The Canaries Dropped from the Skies For two years, the transport of mined lead into a seaside Australian community was an unrecognized source of contamination. Then thousands of birds began to drop dead out of the sky.
Scientists discovered lethal amounts of lead in the dead birds. These birds were killed by drinking water that had been contaminated by lead carbonate. Lead carbonate is much more toxic than other forms of lead; it easily infiltrates the lungs and is rapidly absorbed by the blood. It was also the type of lead found in the local Australian mine.
The researchers went on to discover massive contamination of the local populace through breathing in lead carbonate dust; the contamination was also in the soil that grew their vegetables and in their drinking water. Lead carbonate from the mine comprised between 30 and 93% of the total blood lead content in children younger than 6. The effects of lead toxicity include neurological, cardiovascular, and reproductive damage. In addition, lead has been linked to high blood pressure.