and his coauthors summarize the current state of knowledge about
trans-Pacific transport of pollutants from Asia and Europe to North
America. While they comment that the available data paint only a
sketchy overall picture, they report that several different types
of pollutants are now known to be carried by wind currents across
the Pacific. These include persistent organic pollutants (POPS),
heavy metals such as mercury, ozone and coal combustion products.
movement eastward from Asia is highest in winter and spring. Depending
upon altitude and weather, transit times across the ocean can be
5 to 10 days.
few data available indicate that pollutants arrive on the west coast
of North America in bursts, as polluted air masses work eastward
across the ocean. Computer simulations suggest that three to five
of these "important pollution events" reach the US and
Canadian west coasts each year between February and May.
plume of air moves across the Pacific Ocean from central Asia
in Spring 1998. Graphic from Wilkening et al. 2000.
on contaminant accumulation in natural habitats, sediments, wildlife
and people indicate that at least some of the transported pollutants
are "working their way into ecosystems and humans." Wilkening
et al. cite one report concluding that anticipated growth in Asian
ozone from fossil fuel combustions may even make ozone standard
attainment in US population centers more difficult.
expected economic expansion around the Pacific Rim and in the
rest of the world will deliver even more pollution unless preventative
measures are taken. The risk of adverse effects to wildlife,
ecosystems, climate, and human health throughout the Pacific
region will increase. Even remote areas such as Arctic and alpine
environments are threatened. Ocean productivity and the atmospheric
energy budget over the North Pacific Ocean could be altered."