Lead exposure causes numerous health effects including lowered IQ, shortened attention span, decreased coordination, learning disabilities, and neurological development problems. These adverse affects can occur below the blood lead level reference value of 5 micrograms/deciliter set by the Centers for Disease Control and Prevention (Canfield, Henderson, Cory-Slechta, Cox, Jusko & Lanphear, 2003). This is the number which triggers doctors and state agencies to step in and help identify lead sources to reduce blood lead levels in children.
Historically, lead has been found in a number of consumer products, such as paint, plumbing, and gasoline. This legacy lives on today in children’s toys, ceramics, vinyl products, and certain jewelry. The government continues to devote significant resources annually to remediate the long term impacts and presence of lead.
Our estimate of the costs associated with the full range of behavioral and cognitive effects of lead poisoning in Oregon is based on the methodology used by Landrigan et al. To account for the lifetime costs associated with lower earning potential caused by lead poisoning, Landrigan et al. used data on the relationship between the loss of IQ due to lead-related decreases in IQ and expected lifetime earnings. This method assigns to a birth cohort an average amount of money they would be expected to earn in a lifetime. This method is based on lost income and does not take account of direct health care costs for screening and treatment, or indirect costs such as special education and juvenile justice services.
Following Landrigan, we assume an EAF of 100%, as all cases of lead poisoning are reasonably assumed to be of environmental origin.
The annual lost lifetime earnings due to lead poisoning are calculated as follows:
(mean blood lead level of 1-5 year old child) * (loss of IQ points per unit blood lead) * (loss of lifetime earning per IQ point) * (number of boys and girls, respectively) * (EAF of 100%)
We used the CDC’s latest National Health and Nutrition Examination Survey (NHANES) data on average blood lead levels of 1.9 µg/dL for 1- to 5 year-olds (Schwemberger et al., 2005). There are no Oregon specific data on blood lead levels available.
Based on a study by Canfield et al. (2003), we assumed a blood lead level of 1µg/dL translates into a loss of 0.46 IQ points. This estimates that a blood lead level of 1.9 µg/dL results in a loss of 0.874 IQ points (1.9 * 0.46).
According to Landrigan et al.’s methodology, we assumed that a loss of one IQ point equals the loss of 2.39% of lifetime earnings; therefore a loss of 0.874 IQ points equals a loss of 2.09% lifetime earnings.
The Bureau of Labor Statistics has determined that the expected lifetime earnings for 5 year old boys as $881,027 and for 5 year old girls as $519,631 in 1997 dollars (Bureau of Labor Statistics, 1999). These estimates adjusted are equivalent to $1,153,717 for boys and $680,464 for girls in 2007 dollars.
Oregon’s 2005 birth cohort consisted of 45,905 babies (Oregon DHS, 2005). Since Oregon does not track sex ratios of live births, we calculated the sex ratio of the 2005 birth cohort using 2000 U.S. Census data showing that Oregon’s population is 49.6% male and 50.4% female (U.S. Census Bureau, n.d.). Assuming that these same ratios are present at birth, the 2005 birth cohort consisted of 22,768 boys and 23,136 girls.
Our estimate of the annual lost lifetime earnings due to lead poisoning are based on the following assumptions:
- Current average blood lead level of 1-5 year olds in U.S. is the same as 1999-2002 data: 1.9mg/dL;
- Children in Oregon have average blood lead levels equivalent to national levels;
- Loss of 0.46 IQ points per 1 mg/dL blood lead;
- 2.39% loss of life time earning per IQ point;
- Lifetime earnings lost for boys $1,153,717 and for girls $680,464 (2007 dollars);
- Oregon’s 2005 birth cohort: 45,905;
- Oregon sex ratios: 49.6% boys, 50.4% girls resulting in 22,768 boys and 23,136 girls in born in 2005; and
- EAF = 100%
Costs in Oregon
Lost lifetime earnings for Oregon boys/girls:
=Expected lifetime income for boys/girls * number of boys/girls in Oregon 2005 birth cohort * 2.09% lifetime loss * EAFR 1.0
Lost lifetime earnings for Oregon boys: ($1,153,717) * (22,768) * (2.09%) * (EAF 1.0) = $549.0 million
Lost lifetime earnings for Oregon girls: ($680,464) * (23,136) * (2.09%) * (EAF 1.0) = $329.0 million
Lost lifetime earnings for Oregon boys and girls together:
=$549.0 million + $329.0 million = $878.0 million.
Lost lifetime earnings due to lead poisoning in Oregon are estimated at $878.0 million per year.
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