North-south gradient of mesothelioma and asbestos consumption-production in the United States-Progresses since the 1st asbestos partial ban in 1973

Our plain-English summary of North-south gradient of mesothelioma and asbestos consumption-production in the United States-Progresses since the 1st asbestos partial ban in 1973, by H. Sun (American Journal of Industrial Medicine, 2019).

The study

• Author: H. Sun
• Journal: American Journal of Industrial Medicine
• Published: 2019;62(4):337-346
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Temporal trends and broad geographical distributions of asbestos use and the incidence of malignant mesothelioma (MM) in the US still need to be studied.

Methods: Data on asbestos consumption and production between 1900 and 2015 and MM mortality and incidence rates between 1975 and 2015 in the US were examined. Spatial distributions of MM mortality and incidence rates and their association with climate zone were analyzed.

Results: Decline of MM incidence and mortality rates in the US occurred about 20 years after the peak of asbestos consumption-production in 1973. There are apparent north-south (N-S) gradients in MM mortality and incidence rates in the US.

Conclusion: Recent decline of MM incidence and mortality rates in the US may be associated with reduced US asbestos consumption. N-S MM gradients between 1999 and 2015 were likely related to larger asbestos requirements in building materials in the northern states.

© 2019 Wiley Periodicals, Inc.

In plain English

This ecological study by a single author used publicly available US government data to compare asbestos consumption and production from 1900 to 2015 with malignant mesothelioma rates in the 48 contiguous states. It had no information on individual people's asbestos exposure. US asbestos use peaked at over 803,000 tons in 1973 and fell to about 343 tons in 2015. Mesothelioma incidence in men rose until 1992 and then fell, about 20 years after the 1973 peak. In women it rose until 1983 and then stayed relatively flat. Death rates from 1999 to 2015 showed an apparent north-south pattern. Northern, cold-climate states had a mortality rate ratio of 1.29 (95% confidence interval 1.25 to 1.33) compared with southern, warm-climate states. Most states' death rates declined, but three states still showed an upward trend. The author concluded the decline may be associated with reduced asbestos use. The author also believed a significant portion of the north-south difference relates to greater past handling of asbestos insulation in colder northern states, while noting that other risk factors need study.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Ecological study: a statistical analysis of publicly available national data on asbestos use, mesothelioma rates and climate zones, with no individual-level exposure data
• Who was studied: The 48 contiguous US states. Mesothelioma deaths (CDC death-certificate data, 1999-2015), state incidence (CDC, 1999-2013) and national incidence for men and women (SEER, 1975-2013), plus US asbestos consumption and production data, 1900-2015
• Exposure: National asbestos consumption, production and end uses, studied at population level (fiber types were not analyzed separately). Climate zone was used as a stand-in for how much insulation buildings required. The author also considered asbestos mine and occurrence sites, World War II shipyard employment, and coal production
• Main results:
  • US asbestos use fell from over 803,000 tons in the peak year of 1973 to about 343 tons in 2015
  • National mesothelioma incidence in men rose from 1975 to 1992 and then declined. In women it rose before 1983 and then stayed relatively flat or fluctuated
  • The gap between peak asbestos consumption and peak mesothelioma incidence was about 20 years for men (1973 to 1992) and about 11 years for women (1973 to 1983)
  • Average state mesothelioma death rates from 1999 to 2015 showed an apparent north-south gradient, with higher rates in cold climate zones and lower rates in warm climate zones
  • Mesothelioma mortality rate ratio for northern states (climate zones 6 and 7) compared with southern states (zones 1, 2 and 3), all races and both sexes: 1.29 (95% CI 1.25-1.33). The ratio for white men and for white women was 1.31 (95% CI 1.26-1.37) each
  • Removing three coastal states with high shipyard activity (FL, LA and DE) strengthened the link between climate zone and mesothelioma rates. The R-squared rose from 0.26 to 0.48 for incidence and from 0.30 to 0.41 for mortality
  • The five states with the highest average mesothelioma death rates from 1999 to 2015 were Maine, Washington, Wyoming, West Virginia and New Jersey
  • Overall, mesothelioma incidence and death rates fell across the 48 states, but three states still showed an upward mortality trend. Eight states showed upward incidence trends, not all of them statistically significant
  • The ratio of men's to women's age-adjusted mesothelioma death rates from 1999 to 2015 was about 3.5
• The authors' conclusion: The author concluded that the recent decline in mesothelioma may be associated with reduced US asbestos consumption. The author believed a significant portion of the north-south gradient is related to the greater number of workers who processed asbestos materials, mainly for insulation, in colder northern states, and that secondary exposure in old buildings may also have contributed
• Limitations the authors state:
  • There was no individual-level asbestos exposure information for the mesothelioma cases. Exposure was linked only ecologically, through industry and usage trends
  • Other possible risk factors for mesothelioma need further study, including a simian virus, the mineral erionite, radiation exposure and genetic predisposition
  • Mesothelioma incidence data were not available for all 48 states for 1999-2015
  • Differences by latitude in vitamin D and heat shock protein levels might also affect mesothelioma and the north-south gradient
  • The SEER cancer registry data do not cover the whole US population

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile, Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Malignant Mesothelioma, Incidence.

Related studies

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• Prediction in the face of uncertainty: the United States versus Reserve Mining Company — A.L. Brown (1986)
• Asbestos-related disease in South Africa: the social production of an invisible epidemic — L. Braun, S. Kisting (2006)
• Malignant mesothelioma incidence among talc miners and millers in New York State — M.M. Finkelstein (2012)
• Mesothelioma in the United States. Incidence in the 1970's — M.W. Hinds (1978)
• Geologic occurrences of erionite in the United States: an emerging national public health concern for respiratory disease — B.S. Van Gosen, T.A. Blitz, et al. (2013)

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