American Journal of Industrial Medicine 21:199-208 (1992)

Occupational Lead Exposure in Los Angeles County: An Occupational Risk Surveillance Strategy Paul J. Papanek, Jr., MD, MPH, Carolyn E. Ward, MPH, Kathleen M. Gilbert, MPH, and Stephen A. Frangos, MD, MPH

To better understand occupational lead exposures in Los Angeles County, we undertook a questionnaire survey of lead-using industrial facilities not previously identified by county health department staff. Previously our staff had identified 112 lead-using companies with approximately 2,000 lead-exposed workers countywide. For this survey, we developed a database of 1,353 possible lead-using industrial facilities from several sources, including community “right-to-know” databases, air pollution or sewer permit records, or other environmental databases. A questionnaire interview was completed with 1,001 (81%) of these companies, yielding 178 previously unidentified facilities employing 7,734 workers with potentially significant occupational lead exposures. Compliance with the OSHA lead standard was often poor in these facilities, particularly for workplaces with 20 or fewer employees. Devoting more public health resources to targeted identification of such industrial facilities and to educational outreach would likely help control occupational lead exposure. Key words: lead exposure, lead poisoning, hazard assessment, community “right-to-know,” OSHA, lead standard, occupational risk

INTRODUCTION

Occupational lead poisoning continues to be an important problem in the United States, affecting tens of thousands of workers [Landrigan, 1990; Rudolph et al., 19901. The best known effects of lead poisoning-anemia, colic, peripheral neuropathy and nephropathy-tend to occur at blood lead levels about 40-60 kg/dl [Goldman, 19871. Various subclinical and other toxic effects from lead exposure have also been demonstrated or strongly suggested at blood lead levels below legally permissible levels [Landrigan, 1989, 19901. In California, regulation of occupational lead exposure falls primarily under the jurisdiction of the California Occupational Safety and Health Administration (CalOSHA). The California and federal occupational lead standards are essentially identical and require all facilities in which significant occupational lead exposure might

Toxics Epidemiology Program, LOFAngeles County Department of Health Services, Los Angeles, CA. Address reprint requests to Dr. Paul J . Papanek. Jr., Toxics Epidemiology Program, Los Angeles County Department of Health Services, Room 607, 2615 S. Grand Ave., Los Angeles, CA 90007. Accepted for publication May 28. 1991,

0 1992 Wiley-Liss, Inc.

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occur to measure air lead levels in the facility and to inform employees that they are working with lead [California Code of Regulations; Code of Federal Regulations]. If the concentration of lead in the air exceeds the action level (AL) of 30 pg/m3 as an 8-hr time weighted average (TWA), the lead standard requires periodic air sampling and blood lead analyses, together with annual medical exams and health and safety training for exposed workers. At air lead levels exceeding the permissible exposure level (PEL) of 50 pg/m3, respiratory protection, work clothing, and shower facilities become compulsory. The Medical Removal Protection (MRP) provision of the lead standard requires reassignment to a work area with air lead levels below the AL, without loss of benefits, for any employee with a blood level of >60 pg/dl or the average of up to three consecutive tests over 6 months exceeding 50 pg/dl [Rempel, 19891. Recent data suggest that at a great many industrial sites, compliance with the OSHA lead standard is far from ideal. Data derived from OSHA compliance inspections from 1979 to 1985 have been used to identify industries with airborne lead concentrations frequently in excess of 50 pg/m3, such as battery manufacturers, secondary lead smelters, pigment manufacturers, and brassibronze foundries [Froines et a]. , 19901. In the radiator repair industry, workers are significantly exposed to lead fume from molten lead solder and to lead oxide dusts from grinding and wire brushing radiator joints [Goldman et al., 1987; Lussenhop et al., 19891. In California, radiator repair workers are among the least monitored of lead-exposed workers: fewer than one percent appear to receive routine blood lead testing [Rudolph et al., 19901. Beginning January 1 , 1987, the state of California required all state licensed medical laboratories to report blood lead levels exceeding 25 pg/dl to the California Department of Health Services (CDHS) and to the local health department within 72 hr of analysis [California Health and Safety Code, 19861. In its first year of operation, 1977, the California Lead Registry recorded 3,077 reports on elevated blood lead levels for 1,293 adults. In the vast majority of these adult cases, the lead exposures were occupational. California adults with elevated blood lead levels tended to be male (91%), residents of Los Angeles County (81%, falling to 57% in 1989), and disproportionately Hispanic surnamed (44%) [CDHS, unpublished data, 1988, 1989; Maizlish et al., 19901. In 1989, approximately 0.1% of the 4,364 elevated blood lead levels reported in Los Angeles County exceeded 80 pg/mdl, 3% exceeded 50 pg/dl, and 11% exceeded 40 pg/dl. Through follow-up of these reports of elevated blood lead levels in Los Angeles County, our staff became aware of 112 industrial facilities in the County that used lead in a manner likely to cause significant exposure for approximately 2,000 workers. Despite this substantial body of surveillance data, we believed that the actual number of lead exposed workers was considerably greater. It has been estimated that fewer than 3% of lead-exposed workers in California receive the benefit of periodic air or blood lead testing [Rudolph et al., 19901. Thus, those industrial facilities or workers already reported to the California state or local health departments probably represent only a fraction of actual lead-exposed workers in the state. In 1988, in order to better understand the extent of blood lead reporting and patterns of compliance with the OSHA lead standard, particularly in smaller workplaces, the Los Angeles County Department of Health Services initiated a survey of lead-using companies in the county. This paper reports the methodology we used to identify industrial lead-using facilities in the county and describes patterns of com-

