The health hazard of diesel engines has long been speculated, but has not yet been an official agenda on scientists’ tables.

However, a recent World Health Organization’s decision to name diesel fume a grade-1 cancer-causing substance has shed light on the fuel. According to the WHO International Agency for Research on Cancer, diesel fumes could potentially be as big a public health threat as secondhand smoke, increasing the chances of lung cancer and bladder cancer.

“We have studied bus and taxi drivers as well as those on the roads who are likely to be exposed to diesel fumes for a long period of time. We are not certain whether the period of time of exposure to the fume is relevant to health risks yet,” said Christopher Portier, the U.S. Centers for Disease Control and Prevention’s director of the National Center for Environmental Health and Agency for Toxic Substances and Disease Registry. He also highlighted research results showing minors being prone to developing cancer. 

At a press conference held in downtown Seoul Tuesday, Portier, who is also a member of IARC scientific committee, said that in the U.S., the chances of truck drivers developing respiratory diseases and other illnesses were 15-40 percent higher than ordinary people. He said that even pedestrians should be mindful of the facts. Wearing masks might help, as some medical experts claim, but Portier said it is uncertain and depends on the specifications.

He said what exactly affects the cancer prevalence is still unclear ― whether it is the engine or the fuel itself. He suspected sulfa to be the mostly likely culprit.

Portier stressed that installing a filter on the engine is a key solution to minimize the health risk.

“One thing for sure is that whether it is the fuel or the engine, emission of the harmful substance reduces by a great level when filters are installed,” he said.

Portier and National Cancer Center head Lee Jin-soo called for government and societal attention on the issue. The Korean administration has decided to elevate the diesel regulation level to that of Europe. U.S. authorities are also gearing up to minimize the problem ― a recent study suggested that the installation of filters could drop the toxin emission by one-millionth.

“We believe smoking accounts for more than 80 percent of lung cancer prevalence followed by hereditary or unknown factors. But still, with the slightest suspicion, we should be a little more aware of diesel fumes in the future,” Seo Hong-gwan, an NCC official, said.

“But we hope people will not panic because we do not know the exact cause-and-effect relations,” he added.

By Bae Ji-sook (baejisook@heraldcorp.com)