High-risk Pesticides Research Articles

Uso de plaguicidas inhibidores de acetilcolinesterasa en once entidades territoriales de salud en Colombia, 2002-2005

Due to the importance of acetylcholinesterase inhibiting chemicals as pesticides in developing countries, the Instituto Nacional de Salud in Colombia designed the organophosphate and carbamate epidemiological surveillance program for the period 2002-2005. The acetylcholinesterase activity was determined in study participants with a history of organophosphate and carbamate exposure and the most commonly used pesticides were identified in each study area. The information was compiled from reports sent to the Instituto Nacional de Salud organophosphate and carbamate epidemiological surveillance program from each of 11 provinces in Colombia. The analytical determination of the biomarker was performed by acetylcholinestare activity determined with the Lovibond field equipment. A total of 28,303 people were designated as having risk of exposure to pesticides. Most were men (81.4%). Abnormal determinations averaged 9.3% (9.9% in men and 7.0% in women). The 18-25 year old age group showed the highest prevalence of abnormal results (12.3%), followed by the group of 0-5 year olds (10.7%). The highest prevalence of abnormal acetylcholinesterase activity was in farm workers (27.0%), followed by general outdoor activities (26.1%). In the province of Meta, 80% of participants showed abnormal values of enzyme activity. The most commonly used pesticides were organophosphates (39.7%) and carbamates (16.6%). The increase in the prevalence of abnormal values of acetylcholinesterase activity and the risk of exposure to pesticides in children necessitates a lowering of use and commercialization of high risk pesticides, and a need for developing safer methods for pest management.

High risk pesticides in sugar beet protection

According to traits of pesticides permitted to use in sugar beet (oral percutaneus and inhalation toxicity, toxicity to wildlife, bees and aquatic organisms, re-entry interval, maximum number of treatments, effects on reproduction) do not present health risk in sugar production/technology. However, the danger exists for workers by chronic exposure during the application, especially from pesticide being potential endocrine disruptors (EDS) (fentin acetate, benomyl, endosulfan, methomyl, methidathion). EDS can cause sterility or decreased fertility, impaired development, birth defects of the reproductive tract and metabolic disorders. Authors recommend limited application of EDS pesticides (to limit the number of treatments to only one during the vegetation), replacement with pesticides with low risk to humans game and fishes, as well as mandatory submission of re-entry data for registration.

Developing a pesticide risk assessment tool to monitor progress in reducing reliance on high-risk pesticides

A methodology is presented for the development of a pesticide risk assessment tool that was used to monitor progress in reducing use of high-risk pesticides in Wisconsin potato production. Multi-attribute toxicity factors are calculated that reflect each pesticide’s acute and chronic toxicity to mammals, birds, fish and small aquatic organisms, and compatibility with biointensive Integrated Pest Management. These factors are then multiplied by the pounds of active ingredient of a given pesticide applied to estimate pesticide-specific toxicity units. Wisconsin potato industry baseline toxicity units by type of pesticide and for 11 targeted higher-risk pesticides are presented for 1995. Reductions in toxicity units from this baseline are reported for 1997 and 1999, as are reductions achieved in a commercial-scale field experiment in 2000.

Effects of Soil Variability and Weather Conditions on Pesticide Leaching— A Farm‐Level Evaluation

In line with European regulations, Dutch law imposes an environmental threshold of 0.1 microg L(-1) on pesticide concentrations in ground water. During registration, the risk of exceeding this threshold is assessed through simulations for one or a few standard scenarios that do not reflect spatial variability under field conditions. The introduction of precision agriculture, where soil variability is actively managed, can increase control over pesticide leaching. This study presents a step-wise evaluation of the effects of soil variability and weather conditions on pesticide leaching. The evaluation was conducted on a 100-ha arable farm and aimed at identifying opportunities for precision management. As a first step, a relative risk assessment identified pesticides presenting a relatively high risk to the environment. Second, the effect of weather conditions was analyzed through 20 years of simulations for three distinct soil profiles. Results were summarized in cumulative probability plots to provide a probabilistic characterization of historical weather data. The year matching 90% probability (1981) served as a reference to simulate pesticide leaching from 612 soil profiles. After interpolation, areas where concentrations exceeded the environmental threshold were identified. Out of a total of 19 pesticides, isoproturon [N-dimethyl-N'-(4-(1-methylethyl)phenyl)urea], metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], and bentazon [2,1,3-benzothiadiazin-4(3H)-one, 3-isopropyl-, 2,2-dioxide] showed the highest risk for leaching. Leaching was strongly affected by soil variability at the within-field, field, and farm levels. Opportunities for precision management were apparent, but depended on the scale level at which environmental thresholds were implemented. When legislation is formulated in this issue, the presented step-wise evaluation can serve as a basis for identification and precision management of high-risk pesticides.

A Risk-based Approach for Selecting Priority Pesticides for Groundwater Monitoring Programs

A technique for screening pesticides with respect to their overall risk to potential contamination of groundwater was developed for the purpose of selecting priority pesticides for groundwater monitoring programs. The risk assessment technique considers leaching potential, extent of usage, and toxicity of pesticides. These three factors were integrated to obtain an index, the Impact Potential Score (IPS). To evaluate leaching potential, a second index, Total Mobility Index (TMI) was also developed. The two indices were evaluated for their performance by applying them to a monitored watershed in Virginias Coastal Plain. TMI predictions were compared against five years of groundwater monitoring data. TMI performed fairly well in identifying the top few high mobility pesticides. The IPS can be effectively used to select high risk pesticides for groundwater monitoring programs and for qualitative risk assessment. Incorporation of risk screening techniques into environmental management decision processes is useful for evaluation of pesticide contamination potential of groundwater.