Occupational Blood Lead Survey -- Armenia, 1991 and 1993

The risk for lead exposure and lead poisoning is a persistent problem for some workers (1) and is an important issue in both industrialized and developing countries (2). In Armenia, where lead is used widely in industry (3), the Armenian Engineers and Scientists of America, Inc. (AESA), and the United Armenian Fund (UAF) * initiated a program in 1991 to use blood lead determinations to investigate lead exposures, identify industries and circumstances associated with lead hazards, and define specific jobs characterized by excessive exposures that increase the risk for lead poisoning of workers. In 1991, team investigators surveyed four factories that use lead; in 1993, one of the factories was resurveyed. Because the capacity of laboratories in Armenia to reliably determine blood lead levels (BLLs) is limited, blood specimens were transported to the United States for lead testing. This report presents the findings of both surveys and establishes the feasibility of sample collection at remote sites for transport to laboratories equipped and certified to process lead specimens.

The Armenian Institute of General Hygiene and Occupational Diseases in Yerevan selected four worksites for the initial survey in November 1991 based on factors including accessibility and operation. ** Two sites were printing plants that used cast lead type ("printing plant A" in Yerevan and "printing plant B" in Hoktemberian); one was a research laboratory that periodically used lead compounds in toxicologic experiments ("research institute" in Yerevan); and the fourth was a lead crystal factory that used red lead oxide in the manufacture of decorative glassware ("crystal factory" in Arzni). Participation in the survey was offered to all workers in jobs believed to be at high risk for lead exposure and to some administrators considered not to have substantial exposure. Of the workers who were present on the respective survey days, approximately 75% volunteered and permitted whole blood samples to be obtained. Because extremely high exposures were identified in the crystal factory in 1991, the factory was resurveyed in September 1993. For the 1991 survey, 34 workers at printing plant A participated; 17 at printing plant B; 10 at the research institute; and 38 at the crystal factory. For the 1993 follow-up survey at the crystal factory, 19 workers participated, including 10 from the 1991 survey.

Blood specimens from workers were collected by venipuncture into lead-free, evacuated tubes containing sodium heparin anticoagulant, stored at cool room temperature, and transported within 7 days to an Occupational Safety and Health Administration (OSHA)-approved laboratory in the United States for lead determination by atomic absorption spectrophotometry (4). Analyses were completed within 7 days of sample collection. Wipe samples of surface dust were collected onto lead-free castile soap wipes from 1-sq-ft areas of floors and machinery surfaces (at breathing-zone heights) and from the hands of workers, then were transported to the United States for lead determination by atomic absorption spectrophotometry (5). Routine external and internal quality-control measures were applied for blood and environmental analyses.

In 1991, of the 51 workers surveyed at the two printing plants, 50 had BLLs less than 25 ug/dL; none exceeded 40 ug/dL (Table_1).*** Among the 10 workers surveyed at the research institute, BLLs ranged from 2 ug/dL to 5 ug/dL. In both the 1991 and 1993 surveys at the glassworks, however, a substantial proportion of the 39 total specimens obtained from the production workers surveyed had elevated BLLs, and some were markedly elevated: 31 (79%) were greater than or equal to 25 ug/dL, 19 (49%) were greater than 40 ug/dL, and eight (21%) were greater than 65 ug/dL; among administrative and office workers, BLLs as high as 22 ug/dL were recorded.

A walk-through inspection of the crystal factory in 1993 identified sites characterized by poor housekeeping practices and conditions suggesting substantial airborne exposures.**** A total of 24 wipe samples were obtained to assay dust: 19 samples were from floors and machinery surfaces in working areas, two from an office hallway, and three from workers' hands (Table_2). All dust samples from processing areas were highly contaminated with lead (levels ranged from 3800 to 415,000 ug/sq ft); in comparison, guidelines for surface lead levels after residential lead abatement in the United States specify levels of 100 ug/sq ft for floors, 500 ug/sq ft for window sills, and 800 ug/sq ft for window wells (8). The highest values were detected in the lead oxide mixing area, where spillage of raw material was visible. Remedial measures were recommended to factory management.

