Assessment of environmental and domestic exposure to tremolite in New Caledonia

Our plain-English summary of Assessment of environmental and domestic exposure to tremolite in New Caledonia, by D. Luce, M.A. Billon-Galland, I. Bugel, et al (Archives of Environmental Health, 2004).

The study

• Authors: D. Luce, M.A. Billon-Galland, I. Bugel, P. Goldberg, C. Salomon, J. Févotte, M. Goldberg
• Journal: Archives of Environmental Health
• Published: 2004;59(2):91-100
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In this study, the authors characterized exposure to asbestos in the population of New Caledonia, an area where a high mesothelioma incidence was found to be associated with the use of a tremolite-containing whitewash on dwellings. The authors collected airborne samples from various sources. Lung tissue samples or bronchoalveolar lavage fluids were available for 80 subjects, who were interviewed regarding their residential and occupational histories. The authors analyzed all samples by analytical transmission electron microscopy. Results indicated that the use of the tremolite-based whitewash may generate high airborne fiber levels and result in asbestos lung contents comparable with those observed in occupational settings. The highest airborne tremolite concentrations were reached during sweeping in whitewashed houses. Lung concentrations of tremolite fibers were significantly higher in subjects exposed to the whitewash than in unexposed subjects, and the concentrations increased with the duration of exposure.

In plain English

This study measured asbestos exposure in New Caledonia, where a tremolite-containing whitewash called pö had been used on houses. The authors collected 68 air samples in four villages, including a control village that never used pö. They also analyzed 52 lung tissue and 28 lung-wash (bronchoalveolar lavage) samples from patients, mainly with lung cancer or pleural mesothelioma. The highest airborne tremolite levels, in the order of 1000 fibers per liter, were inside whitewashed houses, especially during cleaning. Women or girls almost always cleaned. In lung tissue, the average (geometric mean) tremolite concentration was significantly higher in 10 pö-exposed subjects (5.91 fibers per microgram of dry lung) than in 42 unexposed subjects (0.14). In lung-wash fluid the difference was not statistically significant. Chrysotile was found in 34% of exposed and 15% of unexposed subjects, but overall concentrations were not significantly associated with pö. The authors concluded that the whitewash may produce high airborne fiber levels and lung contents comparable with occupational settings. They noted that samples came from sick patients and probably did not reflect the general population's lung burden.

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: Environmental air-sampling survey combined with analysis of asbestos fibers and asbestos bodies in lung samples from patients with and without exposure to the whitewash (cross-sectional)
• Who was studied: Air samples from four villages in New Caledonia: Montfaoué, Petit Couli, Nédivin, and the control village Unia. A daily-activity survey of 80 randomly selected villagers, of whom 78 were interviewed. 52 lung tissue samples and 28 bronchoalveolar lavage fluid samples from patients treated in New Caledonia; 10 tissue and 23 lavage samples came from subjects exposed to pö.
• Exposure: Domestic and environmental exposure to tremolite asbestos from a whitewash made from local outcroppings (pö), applied to indoor and outdoor house walls. An industrial hygienist assessed occupational asbestos exposure separately.
• Main results:
  • The highest airborne tremolite concentrations, in the order of 1000 fibers per liter, were found inside houses whitewashed with pö, particularly during cleaning. Cleaning in this study was done after spraying water on the floor.
  • Outdoors near whitewashed houses, tremolite concentrations were lower but could reach 12 fibers per liter.
  • In the two villages where pö was still used, tremolite was also found at lower levels in houses not whitewashed with pö, especially during cleaning (4 fibers per liter).
  • In the control village (Unia), no asbestos fibers were detected apart from a low chrysotile concentration in street samples.
  • The daily-activity survey found that women spent more time indoors or near their house than men did, and that women or girls almost always did the house cleaning.
  • Tremolite fibers were detected in 24 (75%) of the pö-exposed subjects and in 15 (32%) of the unexposed subjects. The p-value is printed as 0.001, but its comparison sign was lost in the text.
  • Chrysotile fibers were detected in 11 (34%) of the pö-exposed subjects and in 7 (15%) of the unexposed subjects. The p-value is printed as 0.05, but its comparison sign was lost in the text.
  • In lung tissue, the geometric mean tremolite concentration was 5.91 fibers per microgram of dry lung in the 10 pö-exposed subjects and 0.14 in the 42 unexposed subjects. The authors reported this difference as statistically significant.
  • In lavage fluid, the geometric mean tremolite concentration was 460 fibers per ml in 22 pö-exposed subjects and 166 in 5 unexposed subjects. Concentrations were higher in exposed subjects and rose with duration of exposure, but these differences were not statistically significant.
  • Overall, chrysotile concentration in lung tissue was not significantly associated with exposure to pö. However, significant associations were found among women and among subjects not occupationally exposed to asbestos. In lavage fluid, chrysotile concentrations were not associated with exposure to pö.
  • Asbestos body concentrations above 1 per ml of lavage fluid or 1000 per gram of dry lung were found in 56.5% of pö-exposed subjects (13 of 23) and in 16.7% of never-exposed subjects (7 of 42).
  • The authors found no significant difference in tremolite lung burden between men and women.
• The authors' conclusion: The authors concluded that use of the tremolite-based whitewash in New Caledonia may generate high airborne fiber levels and may result in asbestos lung contents comparable with those observed in occupational settings.
• Limitations the authors state:
  • Lung samples came only from patients with respiratory disease who needed bronchoscopy or surgery, so the fiber concentrations probably did not reflect the asbestos lung burden of the population.
  • Almost all lavage samples came from mesothelioma patients and almost all lung tissue samples from lung cancer patients. This limited comparisons by diagnosis.
  • Asbestos bodies were counted in only 13 lavage samples, all from pö-exposed subjects, so no exposed-versus-unexposed comparison was possible for lavage fluid.

Topics

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

Medical terms in this study, explained in our Lexicon: Tremolite, New Caledonia, Mesothelioma, Whitewash, Bronchoalveolar Lavage (BAL), Analytical Transmission Electron Microscopy (ATEM).

Related studies

• Environmental exposure to tremolite and respiratory cancer in New Caledonia: a case-control study — D. Luce, I. Bugel, et al. (2000)
• Occupational exposures and lung cancer in New Caledonia — G. Menvielle, D. Luce, et al. (2003)
• Environmental mesothelioma associated with tremolite asbestos: lessons from the experiences of Turkey, Greece, Corsica, New Caledonia and Cyprus — S.H. Constantopoulos (2008)
• Environmental airborne tremolite asbestos pollution and pleural plaques in Afghanistan — C. Voisin, I. Marin, et al. (1994)
• Development of a multidimensional housing and environmental quality index (HEQI): application to the American Housing Survey — M.T. Chu, A. Fenelon, et al. (2022)
• Pleural mesothelioma in New Caledonia: associations with environmental risk factors — F. Baumann, P. Maurizot, et al. (2011)

Browse more research in Archives of Environmental Health, or return to medical research.