Indoor air concentration of chlordane, and its seasonal variation

Recent decline of DDTs among several organochlorine pesticides in background air in East Asia

Hexachlorocyclohexanes (HCHs), chlordanes (CHLs), and dichlorodiphenyltrichloroethanes (DDTs) in air-mass outflows from East Asia were recorded monthly from April 2009 to March 2014 at Cape Hedo in Japan. These organochlorine pesticides (OCPs) were collected by a high volume air sampler equipped with a quartz fiber filter, a polyurethane foam plug, and activated carbon fiber and analyzed by using a gas chromatograph-high resolution mass spectrometer. The overall (and geometric mean ± SD) concentration over the period was 4.9-43 pg m(-3) (15 ± 7.8 pg m(-3)) in HCHs (sum of α-/β-/γ-/δ-HCH), 1.5-83 pg m(-3) (8.8 ± 11 pg m(-3)) in CHLs (sum of cis-/trans-chlordane, cis-/trans-nonachlor, and oxychlordane), and 0.71-16 pg m(-3) (2.5 ± 2.0 pg m(-3)) in DDTs (sum of o,p'-/p,p'-DDD, o,p'-/p,p'-DDE, and o,p'-/p,p'-DDT). Clear seasonal changes, i.e. higher in summer and lower in winter, were observed in HCHs and CHLs, suggesting the dominant effect of temperature-dependence, secondary sources in these OCPs. DDT concentration as well as the ratio of (o,p'-DDT + p,p'-DDT) to total DDTs, on the other hand, showed clear a declining trend during the five year sampling period, suggesting the decrease of input of newly produced DDTs in the regional environment by reflecting recent activities in the East Asian region to eliminate production and use of DDTs under the Stockholm Convention.

Tissue concentrations of chlordanes in mice after long-term exposures to technical grade chlordane at indoor air levels

We determined concentrations of chlordanes (5 chlordane compounds and 2 metabolites) in tissues and organs of mice following a prolonged exposure to Chlordane (technical grade chlordane) at levels as low as those in indoor air.After exposure to 4.22-11.36 μ g/m(3) Chlordane (total of 5 compounds) in the air for 1-6 months, 6.44-13.00 ppm chlordanes (total of 7 compounds) were detected in mice (2 tissues and 6 organs). The adipose tissue among the 2 tissues / 6 organs examined contained the highest chlordanes. The ratio of the adipose tissue chlordanes to the liver chlordanes was approximately 5.6 times, followed by the muscle (0.9), lungs (0.4), kidneys (0.4), heart (0.3), spleen (0.2) and brain (0.1). In addition, trans-nonachlor, oxychlordane and heptachlorepoxide in chlordanes were at a high level.The level of Chlordane exposure (dose) and the level of chlordanes accumulation in each tissue or organ of the mice except for the heart were closely correlated (r=0.9388-0.7130), and showed a linear relationship. The tendency of chlordanes accumulation in light of the linear relationship was adipose ≫ liver ≥ muscle.Thus, even with a low level of Chlordane in indoor air, chlordanes may be steadily accumulated in the bodies of human residents with prolonged exposure similarly. The present findings suggest that it is necessary to investigate die risk of organochlorine chemicals contamination in indoor air at prolonged exposure.