An Assessment of Factors Associated with Increased Blood Lead Levels (BLL) Among Workers in the State of California Open Access

Stevens, Haley Elizabeth (2015)

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Background: Elevated blood lead levels (BLL) can cause a multitude of adverse health effects. Lead use has dramatically been reduced in the past 50 years, however Americans are still occupationally exposed in many industries. NIOSH currently conducts an adult blood lead surveillance program (ABLES) in most US states for those with higher exposure.

Methods: The ABLES database for California from 2003-2013 was used for this analysis to evaluate which demographic factors are associated with high BLL's among workers in California, as well as whether there are factors associated with significant trend changes in BLLs. Multiple linear regression was used to model BLL over time within 12 industries while controlling for age, sex, and Hispanic ethnicity.

Results: There were 508 workers with BLLs above 25 µg/dl, and 58 with levels above 40 µg/dL, indicating a small proportion of workers in California have levels associated with high risk of adverse effects. In California, there was a mean of 9.4 µg/dL among all industries and a downward trend in BLLs over time with a 9% decrease annually. Although BLLs have been decreasing and a majority are relatively low, there may still be adverse health effects associated with low level exposures. Additionally, there are some industries which show slower rates of decrease in BLL levels. Workers in firing ranges actually had increasing BLLs, at 0.5% per year, and also had the highest average BLLs among all industries (15.4 µg/dL). Secondary smelting had the second highest average (15.1 µg/dL) with a low annual decrease of 2.8%. Though copper foundries had a lower mean BLL (10.7 µg/dL), the industry barely saw decreases between 2003 and 2013 with an annual decrease of only 1% per year.

Conclusion: Occupational related BLLs are on average below elevated levels (<10 µg/dL) and decreasing over time in California, however, there are industries with significantly higher mean BLLs than the overall average and are not decreasing with a similar rate. It will be important to continue lowering BLLs in California overall as well as put specific focus on lowering BLLs within those industries with higher mean BLLs and low rates of decrease.

Table of Contents

Background 1-2

Methods 3-4

Results 5-6

Discussion 7-9

References 10-11

Tables 12-14

Figure 15-17

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