Health and medicine in brief

Diesel exhaust may cause lung cancer, study finds

The Environmental Protection Agency concluded Tuesday that long-term exposure to exhaust from diesel engines likely causes lung cancer in humans and triggers a variety of other lung and respiratory illnesses.

The study, the culmination of decades of research, highlights the health problems posed by the complex mix of gases and fine particles emitted by heavy-duty diesel engines operating on the nation's highways, farms and construction sites.

"Overall, the evidence for a potential cancer hazard to humans resulting from chronic inhalation exposure to (diesel emissions) is persuasive," the report states.

The study, involving tests on occupational exposure and on animals, focused on diesel engines manufactured before the mid 1990s, when the government began pressing for tougher emission standards. With new engine and fuel technology expected to produce significantly cleaner engine exhaust by 2007, experts project a 90 percent reduction, from today's levels, in health-threatening exhaust particles from on-road vehicles.

"The agency expects significant environmental and public health benefits as the environmental performance of diesel engines and diesel fuels improves," said Paul Gilman of EPA's Office of Research and Development.

Although the EPA's final assessment echoes preliminary agency findings and other documents from various world health organizations and studies in California, it provides added urgency to efforts by the EPA and others to tighten diesel emission standards under the Clean Air Act.

A federal appeals court in May unanimously upheld a Clinton administration regulation requiring a speedy and dramatic reduction in pollution from large trucks and buses. That rule -- strongly contested by truck manufacturers and diesel fuel refiners because of the associated costs -- would cut emissions of particulate matter by 90 percent and nitrogen oxides by 95 percent, beginning in 2007.

The Bush administration has largely taken a strong stand in support of the tougher emissions standards. Last month, the White House and EPA rejected a plea from House Speaker J. Dennis Hastert, R-Ill., and other lawmakers to postpone the new anti-pollution standards for long-haul diesel trucks. The standards will provide stiff penalties for engine manufacturers that don't meet an October deadline for compliance under a consent decree.

The administration has also announced it will increase efforts to regulate emissions from off-road diesel-driven machinery and equipment, such as farm equipment and earth movers. A study by state air pollution control officials found that more than 8,500 premature deaths are caused annually by extraordinarily high levels of air pollution from such machinery.

Chaotic heart beat more likely in winter

BERLIN -- The likelihood of being admitted to hospital or dying with atrial fibrillation, a life-threatening chaotic heartbeat common among the elderly, increases dramatically during winter months, new research indicates.

A study found that among people aged 75-84, hospital admissions for atrial fibrillation were 25 percent higher than average in the winter, and nearly 40 percent higher than normal for those 85 and older.

The study, presented this week at a meeting of the European Society of Cardiology, also found that deaths from the condition were higher in winter.

The doctors' advice: stay warm, get a flu shot and stay sober.

The disorder affects people of all ages, but is particularly common among the elderly. It afflicts about 10 percent of people older than 75, including 2-million in the United States.

With an aging population and a greater proportion of people surviving heart attacks, experts predict that the number of cases of atrial fibrillation is likely to increase in the next decade.

"Given the almost universal problem of peak winter demands on hospitals in almost all countries with variable climatic conditions and the likelihood of an epidemic of atrial fibrillation in the near future, these represent significant findings," said Dr. Simon Stewart, the study's lead investigator.

"It is possible, for example, that greater efforts can be made to warn high risk patients of the dangers of inadequate heating and clothing, the need for flu vaccinations and the need to limit alcohol intake," said Stewart, a professor of cardiology at the Queen Elizabeth Hospital in Adelaide, Australia.

"As atrial fibrillation is often a precursor to stroke and heart failure -- two of the most costly, deadly and disabling of diseases -- the potential to save lives, and money, is enormous," he said.

Researchers have already determined that heart attacks, heart failure and heart-related sudden deaths are more common in winter.

Although experts were not surprised at the findings, they said the study is the first to document a seasonal influence on chaotic heart rhythm.

Atrial fibrillation occurs when the two small upper chambers of the heart (the atria) quiver instead of beating effectively. Blood isn't pumped completely out of them, so it may pool and clot. Clots that travel to the brain can cause strokes.

The disturbances can last anywhere from a few seconds to a lifetime.

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