A STUDY OF BUILDING STRUCTURAL FEATURES ASSOCIATED WITH HIGH INDOOR AIR CONCENTRATIONS OF ORGANOCHLORINE TERMITICIDES

As part of a two-year study of post-treatment residential exposure to the termiticide, aldrin, the building structural features of ten house s with crawl-space-type floors were assessed by an independent inspect or. Building attributes recorded on a checklist included the age of th e dwelling, room characteristics, floor details and the nature of subf loor ventilation. At the end of each inspection, the inspector, who wa s blinded to data on airborne aldrin concentrations, providing a ratin g of expected indoor air contamination. Several of the building attrib utes, including age of the house, the area of exterior subfloor vents, as well as the inspector's rating, were significantly correlated with airborne aldrin values. No single building variable, however, was hig hly correlated with every measure of aldrin concentration over a 12-mo nth period. The observed data are consistent with poor subfloor ventil ation and a 'leaky' floor being important contributors to indoor air p ollution. It is recommended that pest control companies advise househo lders about any obvious floor and ventilation deficiencies before soil treatment work is undertaken. Pesticide exposure (by analogy with geo logical radon exposure) may be reduced by sealing gaps in floors and/o r by improving subfloor ventilation.