Comprehensive target analysis of micropollutants in soil at debris storage sites of the Kumamoto earthquake

ABSTRACT On April 16, 2016, a series of earthquakes with a maximum magnitude of 7.0 struck Kumamoto Prefecture, Japan, and about 1,300,000 metric tons of land-derived debris (building materials, household appliances, furniture, and wood) required disposal. Because public lands were used as emergency debris storage sites, environmental contamination by organic micropollutants from the debris has been a public concern. To identify chemicals of concern in the soil, our research group used a novel scheme in the combination of comprehensive target analysis (CTA) with an automated identification and quantification system (AIQS) that made use of gas chromatography–mass spectrometry (GC-MS). CTA-AIQS identified a total of 120 organic micropollutants in the soil samples from the debris storage sites. The predominant chemical groups in debris soils were PAHs, plasticizers, and pesticides. Higher concentrations of pesticides (insecticides and fungicides) were detected in soil under waste wood because those chemicals were used as wood preservation and termiticides. Estimated hazard quotients of the detected chemicals via soil ingestion by children (a high-risk group) suggested that the health risk was probably negligible. It was concluded that CTA-AIQS would be a useful tool for emergencies such as natural disasters.