hückel model calculations, the zwitterion behaviour of atrazine molecule was proved to be related to the pH of zero charge point of adsorbents (6.8 for RHA and 8.2 for PAC). The results showed that the Pseudo Second Order model is applicable to both adsorbents, suggesting that chemisorption is the rate-limiting step. The equilibrium data fitted well with the Langmuir model in the case of RHA, whereas the Freundlich model better fitted the equilibrium data in the PAC case, suggesting the existence of multi-layer adsorption of atrazine. The adsorption for RHA was found to be feasible and spontaneous, with a removal capacity of atrazine of more than 7?mg?g^?1. With regard to the BET surface, this removal capacity (50.5?µg_ATZ / m²_RHA) was 25% better than that PAC (37.75µg_ATZ / m²_PAC).     

Permethrin induced oxidative stress and neurotoxicity on the freshwater beetle Laccophilus minutus

Biomonitoring has become a useful tool in environmental risk assessment of anthropogenic activities releasing disturbing pollutants. Permethrin, used worldwide to control a wide range of pest insects, can threaten aquatic biota, potentially useful as precocious bioindicators in ecotoxicology. This study seeks to assess the acute toxicity permethrin to the freshwater beetle, its availability in water, as well as, its uptake. The acute toxicity of permethrin to non-target species was studied under laboratory conditions to assess its effect, after the exposure 48 h, on the freshwater beetle Laccophilus minitus considering changes in some enzymatic activities; a specific biomarker of neurotoxicity (acetylcholinesterase) and a non-specific biomarker of oxidative stress (superoxide dismutase and catalase). The rates of permethrin in water and insects were determined using gas chromatography. The low measured concentration of the pesticide 0.0013 μg/L didńt modify the SOD and CAT activities in comparison with controls, only the high concentrations (0.023 and 0.18 μg/L) induced a significant increase in the enzyme activity. A similar profile was recorded for the H₂O₂ level. The permethrin treatment induced a drastic depletion of AChE activity. As outcomes, uptake at a low level (<6.8 ± 0.43 ng/g dry weight) showed to be the factor underlying the alterations in the beetles exposed to permethrin. Such findings provide information on the behaviour of permethrin within the environment and its biological target through its neurotoxicity and induction of oxidative stress in a freshwater beetle.     

Occurrence and ecotoxicological risk assessment of pesticides in sediments of the Rosetta branch, Nile River, Egypt

This study aimed to (1) monitor the occurrence and spatiotemporal variations of 100 pesticides in sediments collected monthly from July 2018 to June 2019 from sampling sites in El-Rahawy, Sabal, and Tala, along the Rosetta branch of the Nile River, Egypt, and (2) perform an ecological risk assessment for aquatic organisms upon exposure to the detected sediment pesticides based on the risk quotient (RQ) method. Out of the 100 pesticides monitored, 16 pesticides belonging to seven chemical families were detected, and 55% of the sediment samples were contaminated with one or more pesticide residues. The mean concentration (mg/kg dry weight (dw)) and detection frequency (%) of the four most frequently detected pesticides in the sediment samples were as follows: chlorpyrifos (0.18 mg/kg dw and 34%), p,p′-DDE (0.018 mg/kg dw and 30%), cypermethrin (0.03 mg/kg dw and 14%), and deltamethrin (0.026 mg/kg dw and 13%). The spatial distribution exhibited that El-Rahawy had the highest pesticide load (2.86 mg/kg dw) among the studied sites, whereas the temporal variations revealed that the highest total pesticide concentrations were detected in winter season (1.73 mg/kg dw). Meanwhile, 12 pesticides showed high RQs (>1), posing a potential ecological risk to aquatic species that live and feed on such sediments.     

Use of micellar liquid chromatography for rapid monitoring of fungicides post harvest applied to citrus wastewater

A method based on micellar liquid chromatography has been developed to simultaneously monitor four pesticides largely post-harvest applied to citrus:thiabendazole,pyrimethanil,o-phenylphenol and imazalil.Water samples were filtered and directly injected without other treatment,thus avoiding extraction steps.The composition of the mobile phase was optimized using a chemometrical approach to achieve and excellent resolution to 0.07 mol/L SDS/5%,V/V 1-pentanol buffered at p H 3.Mobile phase run through a C18 column at 1 m L/min at room temperature.The detection was performing by UV–Visible absorbance using a wavelength program:0–10 min,305 nm(for thiabendazole);10–12;265 nm(for pyrimethanil)and 12–18,220 nm(o-phenylphenol and imazalil).The developed method was validated following the guidelines of the US Environmental Protection Agency in terms of:quantitation range,(0.5–4 to 15μg/m L),linearity(r20.9995),sensitivity(LOD,0.18–1.4μg/m L),precision(9.2%),trueness(93.9%–103.7%),and ruggedness(9.9%).It was found that the fungicides remain up to eight days in surface water at outdoor conditions.The method was used to screen the presence of the analytes in several waste water samples,and was proved to be useful in routine analysis.     

农用化学物资对土壤的污染状况与控制措施

随着现代化学农业的兴起与发展,不可避免地给环境造成污染。结合目前研究进展,主要从化肥、农药、地膜三方面入手,论述现代农业生产实践中,农用化学物资对重要的自然资源—土壤的污染状况及控制措施     

某废弃农药生产场地地下水挥发性有机物污染健康风险评价

对常州某废弃农药生产场地地下水中挥发性有机物污染状况和健康风险进行了调查评价。结果表明，该场地地下水中挥发性有机物污染以苯系物、氯代苯类和氯代烃类为主；部分点位地下水健康风险评价结果超出可接受范围，可能危害人体。     

环境样品中农药的前处理及检测技术研究进展

综述了近年来农药环境样品的前处理及检测技术,介绍了各种前处理和检测技术的应用情况,在此基础上对环境中残留农药的前处理及检测技术的发展进行了展望.