Impacts of dust storms on PCDD/Fs and regulated harmful matter in a basin area

Few studies have been conducted on the relationship between the high levels of dust particles and the concentrations of atmospheric PCDD/F during dust storm episodes. However, they did not investigate the impact of dust storm on basin areas. This present study shows the dust storm effect on regulated harmful matter and polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) concentrations in basin areas. The results indicate that the average PM10 (aerodynamic diameter less than 10 μm), SO2 (sulfur dioxide), NO2 (nitrogen oxides), CO (carbon monoxide) and O3 (ozone) levels during the dust storm were 5.14, 2.30, 1.44, 1.40 and 1.41 times higher than those before the dust storm, respectively. Mean PCDD/F concentrations during the dust storm (0.958 pg Nm−3; 0.0484 pg I-TEQ Nm−3) were significantly higher than those before the dust storm (0.240 pg Nm−3; 0.00705 pg I-TEQ Nm−3). The PCDDs concentration during the dust storm was 1.84 times larger than that before the dust storm, and the PCDFs concentration was 10.2 times larger. Therefore, the dominant contribution of PCDD/Fs concentration during dust storm in the basin areas of northern Taiwan is PCDFs. OCDD concentration measured before dust storm was the highest among the seventeen investigated PCDD/F congeners, accounting for about 64.6% of the total concentration. However, OCDD concentration measured during the dust storm was comparable with the OCDF among the seventeen investigated PCDD/F congeners, accounting for about 24.5% (OCDD) and 22.9% (OCDF) of the total concentration. The above results indicate that the impact of a dust storm on regulated harmful matter and PCDD/F concentrations in the basin area is significant. An investigation of the health risk from dust storms in basin areas is needed.