A chemical residue survey in relation to the 1930 spruce budworm spray program in New Brunswick (Canada)

Abstract

This paper describes the results from a pesticide residue survey conducted in relation to the 1980 spraying of insecticides in New Brunswick (Canada) to preserve the coniferous forest from an on-going spruce budworm infestation. A total of 465 water and air samples were collected from 12 sites throughout the Province. In water, fenitrothion was usually detected at about the same time that spraying occurred in the immediate area of the sites. The maximum that was ever detected was 20.0 ppb and persistence was usually limited to a few days except in a small pond where fenitrothion was detected for a total of 18 consecutive days. Aminofenitrothion was also detected at a maximum of 8.0 ppb. Fenitrothion was only detected occasionally in air samples the maximum being 1.2 ng/dm3. However, amino-fenitrothion was present in several air samples at a maximum of 12.0 ng/dm3.

Effect of fenitrothion on the foraging behavior of juvenile atlantic salmon

“…A maximum of 0.02 pl/L fenitrothion has been found in streams and ponds following commercial spray programs [2,3]. A maximum of 0.02 pl/L fenitrothion has been found in streams and ponds following commercial spray programs [2,3].…”

“…Fenitrothion [O,O dimethyl O-j3-methyl-4nitrophenol)phosphorothioate] is an organophosphate insecticide used in Canada to control the spruce budworm (Choristoneura fumlferuna) and the hemlock looper (Lambdina fiscellariu) [ 1,2] It is regularly sprayed in areas near Atlantic salmon rivers and ponds [2], creating the potential for exposure of salmon to this pesticide Exposures, if they occur, would almost invariably be to sublethal concentrations of the pesticide A maximum of 0 02 pl/L of fenitrothion has been found in waterways following spray operations employing buffer zones [2,3] Sublethal levels of fenitrothion are known to inhibit the activity of brain acetylchohnesterase, thereby disrupting synaptic transmission in the cholinergic part of the nervous system [4] This inhibition can cause severe behavioral changes such as decreasing the ability to forage efficiently Decreased foraging efficiency could lead to decreased growth or even death of the affected individuals [5] Fenitrothion is known to cause decreased foraging, as well as changes in dominance hierarchy and learning among salmonids [6-101 These effects were found when salmon were exposed to concentrations of fenitrothion near their 96-h LC50 and to a formulation of the pesticide no longer in wide-*To whom correspondence may be addressed spread use The purpose of this study was to examine the effects of fenitrothion, not only on overall feeding level but also on finer details of the foraging behavior of juvenile Atlantic salmon (Salmo salar) Foraging was examined following exposure, at concentrations well below the 96-h LC50 level, to technical grade fenitrothion and to an operational formulation of the pesticide that is currently in use in forestry operations in Canada…”

Recovery of foraging behavior of atlantic salmon exposed to a simulated commercial application of fenitrothion

“…The maximum level of fenitrothion that has been detected in stream and pond waters, following normal spray operations employing buffer zones, is approximately 20 pg/L [2,7]. The maximum level of fenitrothion that has been detected in stream and pond waters, following normal spray operations employing buffer zones, is approximately 20 pg/L [2,7].…”

“…In a commercial spray program, fish may receive two exposures to organophosphate insecticides because the usual procedure is to spray an area twice, from the air, with 5 to 7 d separating applications of the pesticide. The maximum level of fenitrothion that has been detected in stream and pond waters, following normal spray operations employing buffer zones, is approximately 20 pg/L [2,7]. This is a concentration that is well below the 96-h LC50 level for most fishes.…”

Persistence characteristics of operationally sprayed fenitrothion in nearby unsprayed areas of a conifer forest ecosystem in New Brunswick

“…Some of the earlier data reported on fenitrothion persistence were gathered during the operational spraying. Consequently, indirect entry of the chemical via drift into the sampling sites has been considered as a possibility (Pearce et al, 1979;Mallet and Volpe, 1982;Sundaram, 1984b). Therefore, definitive information was lacking on the residue component arising from the prolonged persistence of the chemical due to replicate applications over the years, and the residue component …”