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pliance with some specific provisions of the OSHA lead standard in those facilities. We believe that this project represents a novel and promising use of community “right-to-know’’ databases of hazardous materials for purposes of occupational risk surveillance. MATERIALS AND METHODS Study Population

A single database of 1,353 potential lead-using companies located in Los Angeles County was created from seven sources, as follows: (1) Dun’s Electronic Yellow Pages was searched for the keywords “lead,” “smelt,” “battery,” “radiator,” and “brass”; (2) the Dun and Bradstreet Business Directory for 1988 was searched for about 100 four-digit Standard Industrial Classification (SIC) codes likely to be associated with lead use (Table 111 lists the SIC codes, grouped into two-digit categories); ( 3 ) the Los Angeles County Department of Health Services maintains a database of industrial facilities licensed as hazardous waste generators; this database was searched by these same SIC codes; (4) the Los Angeles City Fire Department maintains a database of industrial facilities which have submitted inventories of hazardous materials stored on site, pursuant to California state reporting requirements essentially equivalent to the reporting requirements of Title I11 of the federal Superfund Amendments and Reauthorization Act of 1988, also known as the community “right-to-know’’ act; this database was searched for the keyword “lead”; (5) a database maintained by the Los Angeles County Sanitation Districts was examined for listings of companies required to monitor their waste water discharges for lead; (6) a database maintained by the Los Angeles City Department of Public Works, Bureau of Sanitation, was examined for listings of companies required to monitor their waste water discharges for lead; and (7) a database maintained by the South Coast Air Quality Management District (AQMD), the air pollution regulatory agency for the Los Angeles basin, was examined for listings of companies with permits to discharge lead emissions to ambient air. Study Survey

We made at least three attempts to contact each facility in the database by phone, in order to interview a facility representative using a standardized questionnaire. Respondents were informed the results of the survey would be kept confidential and that no answers would be used for enforcement or punitive purposes. If a telephone interview could not be completed, typically because the facility had no phone listing or because the company spokesperson refused to discuss such information over the phone, a copy of the questionnaire was mailed to the facility. Interviews were conducted by seven trained interviewers over a 2-year period. The survey included questions about the size of the industrial facility, number of workers, type of industrial process involving lead use, and the quantity of lead used at any one time at the facility and over the course of a year. Respondents who indicated that potentially significant occupational lead exposures were occurring at the facility were also asked about their awareness of and compliance with various provisions of the OSHA lead standard, including air monitoring, frequency of medical surveillance and worker training, and routine hygiene practices. On the basis of the interview, we categorized each company as a non-lead user,

