A large study has found that children of women who ate little fish during pregnancy had lower IQs and more behavioral and social problems than youngsters whose mothers ate plenty of seafood, a finding that challenges the US government's standard advice to limit seafood while pregnant. The advice to limit seafood consumption is based on concerns that children might absorb too much methyl mercury(メチル水銀), which builds up in fish and can cause neurological(神経病の)problems.