Lead Hazards Around Us

Submitted by: Hyun-Jeong Lee, Ph.D., Assistant Professor/Housing Specialist

Laquatra, J., Pierce, M., & Hammer, T. October 2007. “Lead in Christmas Tree.” Proceedings of Housing Education and Research Association Annual Conference, 117-122.

Introduction

Lead poisoning has been and a threat to human health for more than 100 years. During the last couple of decades, the median blood lead concentration in U.S. children has dramatically declined mainly due to removal of lead from gasoline (Rogan & Ware, 2003). Also, public awareness of the lead poisoning hazard was increased. However, lead hazard of homes that were built before 1978 still exist and consumer products that contain lead have been continuously found and recalled. Refer to the U.S. Consumer Product Safety Commission (CPSC) website for the list of items that were recently recalled (http://www.cpsc.gov/recentrecalls.html).

In the past, lead was used to make paint for easier application which was banned in the United States in 1978. Laquatra, Pierce and Hammer (2007), a team of researchers at the Cornell University, state that lead is also used to stabilize polyvinyl chloride (better-known as PVC), coating on electrical conductors. Recently, consumer questions on lead poisoning hazard of Christmas lights were increased. In response to the consumer concerns, Laquatra, et al. purchased three different Christmas lights and conducted preliminary lead tests: a rope lighting; a star light set; and a flame tip light set. Fortunately, they reported that there was no lead at or above “level of concern” found on the products. However, the researchers express their concerns on small amount of lead containment they found.

Main Ideas

“Level of Concern”

To discuss the regulatory definition of “level of concern,” we need to consider two types of “level”: level of lead containments in products, and level of lead concentration in human blood. Regarding the level of lead containment in products, the Department of Housing and Urban Development (HUD) defines lead-based paint is paint or other surface coatings that contain lead equal to or exceeding 1.0 milligrams per square centimeter (mg/cm2) or 0.5 percent by weight (equivalent to 5,000 parts per million or ppm) while CPSC defines “lead containing paint” as paint or similar surface coating materials in which the lead content exceeds 0.06 percent by weight (16 C.F.R. Part 1303) (equivalent to 600 ppm) (CPSC, 2007). In terms of the level of lead concentration on human blood, CDC and the World Health Organization (WHO) defined blood lead level (BLL) at or above 10 microgram per one deciliter (10μg/dL) as a “level of concern.”

Lead Poisoning on Brain Development

As discussed in previous article (RNYCU, March 2007, Hyun-Jeong Lee), lead poisoning have been proven to influence development of brain, nervous system, and kidney. Also, it slows down physical growth, causes behavior and learning problems, and even death (U.S. Environmental Protection Agency (EPA), 2007; Centers for Disease Control and Prevention (CDC), 1991).

For last few decades, many research studies were conducted to explore the influence of children’s blood lead concentration on their IQs including one by Canfield, Henderson, Jr., Cory-Slechta, Cox, Jusko, Lanphear (2003). Results of the studies indicate that blood lead concentration showed significant negative impacts on IQs of children whose BLLs were even below the “level of concern.”

Recently, a research team at the Cornell University that was lead by Canfield conducted additional study on the influence of blood lead concentration on children’s IQs and confirmed that “blood level played a significant role in predicting nonverbal IQ scores” of children with BLLs below 10μg/dL (Lang, 2007). These findings imply that even a low-level exposure to lead can result in serious problems on children’s brain development.

As we see from the findings of the lead testing of Christmas lights, lead above the current “level of concern” found on the products. However, there are questions still remains: “How low is low enough? (Rogan & Ware, 2003)” Does “below the level of concern” mean there is no need to concern? Some remaining concerns may be associated with children’s continuous and direct exposure to the low-level lead. It is well-known that children are more easily exposed to the lead hazard because of their hand-to-mouth behavior: They put things in their mouth and/or often forget to wash their hands before eating. Christmas decorations could be one of the most exciting family activities of the year. Children may help with the decoration and have snacks without washing their hands after touching items that are of concern).

Product Lead Test

There are some consumer lead testing kits available at hardware stores or on Internet sites. CPSC staff evaluated two types of consumer lead testing kits and concluded that those kits were not reliable (CPSC, 2007). They reported that those testing kits sometimes showed either false negative (results showing that the product does not contain lead when it does) or false positive (result showing that the product contains lead when it does not) and recommended consumers not rely on the testing kits. They suggested that laboratory testing was the only reliable lead testing of consumer products. However, this laboratory testing is more expensive  and consumers may not be able to afford to test their children’s toys or households items. So, for now, the only way consumers could be informed of the lead hazards is through media including website of CPSC (http://www.cpsc.gov).

Suggestions for Lead Poisoning Prevention

Keep your eyes on the CPSC websites for consumer products recalled because of the lead hazard issues. Wash yourself and your babies often to reduce absorbance of lead. Promote healthy behaviors in children.   Wash their hands every time they eat and teach them not to put toys or other non-food items in their mouths. Consult your doctor for blood lead level screening test of your children age 72 months or younger especially if you are living in a house built before 1978. Regularly clean dust from your floors, window frames, window sills, and other surface weekly. If you think your home has lead problem, it is recommended you  contact professionals for inspection and necessary abatement. Make sure your children eat good foods to prevent lead poisoning. Children who eat nutritious foods with high iron and calcium (e.g., spinach and dairy products) tend to absorb less lead to their body (EPA, 2007).

Implications for Extension Programs

Outreach education activities of childhood lead poisoning prevention need to be emphasized to reach underserved populations, including low-income families who may reside in poor quality old houses and minorities speaking foreign languages. Media approaches using TV or radio may be one of the ways to effectively reach the under-served low-literacy population.           

Further Information

Please visit EPA and CDC websites below for more up-to-date information on children lead poisoning prevention:

References

Canfield, R. L., Henderson, Jr., C. R., Cory-Slechta, D. A., Cox, C., Jusko, T. A., & Lanphear, B. P. (2003). Intellectual impairment in children with blood lead concentrations below 10 μg per deciliter. The New England Journal of Medicine, 348(16), 1517-1526.

Centers for Disease Control and Prevention. (1991). A statement by the centers for disease control and prevention. Retrieved December 10, 2007, from Lang, S. (2007, November 20).

CU study: Lead levels even well below U.S. standard may affect brain function in children. Cornell Chronicle. Retrieved December 10, 2007

Rogan, W. J., & Ware, J. H. (2003). Exposure to lead in Children – How low is enough? The New England Journal of Medicine, 348(16), 1515-1516.
U.S. Consumer Product Safety Commission Staff. (2007, October). CSPC staff report: Evaluation of lead test kits. U.S. Consumer Product Safety Commission. Retrieved December 10, 2007

U.S. Environmental Protection Agency. (2007). Lead in paint, dust, and soil. Retrieved December 10, 2007