DEAR DR. DONOHUE: In the past few years, we have heard about mercury in fish. My husband is an avid fisherman. We have been told to limit our intake of fish. Can you tell me if I should put a limit on how often he eats fish? He has it about once a week. Is this going to catch up with him someday? – J.V.

ANSWER: Mercury finds its way into all rivers, lakes and oceans from sediment formed through erosion, undersea volcanoes and industrial pollution. All fish have a little mercury in them. Only a few larger, predatory fish pose a health threat. Numbered among those fish are shark, swordfish, king mackerel and tilefish.

Such fish should be eaten rarely, if at all. Young children and pregnant or nursing women should avoid them entirely, and they should limit their weekly fish consumption of all fish to 12 ounces.

People should not eat freshwater fish from lakes or rivers under fishing advisories due to pollution. You can find where those bodies of water are located by contacting your state’s Department of Community Health, Department of Public Health or Department of Natural Resources.

For excellent general information on fish and mercury, the Environmental Protection Agency has a Fish Advisory Web site – If you don’t own a computer, your local library can help you obtain this information.

There’s much good to be said about eating fish. The omega-3 fatty acids in fish lower cholesterol and provide protection against heart attacks and strokes. Furthermore, fish is a relatively low-calorie food. Ounce for ounce, it has fewer calories and saturated fats than meat and poultry.

Your husband is not going to get into trouble by eating fish once a week. People are encouraged to have fish at least twice a week. Just have him check with his state’s appropriate department about the water quality of the places where he fishes.

DEAR DR. DONOHUE: In September I was diagnosed with a pulmonary embolus. I was on a long driving holiday, yet I thought I was walking around fairly frequently. I am now on warfarin (Coumadin) daily. Are there any concerns I need to be aware of while on this medication? I have been told I will be taking it for six months. If I go off of it, do I need to be more concerned about having another recurrence? – B.B.

ANSWER: A pulmonary embolus is a piece of clot that has broken free from a large clot in a distant vein. Usually, that vein is a leg vein. The piece has been swept by the circulation into the lungs’ blood vessels, where it can occlude blood flow to the lungs. A large pulmonary embolus can kill.

People who have had one episode of a pulmonary embolus usually are put on six months of anticoagulation (thinning the blood to prevent clot formation) if the episode occurred from a known cause. Known causes are things like trauma and immobilization after surgery. Sitting in a car, airplane or train for long periods of time causes blood to stagnate in leg veins. Stagnant blood forms clots. Even though you stopped to walk during your drive, you must not have stopped as much as you should have. If you take another long road trip, make sure you do. Your doctor has you in the “known cause” category.

People who have had a pulmonary embolus without being able to find a precipitating event take anticoagulants for six months and then are often put on a lower dose of anticoagulants indefinitely. They have a greater risk of having another episode.

The concern for people on anticoagulants is bleeding, since their ability to form a clot has deliberately been altered by medication. So long as you take the blood tests that show you are not getting too much medicine, a dangerous bleed is not likely.

DEAR DR. DONOHUE: I am a 67-year-old woman who never has been pregnant. I understand this puts me at greater risk for breast and ovarian cancer. Should I have my ovaries removed? – R.M.

ANSWER: The chances of getting breast and ovarian cancer for women who never had children are slightly greater than they are for other women. No one, however, has ever suggested that such women have their ovaries removed as a preventive step.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from

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