Pursuant to Proposition 65, lead was listed as a male and female developmental reproductive toxicant on February 27, 1988 and lead and lead compounds were listed as carcinogens on October 1, 1992. Due to the high toxicity of lead, the maximum allowable dose level for lead is 0.5 ug/day which is more stringent than any other reproductive toxicant listed under the statute.
Effects of Lead Exposure
In addition to being classified as a Proposition 65 listed chemical, there is considerable medical literature regarding other health effects from exposure to lead. While lead exposure is harmful to people of all ages, it can be especially damaging to the health of children, fetuses and women of childbearing age. Lead exposure before or during pregnancy can alter fetal development and cause miscarriages. Since 1978, the Center for Disease Control has lowered the blood lead level of concern from 60ug/dL to 10 ug/dL. Blood lead levels as low as 10 ug/dL have been associated with learning disabilities, growth impairment, permanent hearing and visual impairment and other damage to the brain and nervous system.
Epidemiological studies demonstrate that, at low lead levels, neurodevelopmental effects occur in children and that children are more sensitive to the neurotoxic effects of lead than are adults. Low lead levels have been associated with developmental delays and lower intelligence, short term memory, perception integration, visual motor functioning, and behavior in children.
It has become apparent that there is no safe level of exposure to lead. Recent studies indicate that the level of concern is not low enough and public health agencies are taking notice. Most recently, the Office of Environmental Health Hazard Assessment (OEHHA) of the California Environmental Protection Agency has replaced the 10 µg/dL "level of concern" with a source-specific "benchmark change" of 1 µg/dL.
At the federal level, on October 15, 2008, the Environmental Protection Agency (“EPA”) substantially tightened the national ambient air quality standards (“NAAQS”) for inhaling lead. The EPA has revised the level of the primary (health based) standard from 1.5 micrograms per cubic meter to 0.15 microgram per cubic meter - a ten-fold strengthening of the level of concern. While this case involves the more significant route of exposure, namely ingestion, it is important to note that EPA's new rule is based on more than 6,000 new studies on the health effects from lead exposure that have been published since 1990. These health studies indicate that adverse effects occur at substantially lower levels of lead in the blood than previously believed.