An investigation of the disposal of fumigation pesticide residues in Zambia

Abstract

Fumigation involves the use of a highly toxic pesticide which leaves behind residues that are classified as hazardous wastes. Such wastes enter our environment owing to improper disposal that pose a huge threat to public health and the environment at large. This study explored the disposal of fumigation pesticide residues in Zambia. It aimed at assessing the chemical composition of the fumigant residues to be disposed of, methods of disposal of fumigation pesticide residues being practiced in Zambia and to what extent fumigators comply with Zambian environmental regulations. A mixed- method approach was used and purposive sampling helped in establishing the study location. Laboratory tests were conducted using the X-Ray Fluorescence at the Zambia Bureau of Standards Laboratory for 25 samples, collected from 15 districts along the line of rail, from Livingstone to Chingola. 25 fumigators and 50 assistants conducting fumigation in Southern, Lusaka, Central and Copperbelt provinces participated in the study. Results obtained were analyzed using the Statistical Software version 20 (SPSS) alongside Excel 2010. The findings revealed that only 22 % always buried the fumigant residues in a 1-meter-deep pit. However, through observations, 17 fumigators from the 15 districts disposed the fumigant residues on open surfaces despite being aware of the environmental regulations. On the other hand, the Zambia Environmental Management Agency visited only 48 % of fumigators’ premises. The mean standard deviation of the Provincial Laboratory results were as follows: Southern 1692 ppm; Copperbelt 11608 ppm; Central 13901 ppm and Lusaka 10339 ppm. All results were below the lower flammable limit of 18000 ppm of aluminium phosphide in fumigant residues. However, samples from three districts gave values more than the 2000 ppm allowable level for human safety. The findings also showed that only 21 % of fumigators were compliant with the law in their disposal methods while the remaining 79 % were non-compliant. Though fumigators were trained before engaging in fumigation activities, they took little useful action for safe disposal of fumigant residues. Findings in this study require immediate attention by the government through Zambia Environmental Management Agency to develop policies that will help abolish unsafe disposal of fumigation pesticide residues. Further, trained fumigators and not their assistants should conduct disposal of fumigant residues. Zambia Environmental Management Agency should intensify their inspections to ensure the law is enforced and standard fumigant disposal protocols must be devised and made available to the fumigators. Key words: Fumigants, Residues, Pesticides, Disposal, Compliance.