The health effects of arsenic are well documented. Why would there not be an adverse health effect from their presence in Sudbury soils?
While there is arsenic present in the soil, testing has not revealed any concentrations specifically in soils that would pose a human health concern. In most cases, human exposure to arsenic is low. In the case of environmental exposure to substances in the soil, the high-dose effects that may give rise to toxicity are unlikely, that is, toxic effects are seen at high levels of exposure, not at low levels.
