Abstract
Trace compounds present in gas from six landfill sites have been identified and their concentrations measured. At least 100 components are present including hydrocarbons, esters, terpenes and organic sulphur compounds. In domestic waste sites these varied with the age of the refuse. Industrial waste sites evolved gas much richer in hydrocarbons and solvents including halocarbons. Vinyl chloride and benzene were also present in significant concentrations. A 100-fold dilution would be advisable to eliminate any long-term health hazard. Domestic waste sites do not pose a health hazard due to minor components although a 1,000,000-fold dilution is required to bring some of them below the odour threshold. At most sites, hydrogen sulphide was not a significant contributor to smell.