Lead

Background

Lead is a heavy metal found naturally in the environment as well as some manufactured products (lead-acid batteries, lead-based paints, leaded glass, solder, chemicals, some imported children’s toys and jewelry, etc.) and older water distribution systems (corrosion of older fixtures, pipes, brass fittings, and lead solders to connect the pipes). Lead is a persistent chemical that accumulates in soils, aquatic systems and sediments, and in some plants, animals, and other organisms. Used for many years as an additive to motor vehicle fuel (tetraethyl lead), the small particles of lead and lead compounds have deposited along roadways binding chiefly to the organic materials in soils. When the soil or sediment is stirred up, lead particles can be re-suspended in the atmosphere.

In October 2008, the Environmental Protection Agency (EPA) strengthened the national ambient air quality standards (NAAQS) for lead to increase protection of public health and the environment. The ambient air lead standards—both the primary (health-based) and secondary (environment-based) standards—have been revised to 0.15µg/m3 (micrograms per cubic meter of air). The previous NAAQS issued by the EPA in 1978 were ten times higher (1.5µg/m3). Standards are based on the concentration of lead in total suspended particles (TSP). To meet the new standard, a rolling three-month average of measured lead concentrations at a particular sampling site may not exceed 0.15µg/m3 evaluated over a three-year period. This means that if any three-month average is 0.15µg/m3 or higher, the site would be in violation of the standard.

Since 1990, more than 6,000 studies on lead’s adverse effects to human health and the environment have been published. Evidence from many of these studies show that serious health effects to children may occur even when blood level levels are below 10 micrograms lead per deciliter of blood. Examples of such effects include a loss of IQ, behavioral problems, learning disabilities, memory and attention problems that can affect lifetime education and achievement. Infants and small children (age 6 or younger) are particularly susceptible to lead poisoning. Lead can enter their rapidly developing bodies from the air they breathe in, from the soil and paint chips containing lead they may ingest, from the toys with lead-based paints that go into their mouths, or from the water they drink. Adults may also experience adverse health effects from lead exposure—increased blood pressure, cardiovascular disease, decreased kidney function, and impaired immune systems.

Based on 2008 emission reports provided by Utah industrial sources, Kennecott Copper Corporation’s smelter, refinery, power plant, and tailings impoundment near Magna and its mine and concentrator near Copperton represent the state’s largest sources of lead. Smaller sources in the state include general aviation aircraft powered by piston-engines that generally require leaded-fuels, manufacturing sources, and industrial, commercial, and utility boilers used by power plants and hot mix plants. These point and area sources control lead emissions the same way they control fugitive and stack particulate emissions—bag houses, electrostatic precipitators, wetting down areas where fugitive dust emissions are visible, etc.

For more information about lead-based paint in pre-1978 target housing or child-occupied facilities, visit the Lead-Based Paint Program.

Air Monitoring for Lead

From 1982 through 2005, the Division of Air Quality (DAQ) monitored for lead in various cities along the Wasatch Front. No violations of the former NAAQS were ever measured at any of these sites where lead concentrations were averaged over calendar quarters. The 2008 revised lead NAAQS required DAQ to monitor again for lead in the ambient air. In January 2010, monitoring was restarted near Kennecott’s smelter and refinery in Magna. Beginning January 2011, air monitoring for lead must commence in Copperton near Kennecott’s concentrator, at DAQ’s Hawthorne monitoring station in Salt Lake City (1675 South 600 East) and at the Salt Lake International Airport. Ambient air monitoring for lead at each of these sites must be conducted for at least three years. Due to the lack of current monitoring data, all areas of the state are currently designated unclassifiable for lead.

Lead Trends

Since 1980, lead concentrations have decreased dramatically both nationally and locally. A gradual phase-out of leaded gasoline for motor vehicles in the 1970s and 1980s accounts for the sharp declines.

Not surprising, lead levels tend to be highest near the state’s largest lead sources. This explains why DAQ is required to monitor for the pollutant in Magna and Copperton. The persistent nature of the toxic heavy metal requires that lead monitoring also be conducted in urban areas to characterize lead background levels.

View a trend plot of average annual lead concentrations (41 KB) measured at three monitoring stations in Salt Lake County where the airborne pollutant was sampled every sixth day over a ten-years or longer.

The listed stations and addresses are:

  • The former Air Monitoring Center (AMC) at 261 West 500 South, SLC
  • Salt Lake Valley Health Department (SLVHD) at 200 East 610 South, SLC
  • Magna (MG) at 2935 South 8560 West, Magna.