Agricultural farming practices, forestry or horticultural involve the use of many pesticides to deal with problems created by the proliferation of weeds, fungal diseases and insect pests. It is well known that users can be exposed to these pesticides during the preparation or implementation and means of prevention must be put in place to ensure their safety. However, other categories of workers may be exposed when performing certain manual tasks on a soil treated with pesticides. Workers who carry out monitoring activities in culture, manual weeding and harvesting may be exposed significantly during skin contact with soil and / or vegetation previously treated. For example, a recent study by the Center for Toxicology of Quebec (CTQ) in an industry growing roses has allowed us to measure significant decreases cholinesterases in workers engaged in collecting flowers (Samuel and Lefebvre, 1994).
[...] To fill the void in this area, CTQ, at the request of the Ministry of Natural Resources Quebec, conducted a study to propose and validate criteria for determining re-entry delays for pesticides used in forest nurseries (Samuel et al., 1996). This article is a summary of this study. Criteria for Determining Times Reentrancy Provision In the case of pesticides for which no specific period of re-entry has been determined during the certification process, several approaches have been proposed since the early 70s. [...]
[...] moderate Source: Table adapted (Hayes and Laws, 1991) Although the study is the work in forest nurseries, we believe that such an approach could also be used for agriculture and horticulture. A validation phase should be carried out for these activities given the differences observable on the framework. We believe, among other things, the hours worked during the day and the types of vegetation. References Bergerová VF, Pierce JT, Oraz PO (1990) Dermal absorption of industrial chemicals: criteria for skin notation, Am J Ind Med 17:617-35. [...]
[...] moderately toxic 72 h when the product has a (500% Oral LD50 mg / kg, or significant potential for dermal toxicity in humans (depending on LD mg / kg) model) Mixture of two pesticides moderately Are delays in re-entry of these or very toxic pesticides More time proposed by the Meet this deadline manufacturer Greenhouses and tunnels Additional period of 24 h if good ventilation is impossible * Moderate or severe irritation and / or skin damage which persisted over 72 h in animal studies Evidence of carcinogenicity in animals or possible carcinogen in humans and / or persistent physiological alterations in humans (eg neuropathy) According to the approach Bergerová et al. [...]
[...] Estimating the total exposure of workers by measuring the parent product and / or metabolites in the urine for a period of 24 hours and check the correlation between the urinary and dermal exposure. After consultation with nurseries, choice of pesticides was arrested on the following active substances: simazine and fluazifopbutyl (herbicides), benomyl (fungicide) and chlorpyrifos (insecticide). Methodology In order to identify the risks of worker exposure, we evaluated the residues in soil and surface residue levels dislodgeable plants during a period of sometimes up to 96 h. [...]
[...] The new criteria proposed in the second year of the project and finally selected as a tool for determining possible temporary re-entry are presented in the conclusion. Results For three of the products, the results showed that residues dislodgeable plants generally decreased significantly between the period of 1 hour and 24 hours after application. In the case of benomyl, lower residue dislodgeable was significant only after a period of rain. Furthermore, it was impossible to observe a significant decline of residues of these pesticides in the soil surface during the study. [...]
APA Style reference
For your bibliographyOnline reading
with our online readerContent validated
by our reading committee
