Operator Hazards in Toxic Waste Disposal

Abstract

The nature of dangers (excluding radio-activity and simple accidents) to workers engaged in the disposal cf solid toxic waste were investigated. Two methods were used: 1) Site visits involving inspections and measurements; 2) Experimental and theoretical studies, involving laboratory and wind tunnel experiments and mathematical modelling. Consideration was given to the characteristics of the waste disposal industry, the hazards inherent in the current low cost operations and the important influence of legislation. A scoring system was used to grade selected sites according to their safety rating. Unsatisfactory conditions were noted on many sites, but there was some improvement over the period of the study. Analysis was maae of the applicability of quantitative risk criteria to waste disposal operations, specific safety training systems and codes of practice. Mathematical modelling of evaporation of solvents from pools provided generation rates which were extrapolated to provide likely down wind concentrations on sites. A critical distance formula and simple relationship were evaluated for the specification of safe distances from certain waste disposal operations. Laboratory experiments to ascertain toxic gas generation rates provided data which was used in wind tunnel experiments on models of typical road tankers to check the veracity of calculations on dispersion patterns. It was concluded that the potential existed for serious hazards to operators; many of the difficulties encountered were due to the constraints imposed by the highly competitive nature of the waste disposal operations. A lack of positive identification of wastes and the generally uncontrolled nature of waste handling operations were major problems. There was also over-reliance on open air operation to disperse potentially harmful gases or dusts. Outline recommendations were made for legislation governing operator safety and a field kit was developed to facilitate checks on the nature of deposited waste. Recommendations were made for further work to accumulate data on site hazards, to produce codes of practice, to improve training schemes and to extend the study to environmental impact considerations.