Frank B. Stern

Proportionate mortality among unionized roofers and waterproofers

BACKGROUND The United Union of Roofers, Waterproofers, and Allied Workers (UURWAW) is one of the 15 building and construction trades departments in the AFL-CIO. The U.S. roofing industry, including both roofing and waterproofing applications, both unionized and nonunionized, comprises about 25,000 firms, employing approximately 300,000 people, about 200,000 of whom are involved in the application of roofs. The specific toxins to which roofers may be exposed at the job site include, among others, bitumens (asphalt and/or coal tar pitch) as well as asbestos and fiberglass from roof removal operations. Excess deaths from occupational injuries are also of concern. METHODS This study evaluated causes of mortality among 11,144 members of the UURWAW. Age-adjusted proportionate mortality ratios (PMRs) were computed with 95% confidence intervals (CI) using U.S. age-, gender-, and race-specific proportional mortality rates for the years of the study, 1950-1996. RESULTS Statistically significant increased PMRs were found for all injuries (PMR = 142, CI = 134-150), especially falls (PMR = 464, CI = 419-513) and other injuries (PMR = 121, CI = 107-137), cancers of the lung (PMR = 139, CI = 131-148), bladder (PMR = 138, CI = 111-170), esophagus (PMR = 134, CI = 107-166), larynx (PMR = 145, CI = 106-193), and cancers of other and unspecified sites (PMR = 130, CI = 112-149), pneumoconioses and other nonmalignant respiratory diseases (PMR = 115, CI = 103-128), and homicides (PMR = 153, CI = 135-172). The occupational exposures which may have contributed to the excess risks of malignant and nonmalignant respiratory diseases include, among others, asphalt fumes, coal tar pitch volatiles and asbestos; however, cigarette smoking must also be considered a contributing factor. CONCLUSIONS The present study underscores the need to control airborne exposures to hazardous substances and especially to examine fall prevention efforts within the roofing industry. Am. J. Ind. Med. 37:478-492, 2000. Published 2000 Wiley-Liss, Inc.

Proportionate mortality among unionized construction operating engineers

This report presents the results of proportionate mortality ratios (PMR) and proportionate cancer mortality ratios (PCMR) among 15,843 members of the International Union of Operating Engineers who had died between 1988-1993. Operating engineers represent one of the 15 unions in the Building and Construction Trades Department and are responsible for the operation and maintenance of heavy earthmoving equipment used in the construction of buildings, bridges, roads, and other facilities. Using U.S. proportionate cancer mortality as the referent, statistically significant elevated mortality was observed for cancers of the lung (PCMR = 1.14, 95% confidence interval (CI) = 1.09-1.19) and bone (PCMR = 2.14, CI = 1.19-3.52). Using U.S. proportionate mortality as the referent, statistically significant elevated mortality was observed for other benign and unspecified neoplasms (PMR = 1.54, CI = 1.09-2.13), emphysema (PMR = 1.37, CI = 1.20-1.55), other injuries (PMR = 1.43, CI = 1.20-1.70) (which included crushing under/in machinery, tractor rollover, run over by crane), and suicide (PMR = 1.22, CI = 1.06-1.40). The PMR for leukemia, and aleukemia (PMR = 1.19, CI = 1.02-1.37), but not the PCMR (1.07, CI = 0.92-1.24), was also significantly elevated. Some of the occupational exposures that may have contributed to these excesses include diesel exhaust, asphalt and welding fumes, silica dust, ionizing radiation, and coal tar pitch. The present study underscores the need to control airborne exposures to these substances and for injury prevention efforts aimed at operating engineers in the construction industry.

Underlying and multiple cause mortality in a cohort of workers exposed to aromatic amines.

BACKGROUND The National Institute for Occupational Safety and Health (NIOSH) has previously conducted studies of bladder cancer incidence and mortality at a synthetic dye plant that manufactured beta-naphthylamine from 1940 through 1979. This report extends the period of mortality follow-up 13 years and analyzes both underlying and nonunderlying causes of death. METHODS The vital status of each cohort member, as of December 31, 1992, was determined by using the National Death Index and information from the Internal Revenue Service and the U.S. Postal Service. The NIOSH life table analysis system (LTAS) was used to generate person-year-at-risk and the expected numbers of death for 92 categories of death, using several referent rates (U.S. underlying, Georgia underlying, U.S. multiple cause). RESULTS There were three bladder cancer deaths listed as underlying cause, yielding a standardized mortality ratio (SMR) based on U.S. rates of 2.4 (95% confidence interval (CI) = 0.5, 7.0) and a total of eight bladder cancers listed anywhere on the death certificates (SMR based on multiple cause referent rates = 5.6; 95% CI = 2.4, 11.1). Mortality from esophageal cancer, which had been significantly elevated in the previous study, was no longer significantly elevated (SMR = 2.0; 95% CI = 0.8, 4.1). Mortality from all causes was significantly higher than expected (SMR = 1.5; 95% CI = 1.3, 1.6). CONCLUSIONS The elevated bladder cancer risk in this cohort was detected by the multiple cause, but not the underlying cause, analysis. Elevated mortality from other causes of death, especially among short-term workers, may be related to regional and lifestyle factors.

Expanded analysis of injury mortality among unionized construction workers

BACKGROUND To evaluate the utility of expanding the number and precision of injury categories used in previous occupational mortality studies, this study reanalyzed data from four previous studies of unionized construction workers (construction laborers, ironworkers, sheet metal workers, and operating engineers), by expanding the number of injury categories from 6 to 33. METHODS Proportionate mortality ratios (PMRs) were computed using the distribution of deaths from the National Occupational Mortality Surveillance System, a mortality surveillance system from 28 states, as a comparison. A blue collar comparison group was also used in additional analyses to adjust for socioeconomic and other factors. RESULTS This reanalysis identified significantly elevated PMRs in at least one of the four worker groups for falls, motor vehicle crashes, machinery incidents, electrocutions, being struck by falling objects, being struck by flying objects, explosions, suffocation, and water transport incidents. Limiting the comparison population to deaths among blue collar workers did not change the results substantially. CONCLUSIONS This study demonstrates that increasing the precision of categories of death from injury routinely used in mortality studies will provide improved information to guide prevention. Am. J. Ind. Med. 37:364-373, 2000. Published 2000 Wiley-Liss, Inc.