Doctors treating patients along the Gulf Coast should be on the lookout for health effects from the oil spill, two U.S. health experts say in Monday's online issue of the Journal of the American Medical Association.

"The oil spill in the Gulf of Mexico poses direct threats to human health from inhalation or dermal contact with the oil and dispersant chemicals, and indirect threats to seafood safety and mental health," wrote Dr. Gina Soloman and Dr. Sarah Janssen in a commentary for the journal.

Both are with the department of medicine at the University of California at San Francisco and serve as senior health scientists with the environmental advocacy group Natural Resources Defense Council.

"Physicians should be familiar with health effects from oil spills to appropriately advise, diagnose and treat patients who live and work along the Gulf Coast or wherever a major oil spill occurs," the authors wrote.

Studies after previous oil spills such as the 1989 Exxon Valdez spill in Alaska showed that contact with oil can affect the lungs, kidneys and liver and have harmful mental health effects up to six years after the spill.

Soloman's concerns for the Gulf spill in order of priority are:

• Air quality, particularly during the leak itself.
• Skin contact with oil.
• Mental health issues.
• Oil contamination of seafood.

Levels of some pollutants so far may cause temporary eye, nose or throat irritation, nausea, headaches but are not thought to be high enough to cause long-term harm, an analysis by the U.S. Centers for Disease Control and Prevention concluded.

Doctors should be aware of the toxicity from exposure to oil and related chemicals such as dispersants, Soloman and Janssen said.

To prevent illness, the authors recommended that clean-up workers get proper training and equipment like boots, gloves, coveralls and safety glasses, as well as respirators when there are potentially hazardous levels of airborne vapours.

Residents of the area should not fish in off-limit areas or where there's signs of oil, and any fish or shellfish with an oily odour should be thrown out, the authors said.