Organochlorine pesticide exposure and uptake following soil treatment of domestic premises

Abstract

Twenty-nine dwellings treated with aldrin, an organochlorine (OC) pesticide, in a standard manner for prevention of termite infestation, were repeatedly sampled over a two-year period for airborne aldrin concentrations. Air sampling was carried out under standardized conditions in an unventilated room. Periodic measurements were also made of blood dieldrin levels of one occupant of each dwelling. In ten of the dwellings there was no detectable airborne aldrin prior to treatment. After treatment aldrin concentration varied from 0.08 to 51 µg m -3 . One week following treatment, six dwellings had levels above 10 µg m -3 ; by six months only two dwellings were above this level.After one year, only one dwelling had an aldrin concentration above this level (27 µg m -3 ) and the concentration in that dwelling was still nearly the same after two years. This dwelling was also sampled three years post-treatment, by which time the concentration had declined to 12 µg m -3 .Statistical analysis of the blood dieldrin levels of the occupants as a group showed (1) an increase in blood dieldrin of borderline statistical significance, (2) a significant correlation with airborne aldrin levels in the respective occupants' homes, and (3) an effect of the aldrin treatment on blood dieldrin levels was detectable above the background influences of diet, physiological variation and laboratory technique. The statistically significant outcomes largely resulted from the data from the two most-heavily contaminated homes, whose occupants experienced a perceptible increase in blood dieldrin following the aldrin treatment, to a plateau of about 10 ng ml -1 after one year, declining after two years to above one-half of that level.The two subjects who showed a clear and sustained increase in blood dieldrin following treatment of their homes were estimated to have experienced uptakes of 54 and 63 mg, equivalent to a mean daily uptake respectively of 1.6 and 1.1 (xg kg" 1 body weight for two years.It is concluded that, even if OC treatment of houses is conducted in accordance with regulatory requirements, it is inevitable that some airborne aldrin will become detectable in the interior of the dwelling. In most cases, the treatment will have no measurable effect on the blood OC levels of the occupants. In the small number of cases where some OC uptake is detectable, the peak levels are likely to be insufficient to cause adverse health effects.

Case Study of Organochlorine Pesticides in the Indoor Air of a Home

“…The aldrin half-life of 16 months in this home can be compared to the value obtained by Gun et al (8), who measured indoor air aldrin concentrations for 24 months after treatment of 29 dwellings in Australia. Although Gun et al did not report a half-life directly, we were able to calculate it from the mean concentrations and sampling dates they reported.…”