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a lead user with minimal risk of employee exposure to lead, or a lead user with potentially significant employee exposure to lead. We classified lead use as causing ‘‘potentially significant employee exposure” if the respondent described industrial processes on site involving heating, melting, grinding, welding, or spraying more than 5 lb/year of lead. For nearly all of these facilities, lead use exceeded 100 lb/year. Facilities whose only lead use consisted of soldering electronic components with small quantities of lead-containing solder were not classified as posing a significant risk of employee lead exposure. Employers who were unaware of the requirements of the OSHA lead standard or who asked for more information were sent a copy of the OSHA lead standard and information about private consultants or other available industrial hygiene resources. These companies were interviewed again after 4 weeks, and their baseline data were updated. The final data set reflects information available at the time of this second interview.

RESULTS

Of the 1,353 companies identified in the baseline database, 54 had previously been identified by our staff and were therefore dropped from the survey. A further 65 facilities were dropped because they had gone out of business or had an SIC code indicating that they were distributors of lead-containing products but did not otherwise use or process lead on site. Of the remaining 1,234 facilities, 1,003 (81%) were successfully interviewed, while 23 1 (19%) failed to respond to repeated attempts at contact. Of the completed interviews, 88% were conducted by phone and 12% were conducted by mail. The survey identified 178 companies (18%) that reported using lead in a manner likely to cause significant lead exposure for 7,734 workers. As described above, our staff had previously been aware of 112 additional industrial facilities using lead in a manner likely to cause significant lead exposure for about 2,000 employees. Thus, this outreach effort increased our list of probable lead-using facilities from 112 to a total of 290, and our estimate of workers with potentially significant lead exposure from 2,000 to nearly 10,000. These workers were described as spending much of their time in areas in which lead-containing material was melted, ground down, abraded, or otherwise finely divided or aerosolized. An additional 135 facilities (13%) reported using lead in a way that would be unlikely to cause significant exposure to employees. Table I lists the number of lead-using facilities identified by each database source. For two sources, the Los Angeles City Fire Department’s hazardous materials inventories and the South Coast Air Quality Management District’s database of permit holders, more than half of the facilities listed in the initial database reported potentially significant employee lead exposures. Table I1 describes the 178 facilities with potentially significant employee lead exposures and the extent of their compliance with some of the provisions of the OSHA lead standard, tabulated by reported air lead concentration. Respondents at 110 (62%) of these facilities either could not recall ever having had an air lead measurement taken on site or were unable to provide reasonable evidence that they had done so. Of note, for the 135 lead-using companies we characterized as posing

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TABLE 1. Database Sources Identifying Lead-Using Companies

Source

-

_____

Identifiers ~~~

Lead users with Lead No. of potentially signifusers/ No facilities icant exposures no industrial Unsuc- initially (8of identified) significant lead cessful identified facilities) exuosures use contact bv source

~

Electronic Yellow Pages Dun & Bradstreet Business Directory LA County Hazardous Waste Permits LA City Fire ("Right-to-know" Inventories) LA County Sanitation LA City Sanitation South Coast AQMD (air poll. agency)

Type/description of business SIC codes

31 (19%)

68

51

161

36 (13%)

164

68

284

SIC codes

31 (13%)

121

78

239

Lead reported to be used or stored on site Sewer permit to discharge lead Sewer permit to discharge lead Air permit to discharge lead

46 (53%)

1s

18

87

Totals

31 (15%)

31

90

53

205

20 (5%)

68

244

85

417

23 (66%)

1

4

7

35

178 (13%)

I35

-

-

-

690

350

1,353

TABLE 11. Characteristics of Lead-Using Companies by Air Lead Level (N = 178)

No. of facilities Workers exposed to lead Years in business at site (median) Highest PbB" at facility (median) Workers on MRPb in past year Lead standard compliance (% of companies) % sampling air lead within past 6 mos % ever measured PbB" levels % with routine PbB" monitoring % with written compliance program % aware of M R P ~requirements % providing change of clothing % providing showers 8 providing annual employee training

Low (

Occupational lead exposure in Los Angeles County: an occupational risk surveillance strategy.

To better understand occupational lead exposures in Los Angeles County, we undertook a questionnaire survey of lead-using industrial facilities not pr...
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