Changes in pest management practice in almond orchards during the rainy season in California , USA
In California, regulatory agencies are concerned about organophosphate (OP) contamination of surface water. OPs originate in part from applications on dormant almond and stone fruit orchards that are washed off during winter rainstorms. Programs conducted by the University of California Statewide Integrated Pest Management Project, University of California Cooperative Extension, and the Biologically Integrated Orchard Systems (BIOS), a coalition of public and private groups, have promoted the replacement of OPs on almonds during the rainy season with alternative practices. Data from individual applicator records from the California Pesticide Use Reports demonstrated that during 1992–1997, almond growers in all nine major almond-producing counties significantly reduced use of OPs. The area of almond orchards treated with OPs during the dormant season was reduced by 40–55%, depending upon the region. Similarly, the percentage of growers who used OPs during the dormant season was reduced by 31–48%, and the mass of OPs applied to almond orchards during the dormant season was reduced by 22–57%. During the same period, there was a significant increase in the percentage of growers who used “reduced-risk” treatments: the microbial pesticide Bacillus thuringiensisat bloom-time, oil without an insecticide during the dormant season, and no treatment during the dormant or bloom season. In addition to the decrease in OPs during the dormant season, there was a significant decrease in the area treated with OPs during the growing season. However, there was also a significant increase in the use of pyrethroids during the dormant season, a practice that might result in some surface water and sediment contamination. © 2001 Elsevier Science B.V. All rights reserved.
Occupational Pesticide Exposures and Respiratory Health
Pesticides have been widely used to control pest and pest-related diseases in agriculture, fishery, forestry and the food industry. In this review, we identify a number of respiratory symptoms and diseases that have been associated with occupational pesticide exposures. Impaired lung function has also been observed among people occupationally exposed to pesticides. There was strong evidence for an association between occupational pesticide exposure and asthma, especially in agricultural occupations. In addition, we found suggestive evidence for a link between occupational pesticide exposure and chronic bronchitis or COPD. There was inconclusive evidence for the association between occupational pesticide exposure and lung cancer. Better control of pesticide uses and enforcement of safety behaviors, such as using personal protection equipment (PPE) in the workplace, are critical for reducing the risk of developing pesticide-related symptoms and diseases. Educational training programs focusing on basic safety precautions and proper uses of personal protection equipment (PPE) are possible interventions that could be used to control the respiratory diseases associated with pesticide exposure in occupational setting.
A four‐day survival and reproduction toxicity test for ceriodaphnia dubia
A 4-d survival and reproduction toxicity test utilizing Ceriodaphnia dubia has been developed and evaluated. This toxicity test has been compared to the standard 7-d test using a total of 12 toxicants encompassing a wide range of chemical classes. In addition, 48-h LC50 values were determined for each chemical in the absence of food. Four-day and seven-day tests were run concurrently, twice for each chemical. Less-than-12-h-old neonates for both 4-d and 7-d tests were segregated into individual test cups on Fridays. Animals for 7-d tests were immediately exposed to the test chemical. Animals for 4-d tests were held in control water and not exposed to the test chemical until day 3. Animals were fed daily and solutions were changed on Mondays and Wednesdays. Chemical concentrations were measured by appropriate analytical techniques during each test. Survival and mean total young per female were used to compare the relative sensitivity of the 4-d and 7-d tests. Data were analyzed using traditional hypothesis testing techniques to determine chronic values from the no-observed- and lowest-observed-effect concentrations. In addition, data were analyzed using a nonparametric, monotonic smoothing technique to determine interpolated point estimates and 95% confidence intervals for the 50% inhibition concentration (IC50). Comparisons between the 4-d test versus the 7-d test for both methods of data analysis indicated that the 4-d test provides an acceptable level of sensitivity in the toxicity testing of single compounds.