The residents of a Napier suburb, built on top of an old rubbish dump, may be risking their health, experts say. City council tests conducted in the suburb's park over a year ago found toxic substances exceeding allowable levels, but the residents were only officially told this week. The old landfill in Onekawa was closed in the late 1950s. Since then 125 homes and a park have been built on the site. …