I haven't yet read any studies directly linking mercury and sleep apnea, but, mercury is linked to asthma and allergies and also various neurological problems, so there may be a connection. If anyone has any specific information, I'd be very interested.

In the meantime, you could try taking lots of Vitamin C, Vitamin E with Selenium, and Algin (the "big 3" for mercury toxicity). Magnesium deficiency is also linked with various respiratory problems, as well as some sleep disturbances.

If I do come across any other information, I'll be sure to post it.