Lead exposure in radiator repair workers: a survey of Washington State radiator repair shops and review of occupational lead exposure registry data

Blood lead level risk factors and reference value derivation in a cross-sectional study of potentially lead-exposed workers in Iran

OBJECTIVES

This exploratory investigation aimed to measure blood lead levels and associated risk factors in exposed workers in Iran, and to derive appropriate reference values for blood lead in this population as a means of epidemiological comparison.

DESIGN

Cross-sectional.

SETTING

Manufacturing plants with potential lead exposure in Southern Khorasan Province, Iran.

PARTICIPANTS

The study included 630 workers, selected through stratified random sampling.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary measures in this exploratory investigation were venous blood lead concentration (BLC) and associated risk factors of age, gender, work experience, cigarette smoking and history of opium use. The secondary measures were symptoms associated with lead toxicity. Data analyses were conducted using Student's t-test, Mann-Whitney U test, one-way analysis of variance, Kruskal-Wallis test, Spearman correlation coefficient and regression analysis.

RESULTS

Mean and median BLCs were 6.5±8.1 μg/dL and 3.9 μg/dL (IQR: 2.9-5.8), respectively. Of the subjects, 85 (13.5%) had BLC ≥10 μg/dL. The derived reference BLC value in this study was 30 μg/dL for men and 14 μg/dL for women. Increasing work experience and age were associated with BLC >10 μg/dL. Radiator manufacturers were up to 12.9 times (95% CI 4.6 to 35, p<0.005) more likely than painters to have BLC >10 μg/dL. Most subjects reported multiple symptoms.

CONCLUSIONS

The mean BLC was above the maximum recommended concentration. There was a significant relationship between higher BLC and age or working in a printing factory or radiator manufacturing. These findings can direct efforts towards reducing occupational lead exposure.

Elevated blood lead levels in adults-Missouri, 2013

BACKGROUND

Over 90% of adults with elevated blood lead levels (BLLs) in the United States are exposed occupationally. Missouri historically has been among the states with the highest prevalence rates of elevated BLLs. We characterized cases of elevated BLLs among Missouri adults to target preventive interventions.

METHODS

We reviewed 2013 data on Missouri residents ≥16 years from the Missouri Adult Blood Lead Epidemiology and Surveillance system and analyzed characteristics of those with elevated BLLs. We used the contemporaneous CDC definition of elevated BLL as ≥10 μg/dL.

RESULTS

Of the 15 123 residents with a BLL in 2013 (median: 1.5 μg/dL, range: 0-151 μg/dL), 3145 (21%) had BLLs ≥10 μg/dL. Occupational exposures accounted for the majority of residents (n = 3099, 98%) with elevated BLLs, mostly in battery manufacturing (n = 1373, 44%) and lead mining (n = 821, 26%) industries.

CONCLUSIONS

Our findings highlight the need for focused interventions targeting battery manufacturing and lead mining, the high-risk industries, to further reduce overexposures to lead.

Assessment of lead exposure among automobile technicians in Khyber Pakhtunkhwa, Pakistan

Exposure to Pb among automobile technicians in selected towns of Khyber Pakhtunkhwa Province, Pakistan, was studied using a questionnaire, biological sampling (blood, hair, nails), and analysis of Pb biomonitoring data across various subgroups of occupation, age, and years of exposure. The study population included exposed automobile technicians (n=50) and a control group (n=50). The automobile technicians were further stratified into 4 groups: mechanics, auto-body technicians, electricians, and painters. Mean Pb levels in biological samples of the automobile technicians were significantly higher than in the control group (P<0.01). The Pb concentrations (mean±standard deviation) in whole blood, hair, and nails of automobile technicians were 65.3±41.9μgdL^-1, 23.6±11.2mgkg^-1 and 29.7±14.5mgkg^-1, respectively, whereas concentrations in the control group were 21.7±17.6μgdL^-1, 4.8±3.4mgkg^-1 and 7.2±3.9mgkg^-1. Fifty two percent of the automobile technicians had blood levels >50μgdL^-1, but only 14% of the control group exceeded this level. Considering that Pb blood levels of 50μgdL^-1 exceed maximum concentrations recommended by leading public health organizations, appropriate measures should be taken to protect the welfare of the exposed automobile technicians and their families.

Blood lead levels of Korean lead workers in 2003-2011

OBJECTIVES

This study aimed to document the trend in blood lead levels in Korean lead workers from 2003 until 2011 and blood lead levels within each of the main industries.

METHODS

Nine years (2003-2011) of blood lead level data measured during a special health examination of Korean lead workers and collected by the Korea Occupational Safety and Health Agency were analyzed. Blood lead levels were determined by year, and a geometric mean (GM) was calculated for each industry division.