Reported by: LA Saryan, PhD, Industrial Toxicology Laboratory, West Allis Memorial Hospital, Wisconsin. EA Babayan, MD, Institute of General Hygiene and Occupational Diseases, Republic of Armenia, Yerevan. L Amirian, Palo Alto, California. Div of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, CDC.

Editorial Note

Editorial Note: Controlling workplace lead exposure is essential in reducing the incidence of occupational disease caused by lead; monitoring of BLLs among workers is a necessary component of a comprehensive control strategy. In the United States, occupational lead exposure is regulated according to the provisions of the OSHA inorganic lead standard, which mandates periodic exposure assessment and blood lead monitoring for workers exposed above the action level (30 ug/m3) (7). Results of blood lead monitoring of workers are gathered by state agencies and compiled by CDC's National Institute for Occupational Safety and Health (NIOSH) (6).

Accurate blood lead analysis requires complex instrumentation and careful adherence to protocol; in many countries, the capacity of laboratories to reliably determine BLLs is limited. The findings in this report are the first to document reliable blood lead data reflecting occupational lead exposures in Armenia and establish the technical feasibility of sample collection at remote sites for transport to a laboratory appropriately equipped and certified to process the specimens. Although similar approaches may be applicable to the study of occupational lead exposures (and similar occupational health problems) in developing countries, economic constraints and other factors may limit the use of such approaches for routine surveillance.

Because of the small numbers of facilities and workers studied, voluntary participation, and the methods used for selection, the findings in this report are unlikely to be representative of working conditions in Armenia. However, they document conditions in the worksites studied.

Although these findings suggest that some lead-using worksites in Armenia are not associated with excessive risks for exposure, evidence of high risk was detected in one factory. Specifically, the BLLs in workers and environmental monitoring data from the lead crystal manufacturer indicate the need for improvement of conditions (including engineering controls, housekeeping, work practices, and environmental and employee monitoring) at this factory. The high BLLs measured in workers at this factory probably resulted from a combination of high lead levels in dust and presumed high airborne lead concentrations. Such exposures most likely occur in other lead-using industries in Armenia, particularly as a result of ongoing economic and social change. For example, the current severe electricity shortage and other factors reportedly have prompted the establishment of small, unregulated battery shops, in which environmental controls and worker protections probably are inadequate.

Systematic surveys of lead-using facilities -- especially in industries associated with high risks for excessive lead exposures -- are necessary to characterize lead hazards and to identify workers at risk for lead toxicity. In Armenia and in some other countries, such efforts can be facilitated by establishing local capacity to conduct more complete exposure assessments (including air monitoring) and accurate laboratory analyses of routine blood lead and environmental lead samples.

References

1. Saryan LA, Zenz C. Lead and its compounds. In: Zenz C, ed. Occupational medicine. 3rd ed. St. Louis, Missouri: Mosby, 1994: 506-41.

2. CDC. Occupational lead surveillance -- Taiwan, July-December 1993. MMWR 1995;44:181,187-9.

3. Saryan LA. Monitoring for human exposure to asbestos and toxic metals. Proceedings of the First World Congress of Armenian Engineers, Scientists, and Industrialists. Glendale, California: Armenian Engineers and Scientists of America, Inc., 1989:27-40.

4. Saryan LA. Surreptitious lead exposure from an Asian Indian medication. J Anal Toxicol 1991;15:336-8.

5. NIOSH. NIOSH manual of analytical methods {Method 7082}. 3rd ed. Cincinnati, Ohio: US Department of Health and Human Services, Public Health Service, CDC, 1984; DHHS publication no. (NIOSH)84-100.

