Risk Assessment Of Pesticide Exposure Research Articles

A bispecific nanobody with high sensitivity/efficiency for simultaneous determination of carbaryl and its metabolite 1-naphthol in the soil and rice samples

The simultaneous determination of carbaryl and its metabolite 1-naphthol is essential for risk assessment of pesticide exposure in agricultural and environmental samples. Herein, several bispecific nanobodies (BsNbs) with different lengths of hydrophilic linkers and junction sites were prepared and characterized for the simultaneous recognition of carbaryl and its metabolite 1-naphthol. It was found that the affinity of BsNbs to the analytes could be regulated by controlling linker length and linking terminal. Additionally, molecular simulation revealed that linker lengths affected the conformation of BsNbs, leading to alteration in sensitivity. The BsNb with G4S linker, named G4S-C-N-VHH, showing good thermal stability and sensitivity was used to develop a bispecific indirect competitive enzyme-linked immunosorbent assay (Bic-ELISA). The assay demonstrated a limit of detection of 0.8 ng/mL for carbaryl and 0.4 ng/mL for 1-naphthol in buffer system. Good recoveries from soil and rice samples were obtained, ranging from 80.0% to 112.7% (carbaryl) and 76.5%–110.8% (1-naphthol), respectively. Taken together, this study firstly provided a BsNb with high sensitivity and efficiency against environmental pesticide and its metabolite, and firstly used molecular dynamics simulation to explore the influence of linker on recognition. The results are valuable for the application of immunoassay with high efficiency in the fields of environment and agriculture.

Damu-Safen pesticide exposure risk assessment, EC (fomesafen, 250 g/l)

Damu-Safen pesticide exposure risk assessment, EC (fomesafen, 250 g/l)

Health risk assessment of chlorpyrifos inhalation exposure among chilli-growing farmers in Na-Krasaeng Sub-District, Det Udom District, Ubon Ratchathani Province, Thailand

The paper reports a health risk assessment of pesticide exposure among chilli-growing farmers living in Na-Krasaeng Sub-District, Det Udom District, Ubon Ratchathani Province, Thailand. Personal air samples were collected from 46 participants spraying pesticide. These samples were analysed to investigate the farmers’ exposure by inhalation of the organophosphate, chlorpyrifos, which is the predominant pesticide used in the study area. The potential health risk of the farmers through inhalation was estimated by calculating the Hazard Quotient (HQ). The results showed that chlorpyrifos concentrations in inhaled air samples from the farmers ranged from less than the limit of detection, <LOD, to 0.041 mg/m3 with an average of 0.0072 mg/m3. Average daily doses (ADD) of exposure were calculated to be in the range 0–0.007 mg/kg/day with a mean value of 0.0014 mg/kg/day. The estimated risk quotient was 0 to 2.35 and the mean value was 0.84. Accordingly, the chilli-growing farmers were not considered to be a population at risk (mean value of HQ ≤ 1). But, the estimated risk of 17.38% of the study population was higher than the acceptable level (HQ > 1). This indicated that some participants were considered as an individual risk which should be of concern.

Acute Toxicity of Larval Honeybee to the Most Common Pesticides Detected in Pollen

Residual pesticide levels detected in pollen and honey in hive would be important factor in risk assessment of pesticide exposure for adult and larval honeybee. Herein, we investigated the cumulative mortality of larvae on single exposure of the four most common pesticides detected in pollen, and compared its susceptibility with the lethal dose 50% of adult bees. Four pesticides used in this study were acetamiprid, chlorothalonil, coumaphos, and tau-fluvalinate, which were mixed in artificial diet at the average and maximum residual concentrations reported in pollen. Chlorothalonil and tau-fluvailnate at the average levels induced higher cumulative mortality (respectively 25% and 17%) than other tested pesticides. Mortality occurred more quickly after single exposure in larvae treated with the maximum pesticide levels than the average levels. However, cumulative larval mortality did not increase pesticide-dose dependently in a single exposure test of four all pesticides. Based on the lethal dose 50% of pesticides for adult bees, the larval mortality was greater than bee adult mortality. Therefore, larval stage of honeybee might be much more sensitive to pesticides relative to the adult stage.

Assessment of risk of unfavourable effect of pesticides on operators (To the problem of harmonization of hygienic standards in Ukraine)

Introduction. The assessment of unfavorable effect of pesticides on operators is one of obligatory condition in making a decision on their state registration. A calculation of the exposure dose and definition of the permissible level, as main constituents in risk assessment, are made in ECC according to the unified algorithms. In order to introduce hygienic standards in Ukraine in accordance with European legislation, it is advisable to use the mentioned algorithms with due account of traditional national approaches to the conception on safety of pesticides and on work with them. Materials and methods. EEC Directives on sanitary legislation and methodical guidance on determination of exposed doses and permissible levels of pesticides for operators. Analysis of materials. Results. A deterministic predictive operative exposure model РОЕМ (EUROPOEM), using the database, covering worst-case scenario of the work with pesticides and the algorithm of operator exposure level (AOEL), the whole set of toxicological data, critical directions of nonoperative exposure levels (NOAEL) with the safety coefficient, providing the extrapolation of experimental data on man (operator), can be used as algorithms, presenting uniqueness and transparency of conclusions on risk assessment of pesticide exposure on operators’ health. These algorithms can be recommended for risk assessment in pesticide application by operators in Ukraine. Conclusion. 1. When making a decision by the results of the quantitative level of exposure from the point of view of the predictive value of a model, a preference should be given to the algorithm, based on the most full «historical» databases, including cases not foreseen by worst cases. UK POEM and its modified variant EUROPOEM II, which are proposed for adoption in Ukraine, as an official algorithm for calculation of the exposure doses of pesticides in their application, seems to be the most acceptable. 2. It seems appropriate to substantiate allowable levels of pesticides in their effects on operators in Ukraine by the algorithm EFSA, with due account of individual judgments on the degree of safety, based on the analysis of all set of available toxicological data and approve them in due order as a state hygienic standard.

