Effects of changes in polycyclic aromatic hydrocarbons (PAHs) emissions and degradation on their concentrations in Tokyo from 2007 and 2016.

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in aerosol were measured in Shinjuku, which is central Tokyo, Japan, for 10 years from 2007 to 2016. The effects of changes in emission sources and their degradation by reaction with ozone were assessed in this study. There was no significant increasing or decreasing trend of the PAH concentrations during 10 years (P > 0.

Disentangling the contribution of the transboundary out-flow from the Asian continent to Tokyo, Japan.

We assessed the contribution of transboundary air pollutants (TAPs) transported from China to Tokyo using the Pb/Cu index. We conducted intensive observations over four seasons during 2014-2015 and analyzed ionic components and thirteen elements in size-segregated aerosols collected at the top of a 30-m-high tower in a hilly forested area of the Field Museum Tamakyuryo (FM Tama), in a western suburb of Tokyo. In order to evaluate if the Pb/Cu ratio can be applied in Tokyo as the megacity, the annual average concentration of Pb at Cape Hedo, Kumamoto city, on the west side of Japan, was higher than that of Pb at Tokyo, on the east side; this result indicates that TAPs affect western Japan more than eastern Japan.

Degradation of PAHs during long range transport based on simultaneous measurements at Tuoji Island, China, and at Fukue Island and Cape Hedo, Japan.

We investigated the degradation of polycyclic aromatic hydrocarbons (PAHs) during long-range transport. Aerosols were collected simultaneously at remote sites on Tuoji Island, China; Fukue Island, Japan; and the Cape Hedo Atmosphere and Aerosol Measurement Station (CHAAMS), Okinawa, Japan in April, October, and December from 2012 to 2013. These remote sites were convenient for investigating the degradation of PAHs during long-range transport.

Seasonal and annual changes in PAH concentrations in a remote site in the Pacific Ocean.

This paper reports the long term observation of particle-associated polycyclic aromatic hydrocarbons (PAHs) at Cape Hedo Atmosphere and Aerosol Monitoring Station, a remote site in the Western Pacific Ocean, from 2008 to 2015. This is the first long-term study that evaluated the contribution of long-range transport of PAHs in East Asia. No obvious trend (P > 0.