POLLUTION SOURCE: Breathing metals, like from this nickel smelter, may put stress on the heart and lungs.
WIKIMEDIA COMMONS/P199

Mort Lippmann noticed a strange phenomenon in his laboratory mice. For 14 straight days, their hearts were racing.

Lippmann, a scientist at New York University who has studied the effects of air pollution for over 50 years, couldn’t explain it. During those two weeks in October, 2004, air pollution levels were lower than average at his laboratory in Tuxedo, New York, 30 miles north of New York City.

But Lippmann soon learned that concentrations of tiny particles of nickel were the highest he’d ever seen. He tracked them all the way to a nickel smelter in Ontario, Canada, about 500 miles away.

Now Lippmann and his colleagues have gathered evidence suggesting that it’s not just mice that are affected by the metallic particles. They observed that both concentrations of airborne nickel and daily deaths from heart disease were much higher in New York City than any other city in the United States.

Around the world, fine particles – smaller than a few microns in diameter – have been linked to increased hospitalizations and deaths from cardiovascular and respiratory diseases within hours to days of exposure.

But new evidence is emerging that some particles in the air may be more dangerous than others.

A growing body of animal and human research suggests that breathing metals may put acute stress on the lungs and heart, resulting in illnesses and deaths at particulate levels below national standards.

“There’s all kinds of evidence that the toxicity and composition of airborne particles vary from one city to another. In New York, airborne nickel, present even at a small concentration, is particularly influential,” said Lippmann, a professor of environmental medicine who directs the federally funded Particulate Matter Health Effects Research Center at NYU.

Residual oil, known as bunker fuel, is the main cause of New York City’s high levels of nickel and another metal, vanadium. Space heaters in older apartment buildings often burn the cheap form of crude oil, which also is used to fuel ships.

Although the metals may be highest in New York, studies show that hospitalizations across the country increase with metals in the air.