A five-decade study of U.S. women has found that those exposed to high levels of the pesticide DDT in the womb were four times as likely to get breast cancer.

The study is the first of its kind to directly link breast cancer in humans to DDT, which was banned in many countries decades ago but continues to be used widely in Africa and Asia.

Experts at a top fertility conference are dismayed at the case of a German woman who after having 13 children has had IVF quadruplets at the age of 65.

The episode damages the reputation of in-vitro fertilization (IVF), which has enabled millions to know the joy of parenthood, they said.

The MERS outbreak raging in South Korea should be a "wakeup call", the World Health Organization said Wednesday, urging countries to be more vigilant since diseases can spread quickly in a globalized world.

The warning came as South Korea reported its 20th death from the Middle East Respiratory Syndrome virus, and amid rising concern that authorities will not be able to contain the outbreak.

Partially hydrogenated oils, known as trans fats, are not safe to eat and must be removed from the food supply in the next three years, U.S. regulators said Tuesday.

The announcement by the U.S. Food and Drug Administration finalized the agency's proposed ban on artificial trans fats in 2013, and described partially hydrogenated oils (PHOs) as not "generally recognized as safe" for use in human food.

A 65-year-old German man died this month of complications from a MERS infection contracted during a trip to the Arabian Peninsula in February, a German regional health ministry said Tuesday.

The man died in the western town of Ostercappeln on June 6 of a lung disease, the health ministry of Lower Saxony state said. 

New research has added to tentative evidence that eating chocolate in modest quantities may be good for the heart, its investigators said on Tuesday.

Scientists in Britain looked at data from nearly 21,000 people who filled out questionnaires about their lifestyle, and had their health monitored for more than 11 years.

South Korea Tuesday reported three more fatalities from the MERS outbreak but health authorities said they were cautiously optimistic the worst was over as the number of new cases was falling.

Four new cases were confirmed Tuesday, bringing to 154 the total number of confirmed cases with 19 deaths in what has become the largest outbreak of the virus outside Saudi Arabia.

Smoking is responsible for nearly half of deaths due to certain types of cancers in 2011, a U.S. study said Monday.

Some 48.5 percent of nearly 346,000 deaths attributed to one of the 12 types of cancer known to be caused by smoking were due to cigarette use, according to the study published online in JAMA Internal Medicine.

U.S. Secretary of State John Kerry is taking nothing more than Tylenol for his broken leg following his low-speed bike accident, he said in an interview published Sunday.

Kerry, who remains deeply engaged in the Iranian nuclear talks that have taken place over the past 18 months, told the Boston Globe that the narcotics doctors prescribed for him were having undesired effects. 

South Korea reported Monday its 16th death and five new cases in the growing outbreak of MERS which has placed more than 5,200 people under quarantine and sparked widespread alarm.

The death of a 58-year-old man put the total number of fatalities from Middle East Respiratory Syndrome at 16 since the outbreak began less a month ago.