Publications by authors named "Don Waite"

This study quantified the masses of 14 pesticides deposited as wet (precipitation) versus dry (gaseous and particle) atmospheric deposition at a research farm in southwestern Manitoba, Canada. The concentration in air of these pesticides was also measured. Total bulk deposition amounts (wet+dry) ranged from 0.

View Article and Find Full Text PDF

The Canadian Atmospheric Network for Currently Used Pesticides (CANCUP) was the first comprehensive, nationwide air surveillance study of pesticides in Canada. This paper presentsthe atmospheric occurrence and distribution of pesticides including organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), acid herbicides (AHs), and neutral herbicides (NHs) during the spring to summer of 2004 and 2005 across agricultural regions in Canada. Atmospheric concentrations of pesticides varied within years and time periods, and regional characteristics were observed including the following: (i) highest air concentrations of several herbicides (e.

View Article and Find Full Text PDF

Atmospheric loadings of gamma-hexachlorocyclohexane (gamma-HCH) from May 1, 1998, to April 30, 1999, to the Great Lakes simulated by a coupled soil-air and water-air atmospheric transport model are presented. Modeling results on an annual basis indicate that Lake Superior received the highest dry deposition load of 2.17 kg yr(-1).

View Article and Find Full Text PDF

The presence of several anthropogenic chemicals has been documented in the atmosphere of the Canadian prairies. The deposition of these chemicals as a mixture is of importance since little is known of the combined effects of these chemicals on aquatic organisms. This study was designed to evaluate the acute and chronic toxicity of a complex mixture of nine atmospherically transported pesticides to Ceriodaphnia dubia.

View Article and Find Full Text PDF

Triclopyr is nonpersistent in surface water. It has limited mobility and low to medium persistence in soil. Considering its adsorptive characteristics and that it dissipates via multiple pathways, such as photolysis, plant metabolism, and microbial degradation, its potential to leach to depth in soil and to contaminate groundwater is low.

View Article and Find Full Text PDF