Farmers’ exposure to herbicides in North Italy: Assessment under real-life conditions in small-size rice and corn farms

Although rice and corn are two main cash crops in Lombardy (North Italy) and their cultivation involves several thousands of farmers, risk assessment of pesticide exposure is rarely done, especially in small and medium sized enterprises. With the use of pads for environmental monitoring (OECD protocol), of pre- and post-exposure 24h urine collection for biological monitoring and of hand wash for hands’ exposure, we measured the exposure of 28 agricultural workers to propanil and terbuthylazine in real-life working conditions. In propanil applicators, median daily exposure on the clothes was 73.5μmol per worker, while the exposure on the skin was 22.4μmol. For terbuthylazine, these exposures were 37.2μmol and 0.86μmol per worker, respectively. Median excretion of the propanil metabolite (3,4-dichloroaniline) after exposure was 84nmol in 24h urine, and 13nmol for the metabolite of terbuthylazine. Risk assessment performed by comparing to the AOELs of the applied active ingredients with an estimated internal dose, obtained based on the measured levels of skin and hand exposure and the percentage of dermal absorption of the active ingredients considered showed that 4 propanil workers, and no terbuthylazine workers, were overexposed. Our study helps define and confirm relationships between different exposure determinants, which can be used in the development of tools for risk assessment of exposure to pesticides in small and medium sized enterprises.

Use of biochemical biomarkers in the ecological risk assessment of permetrin pesticide exposure

Biochemical biomarkers were used in ecological risk assessment of pesticide exposure. The experiments were carried out on six weeks old poultry birds (Gallus domesticus) weighing between 400 and 600 g (12 birds) and were divided into four groups of three birds each. The poultry birds were exposed for four weeks to different concentrations (1, 5 and 10%) of a locally manufactured insect powder called ‘Rambo’ which contains 0.6% permethrin. The control group had no pesticide added to their feed. Results of the experiment showed a significant increase (p 0.05) in the levels of total and conjugate bilirubin and creatinine between the treatments and the control, while urea showed significant difference at 5 (22.38 ± 0.42 mg/dl) and 10% (25.39 ± 0.50 mg/dl) pesticide contamination, respectively. Lipid peroxidation and lactate dehydrogenase showed significant differences at all levels of pesticide contamination, indicating possible oxidative stress. As such, results of this experiment support the use of biochemical biomarkers in the ecological risk assessment of pesticide contaminated environment. Key words: Biochemical biomarkers, ecological risk assessment, pesticide contamination, non-target animals, poultry birds.

Erratum: Risk assessment of pesticide exposure on health of Pakistani tobacco farmers

Erratum: Risk assessment of pesticide exposure on health of Pakistani tobacco farmers

Risk assessment of pesticide exposure on health of Pakistani tobacco farmers

Tobacco is an important cash crop of Pakistan. Pesticides are commonly used to increase the crop yield, but their health impact has not been studied yet. The objectives of the study were to determine the frequency of pesticide poisoning and to explore the knowledge, attitudes and practices (KAP) towards safety measures among the tobacco farmers in Swabi, Pakistan. One hundred and five tobacco farmers involved in pesticide application were randomly selected from two villages of district Swabi. A structured questionnaire was used for clinical and KAP information. Plasma cholinesterase (PChE) levels were measured by Ellman's method by using GD Italy kits. All tobacco farmers were males with a mean (SD) age of 26 (9) years. The majority of the farmers reported multiple symptoms headache, dizziness, vomiting, shortness of breath, muscle weakness and skin rash correlate with the clinically significant depression of PChE levels. Out of 105 pesticide applicators, 58 (55%) had post-exposure reduction in PChE levels <20% from baseline, 35 (33%) had mild poisoning (20-40% reduction) and 12 (11%) had moderate poisoning (>40% reduction). Most of the farmers did not use any personal protective equipment during pesticide handling. Only a few used shoes (31%), masks (14%) and gloves (9%) during pesticide spray. In conclusion, the tobacco farmers had mild to moderate pesticide poisoning, which was correlated with depression in PChE levels. Moreover, most farmers had little knowledge about the safety measures, casual attitude and unsatisfactory safety practices with regard to the use of basic protective equipments during pesticide applications on the tobacco crop.

Exposure of bystanders to pesticides

Graham A. Matthews from IPARC, Imperial College, Silwood Park and Paul Y. Hamey from PSD, DEFRA, York, both in the UK, describe recent risk assessment of pesticide exposure to so-called bystanders.