Researchers have found that that can harm ecosystems and human health.
Most scientists presumed mercury deposited from the atmosphere came either from raindrops or via "dry deposition." Now, field experiments conducted by Peter Weiss-Penzias at the University of California, Santa Cruz, and his colleagues have identified another atmospheric source of mercury that's likely to be substantial in some areas, especially along some coasts.
At four locations near Monterey Bay, the researchers collected large volumes of fog droplets from June through August 2011. In 25 samples, concentrations of all forms of mercury averaged 10.7 nanograms per liter, and levels of monomethyl mercury averaged 3.4 nanograms per liter, they reported last month in Geophysical Research Letters. Weiss-Penzias notes that the latter concentration, the first such measurement ever reported from fog water, "is about five times the highest concentration ever seen in rainwater."
A full-term pregnancy with a small baby may cause changes in a woman's cardiovascular system that increase her risk for heart disease later in life, new data suggest.
Researchers at the University of Texas Medical Branch in Galveston studied 6,608 women who had delivered full-term babies, 309 of them under the threshold weight, 5 pounds 8 ounces. Women who had had small babies were at about twice the risk for heart disease as those who had not, the researchers found. The study, published in the March issue of PLoS One, adjusted for age, diet, physical activity, hypertension, stroke, diabetes, family history and other known risks, but the association persisted.
The study could not explain the cause, but one possible factor was that delivery of small babies is associated with a reduction in placental hormones that stimulate blood vessel repair.
A man who drinks one 12-ounce sugar-sweetened drink a day sharply increases his risk for heart disease, said an epidemiological analysis published in the journal Circulation. Harvard researchers analyzed data from a prospective study of 42,883 male health professionals, ages 40 to 75. The men responded to questionnaires every four years, and more than 18,000 of them provided blood samples.
Over 22 years, 3,683 of the men had heart attacks. Even after controlling for such factors as smoking, exercise and family history, the scientists found that men who drank the sweetened drinks most often were 20 percent more likely to have had a heart attack than those who drank the least.