3. Occupational pesticide users – jobs associated with pesticide use
Occupational end users of pesticides include workers who are involved in the application of pesticides or who re-enter treated areas shortly after pesticide application. Such workers are mostly classifiable as (1) agricultural workers, (2) structural/urban pest controllers, or (3) municipal, public utilities, parks and gardens workers, and foresters. Each of these groups has distinctive pesticide exposure profiles due to differences in the context and purpose of pesticide use.
Agricultural workers are one of the major groups of pesticide-exposed workers. The types of pesticide, frequency of use, and application method vary according to the farm type and the commodities being grown. Although agricultural activity accounts for the majority of occupational pesticide use [10] and [11], farm pesticide use is generally an intermittent, seasonal task and only one of the wide range of tasks undertaken by farm workers [10] and [12]. Consequently, the exposure frequency and total exposure time among most farm workers are typically lower than for pesticide applicators in other industries [13]. Dedicated agricultural pesticide applicators have more frequent exposure than farm operators but may have fewer years of pesticide use [14]. Many of the published cohort studies of pesticide exposure and health effects have focused specifically on agricultural workers who are licensed pesticide users (e.g., [15], [16], [17], [18] and [19]). However, there is evidence suggesting that pesticide exposure may not be universal among farm workers, and a large proportion of workers in the farming sector may not be exposed to pesticides directly [20] and [21].
Dedicated nonagricultural pest control operators (structural or urban pest controllers) comprise a comparatively small fraction of the pesticide-exposed workforce, however, their exposure pattern is systematically different from that of agricultural pesticide applicators [22]. These nonagricultural pest controllers are exposed on a more regular basis because the application of pesticides is a central task of their job [23] and [24]. Another important difference is that nonagricultural pest controllers’ work is predominantly associated with built environments and applying pesticides indoors, including restricted spaces [25].
Other occupational pesticide users include turf workers, such as greenkeepers and other sports facilities caretakers, ornamental gardeners, and park workers who may use weedicides, fungicides, and insecticides to maintain turf and gardens [26]. Herbicide use is characteristic of workers involved in maintenance of public infrastructure and in particular clearance of vegetation from linear infrastructure corridors such as roads, railway lines, and overhead electrical distribution lines (line clearance) [26]. Line clearance and other vegetation control tasks using herbicides may also be common among forestry workers [27].