Despite improving compliance, areas in 15 states are still failing to make the grade on federal air-quality standards for lead, the Environmental Protection Agency reports.
Monitoring data for 2008 to 2010 show the majority of states in compliance with National Ambient Air Quality Standards for lead, established in 2008, EPA announced Wednesday (Nov. 9).
On the other hand, the agency reported:
• Illinois, Iowa, Kansas, Michigan and Puerto Rico each have one area that does not meet the standard;
• Three areas in Tennessee, Arizona and New York are still considered “unclassifiable,” because the available information is insufficient to make a determination; and
• EPA has expanded the boundaries of a Pennsylvania area that was previously found to be noncompliant.
Areas in violation include Southern Los Angeles County and the cities of Chicago, IL; Cleveland, OH; Muncie, IN; and Tampa, FL.
|EPA monitors fine particle emissions on a 24-hour and annual basis to determine compliance with air-quality standards.|
In all, the tally from EPA’s Lead NAAQX Final Nonattainment Designations lists 21 areas and parts of 22 counties across 15 states and Puerto Rico in violation of the federal health standard.
Determinations on the “unclassifiable” areas are expected once additional information is available.
Tougher Laws & Monitoring
In October 2008, EPA strengthened the nation’s air-quality standards for lead 10-fold, to 0.15 micrograms of lead per cubic meter of air. The agency also finalized requirements for new monitors to be located near large sources of lead emissions.
EPA’s pass/fail particulate matter designation system is based on averaging fine particle (PM2.5) concentrations both annually and on a 24-hour basis.
In this case, monitoring was conducted in two rounds. The first was completed in November 2010, and those results were released at that time. The announcement this week followed the second round and final results.
Areas that failed to meet the standards must develop plans within 18 months and implement them within five years to comply.
Lead Concentrations Decline
National average concentrations of lead in the air have dropped 93 percent nationwide since 1980, largely due to the phase-out of lead in gasoline, EPA reports. Lead in the air comes from a variety of sources, including smelters, iron and steel foundries, and piston-engine aircraft operating on leaded aviation gasoline.
Lead emitted into the air can be inhaled or, after it settles, ingested. Ingestion is the main route of human exposure. Children are most susceptible because they are more likely to ingest lead, and their bodies are developing rapidly. There is no known safe level of lead in the body, EPA reports.