Recently, the World Health Organization’s International Agency for Research on Cancer (IARC) concluded, after eight days of deliberating, that diesel exhaust ranks as a Class 1 carcinogen. In other words it’s been lumped in the same category as the likes of asbestos and mustard gas and considered a significant cancer risk.
The IARC arrived at that conclusion by using data from studies of workers that operated in close proximity to diesel exhaust, particularly a larger cohort study released back in March, that highlighted the prolonged exposure of diesel exhaust to 12,315 miners working in the U.S.
However, critics of the findings quite rightly point out that much of the data used was out of date and not reflective of the general population. The National Cancer Institute in the U.S., said research from “heavy exposure” to diesel exhaust in confined areas such as underground mining “cannot estimate with certainty the risks from diesel exposure for very low levels of pollution in the general environment.”
Additionally, Allen Schaeffer, executive director for the Diesel Technology Forum, says the WHO studies were based on diesel-powered equipment manufactured before the EPA began aggressively mandating reductions in diesel exhaust emissions in 2002.
“In the U.S., emissions from heavy-duty diesel trucks and buses have been reduced by 99 percent for nitrogen oxides and 98 percent for particulate emissions,” he said. In the U.S., the EPA indicates that diesel accounts for less than 6 percent of all particulate matter in the air.”
Even the EPA itself officially claims a 90 percent reduction in diesel exhaust emissions over the last decade, not only from cars, buses and trucks (like the Western Star dumper) seen here but also from other motorized vehicles such as ships and locomotives.
So, given this on balance, plus the fact that even the WHO admits modern formulation processes and emissions controls have “reduced the amount of particulates and chemicals” and the WHO has further said “it is not yet clear how the quantitative and qualitative changes may translate into altered health effects,” it essentially makes one ponder why the WHO would issue such a sweeping statement against diesel in the first place.
What do you think?