Long-term Sampling of Atmospheric Dioxins Using a High-volume Air Sampler

Abstract

Dioxins (PCDDs, PCDFs and Co-PCBs) in ambient air are collected using a high-volume air sampler (HVAS) equipped with a quartz fiber filter (QFF) and two polyurethane foams (PUF). The air samples are usually collected at a rate of 100 L/min for 7 days in Japan. In recent years, the concentration of dioxins in the air has been decreasing, making it difficult to obtain accurate concentrations and congener compositions. It is assumed that extending the sampling period would result in more accurate measurements by lowering the lower limit of detection and provide more accurate annual average concentrations. Therefore, we investigated how long the sampling period could be extended without loss of atmospheric dioxins. As a result, it was found that dioxins could be collected without loss for one-month sampling. Even during the three-month sampling period, atmospheric dioxins were collected almost without loss—the recovery rate of some volatile sampling spike compounds decreased during the summer months. Except for the summer months when temperatures are high, atmospheric dioxins can be collected without loss, even if the collection is performed for a six-month period. Even in long-term sampling, the adequate collection of dioxins in the air can be evaluated with a good recovery of sampling spikes—preferably with the addition of TeCB-#79, which is more easily lost.