RESULTS

The overall GM blood lead level for all years combined (n = 365,331) was 4.35 μg/dL. The GM blood lead level decreased from 5.89 μg/dL in 2003 to 3.53 μg/dL in 2011. The proportion of the results ≥30 μg/dL decreased from 4.3% in 2003 to 0.8% in 2011. In the "Manufacture of Electrical Equipment" division, the GM blood lead level was 7.80 μg/dL, which was the highest among the industry divisions. The GM blood lead levels were 7.35 μg/dL and 6.77 μg/dL in the "Manufacturers of Rubber and Plastic Products" and the "Manufacture of Basic Metal Products" division, respectively.

CONCLUSIONS

The blood lead levels in Korean lead workers decreased from 2003 to 2011 and were similar to those in the US and UK. Moreover, workers in industries conventionally considered to have a high risk of lead exposure also tended to have relatively high blood lead levels compared to those in other industries.

Occupational lead exposure: blood lead levels of apprentices in Bursa, Turkey

The aim of this cross-sectional study was to compare the blood lead levels of apprentices working in lead-related industries with those of non-apprentice controls and to evaluate the influence of such occupational exposure. The study was conducted between October 2004 and June 2005 in Bursa, Turkey. Subjects included 231 apprentices and 252 male controls, age ranging from 14-19 yr old. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze blood lead levels. The overall mean blood lead level was 3.62 microg/dl (95% CI 3.39-3.85), the apprentice mean was 4.99 microg/dl (95% CI 4.60-5.38), and the control group mean was 2.37 microg/dl (95% CI 2.22-2.51). The blood lead level of apprentices was significantly higher than that of controls (p<0.05). Results show that occupational exposure increases the blood lead levels of apprentices, although the impact on their immediate health is low. Measurement of blood lead levels of apprentices should be taken periodically, and a regular medical surveillance program should be established.

Characteristics of US workers whose blood lead levels trigger the medical removal protection provision, and conformity with biological monitoring requirements, 2003-2005

BACKGROUND

Workers with blood lead levels (BLL) > or =60 microg/dl (50 microg/dl for construction workers) or with three or more consecutive BLLs over at least 6 months that average 50 microg/dl or greater are required to be removed from work involving lead exposure that exceeds the OSHA action level. This study estimates the proportion of workers with BLLs that trigger the medical removal provision by industry sector, and examines whether workers received appropriate follow-up blood lead testing.

METHODS

Three years (2003-2005) of data from the Adult Blood Lead Epidemiology and Surveillance program were analyzed to identify those industries with a high percentage of workers with BLLs that trigger the medical removal provision. Adjusted rate ratios (RR) of adults with such BLLs were estimated by industry sector compared to the battery manufacturing industry using Poisson regression models.

RESULTS

Out of 13,724 adults with BLLs > or =25 microg/dl, a total of 533 adults had BLLs that triggered the medical removal provision. RRs of adults with BLLs triggering medical removal were highest for "painting and wall covering contractors" (RR = 22.1) followed by "highway, street and bridge construction" (RR = 14.7), "amusement, gambling, and recreation" (RR = 11.4), and "glass product manufacturing" (RR = 10.1). Overall, 29% of adults with BLLs triggering medical removal received appropriate follow-up blood lead tests and met the eligibility to return to lead work.

CONCLUSIONS

These findings suggest that additional efforts are needed to prevent occupational overexposure to lead in adults, and to ensure proper medical management of those workers who meet medical removal criteria.

Survey of current lead use, handling, hygiene, and contaminant controls among New Jersey industries

In 2003, a chemical handling and use survey was mailed to New Jersey employers identified as currently using lead in their industrial processes. This survey was used to ascertain characteristics about lead use, handling, and protection of employees during manufacturing operations. The survey included a diverse group of current lead users with a total lead use range from less than 1 pound to more than 63 million pounds of lead per year. The survey allowed for a comprehensive characterization of hazards and protective measures associated with this metal, still commonly used in many products and industrial processes. Forty-five surveys were returned by companies that are listed in the New Jersey Adult Blood Lead Registry, which is part of the New Jersey Adult Blood Lead Epidemiology and Surveillance (ABLES) program. This program records and investigates cases of adults with greater than 25 mu g/dL of lead in their blood; most cases are related to occupational exposures. This survey found that greater than 25% of these surveyed companies with significant potential for lead exposure did not employ commonly used and basic industrial hygiene practices. In addition, the survey found that 24% of these companies had not conducted air sampling within the last 3 years. Air sampling is the primary trigger for compliance with the Occupational Safety and Health Administration (OSHA) general industry lead standard. Only 17% of the companies have ever been cited for a violation of the OSHA lead standard, and only 46% of these companies have ever had an OSHA inspection. State-based surveillance can be a useful tool for OSHA enforcement activities. Elevated blood lead values in adults should be considered as a trigger for required compliance with an OSHA general industry lead standard.