Maria Godoy

The study found the more often people visited the tanning bed, the higher the risk.

Those with 10 to 50 visits had twice the risk of melanoma.

If they had over 200 visits, their risk was more than eight times as high.

Study co-author Hunter Shane of the University of California, San Francisco says younger indoor tanners also had more DNA damage in their skin cells than people twice their age.

The findings appear in the journal Science Advances.

Maria Godoy, NPR News.

Hepatitis B is a virus that attacks the liver.

The disease can lead to liver cancer, cirrhosis, and death.

And the risks are much higher for people infected as infants.

Before the U.S.

began universally vaccinating newborns in 1991, some 18,000 children each year became infected before age 10.

About half were infected by their mothers at birth.

The other half got it from somewhere else.

The virus is found in blood and other bodily fluids, and it can live on surfaces for up to a week.

The risks are everywhere.

Infections have been documented at daycares, on sports teams, from shared toothbrushes and razors.

Since vaccination at birth became routine, hepatitis B case rates in the U.S.

have plummeted by 99%.

Since August, at least 15 infants in at least 12 states have been hospitalized with botulism after consuming ByHeart's infant formula.

No deaths have been reported.