6. CDC. Adult blood lead epidemiology and surveillance -- United States, fourth quarter 1994. MMWR 1995;44:286-7.

7. Office of the Federal Register. Code of federal regulations: occupational safety and health standards. Subpart Z: toxic and hazardous substances -- lead. Washington, DC: Office of the Federal Register, National Archives and Records Administration, 1985. (29 CFR section 1910.1025).

8. Department of Housing and Urban Development. Guidelines for the evaluation and control of lead-based paint hazards in housing. Washington, DC: US Department of Housing and Urban Development, June 1995.

AESA is a nonprofit professional organization and UAF is a nonprofit service organization; both are headquartered in Glendale, California.

** The selection of survey sites was primarily dictated by time and external economic constraints; access to energy and raw materials for industry in Armenia had been restricted because of regional political circumstances, which resulted in frequent, unpredictable shutdowns of many factories. Study sites were factories in operation at times that coincided with the investigators' availability.

*** The cutoff level of greater than or equal to 25 ug/dL corresponds to the reporting level in many U.S. states (6), and 40 ug/dL corresponds to the return-to-work (following medical removal for elevated BLL) criterion in the OSHA general industry lead standard (7). An additional cutoff of 65 ug/dL was selected to exceed current permissible levels in the United States and as a level at which overt or clinically observable toxic effects of lead would be expected in adults with chronic occupational exposure.

**** Airborne lead exposures, which are generally the major source of occupational exposure, were not measured in this survey because of technical limitations.

TABLE 1. Blood lead levels (BLLs) * in workers, by facility -- Armenia, 1991
and 1993
================================================================================
                                                     Distribution of samples
                                  BLL (ug/dL)       --------------------------
Survey/                No.    --------------------     >=25    >40    >65
  Facility           Workers  Mean  (SD)    Range     ug/dL  ug/dL  ug/dL
--------------------------------------------------------------------------------
1991 Survey
 Printing plant A      34     14.5 (+/- 6.2)   4-31      1       0      0
 Printing plant B      17      8.9 (+/- 4.3)   3-19      0       0      0
 Research institute    10      3.4 (+/- 1.2)   2- 5      0       0      0
 Crystal factory
  Administration       13     11.1 (+/- 4.7)   4-22      0       0      0
  Production           25     41.2 (+/-19.7)  15-89     20      12      3

1993 Survey +
 Crystal factory
  Administration        5      6.8 (+/- 1.3)   5- 8      0       0      0
  Production           14     45.8 (+/-23.2)   8-82     11       7      5
--------------------------------------------------------------------------------
* A BLL <=9 ug/dL reflects low exposure in adults and is considered "normal."
  The cutoff level of >=25 ug/dL corresponds to the reporting level in many
  states in the United States (6); >40 ug/dL corresponds to the return-to-work
  (following medical removal for elevated BLL) criterion in the Occupational
  Safety and Health Administration lead standard (29 CFR & 1910.1025) (7); and
  >65 ug/dL exceeds current permissible levels in the United States.
+ Because extremely high exposures were identified in 1991, the crystal
  factory was resurveyed in 1993.
================================================================================

TABLE 2. Dust wipe lead levels at the crystal factory -- Armenia, 1993
==========================================================================
                                 No.     Range of lead levels
Site                           samples       (ug/sq ft) *
--------------------------------------------------------------------------
Lead oxide mixing area            4         66,000-415,000
Quartz sand mixing area           4          5,200- 19,800
Potassium nitrate mixing area     2         11,000- 15,500
Glass casting area                2          7,000- 13,700
Artistic engraving                3         10,800- 18,200
Regular engraving                 4          3,800- 51,400
Office hallway floor              2            606-    879
Hands of casting workers          3            288-    852 +
--------------------------------------------------------------------------
* No Occupational Safety and Health Administration standard regulates the
  amount of lead in surface dust. For comparison, recommended clearance
  levels for lead on surfaces after residential lead abatement in the
  United States are 100 ug/sq ft for floors, 500 ug/sq ft for window
  sills, and 800 ug/sq ft for window wells (8).
+ ug per hand).
==========================================================================

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