http://www.nytimes.com/2008/01/23/dining/23sushi.html?hp
这段讲老中的挺有趣。国内生的和有钱的老中血汞特高。

A number of studies have found high blood mercury levels in people eating a diet rich in seafood. According to a 2007 survey by the New York City Department of Health and Mental Hygiene, the average level of mercury in New Yorkers’ blood is three times higher than the national average. The report found especially high levels among Asian New Yorkers, especially foreign-born Chinese, and people with high incomes. The report noted that Asians tend to eat more seafood, and it speculated that wealthier people favored fish, like swordfish and bluefin tuna, that happen to have higher mercury levels.