One focus of SEPA’s subprogram for human biological data concerns metals in human bodies (Table 4, #9.1). It includes studies on lead concentration in human blood, mercury in hair, and cadmium concentration in urine. Old hair samples have been collected and analyzed for mercury. Methyl mercury may damage the central nervous system, and at the fetal stage effects may occur already after low exposure. A study in Uppsala is investigating persistent organic compounds in breast milk. Concurrently, the young mothers answer a questionnaire, and hair samples are collected to analyze methyl mercury. Cadmium in urine is an indicator of the load on kidneys, and especially women with low iron storage have an elevated risk for increased cadmium uptake. A program on cadmium in women that started in Gothenburg, then expanded to Stockholm, Lund, and Umeå is under way. In 2007, a second round started in Gothenburg. A questionnaire is filled in concurrently with collection of a urine sample.