Holton et al., Characterization of asbestos exposures associated with the use of facial makeups. Risk Analysis, 42, 2129-2139.

Holton and colleagues have performed a risk assessment after measuring asbestos released from several samples of facial makeup. Unfortunately, it is not possible to interpret or generalize their findings because the authors have not described the source(s) of the talc tested or the asbestos concentrations of the samples. The concentration of amphiboles varies widely between sources, and the authors are urged to divulge the locations of the ore bodies providing the talc for their samples, as well as the asbestos concentration of the samples, so that the results may be interpreted and possibly generalized.

A comparison of asbestos fiber potency and elongate mineral particle (EMP) potency for mesothelioma in humans.

Dr. Garabrant presented a paper concerning a comparison of asbestos fiber potency and elongate mineral particle (EMP) potency for mesothelioma in humans at the Elongate Mineral Particles Conference in Charlottesville, Virginia in 2017. I was a participant at the Conference. Following Dr. Garabrant's talk, I rose in question period to point out that he had not considered information about the occurrence of mesothelioma in several cohorts that was published after the studies that he cited. These additional data were still not addressed in the paper published in your Journal. I believe that your readers would be interested in these, so this letter is written to draw the additional data to their attention.

Comments on "Dimensions of elongated mineral particles with implications for pathogenicity and classification as asbestiform versus cleavage fragments".

Roggli and Green have reported their study of the dimensions of fibers extracted from the tissues of cases examined in their laboratory, and have drawn conclusions about the pathogenicity of Elongated Mineral Particles and their classification as asbestiform versus cleavage fragments. There are aspects of their methodology and discussion that would benefit from examination. Roggli and Green have relied upon a paper by Harper et al. for their definitions of asbestiform and cleavage fragments. Unfortunately, they have misinterpreted the work of those authors who have concluded that the best criterion is a particle width <1µm. Roggli and Green conclude that 'Our findings demonstrate the lack of pathogenicity of fibers less than 10 µm long or likelihood of cleavage fragments for fibers less than 10µm long and greater than 1.0µm in diameter has little or no effect on the classification of commercial amphibole fibers using our analytical methodology. On the other hand, both lack of pathogenicity and likelihood of cleavage fragments apply to a significant proportion of noncommercial amphiboles identified using our counting scheme.' This is not true. The study of Roggli and Green was a simple fiber counting study with no control population. The design of such a study does not allow the investigator to draw any conclusions about pathogenicity, or lack thereof.

Relationship between income and mortality in a Canadian family practice cohort.

OBJECTIVE: To examine the relationship between household income and mortality in a primary care cohort while using personal information obtained from clinical records and administrative data linkages to adjust for confounders. DESIGN: Survey and analysis of data from several administrative databases. SETTING: Toronto, Ont. PARTICIPANTS: Patients of an urban academic family practice who were aged between 45 and 74 and who had made at least 3 visits to the clinic between 1996 and 1997. MAIN OUTCOME MEASURES: Patients' self-reported household income. Patients' personal information obtained from clinical records and linkages to administrative data to adjust for confounders; personal information was used to adjust for health factors as confounders of the relationship between income and mortality risk. RESULTS: Of the 1064 patients who received surveys, 519 (49%) responded. There was no significant difference in the mortality rate between nonresponders and responders. Mortality rates were lower than those in the general population throughout follow-up. Within the patient cohort, mortality rates were elevated for smokers, those who had not consumed alcohol in the year before the survey, and those who had been diagnosed with diabetes, hypertension, or cancer before the survey. After all adjustments were made, mortality rates were lower among patients in the higher-income categories than among those with lower household incomes. CONCLUSION: Universal health care does not eliminate income-related differentials in mortality. Differences in health-related behaviour factors are not sufficient to explain the socioeconomic mortality differences within an area. These data suggest that it is not solely personal choice related to health behaviour but that other explanations must be invoked to account for the relationship between lower household income and increased mortality rates.

Asbestos fibres in the lungs of an American mechanic who drilled, riveted, and ground brake linings: a case report and discussion.

In North America and Europe, the use of asbestos in friction products was discontinued before the end of the 20th century. In the developing world, the use of asbestos-containing friction products continues. In 2010, Cely-Garcia and colleagues (Cely-Garcia et al., 2012) sampled three brake repair shops located in Bogota, Colombia. Both asbestos and non-asbestos containing brake linings were sold separately or attached to a shoe. When brake linings are sold separated from the shoe, they must be manipulated to attach them to the shoe before installation. The process starts with the removal of the old brake shoe from the vehicle's brake drum. If the existing brake shoe is to be reused, the old lining needs to be removed and the old shoe must be ground to prepare it for a new lining. Riveting requires drilling holes in the linings and shoes and before installing rivets, the lining must be countersunk. The borders of the lining are bevelled. On some occasions, the entire exposed surface of the lining is ground to make it thinner. Once attached to the shoe, the edges of brake linings may extend beyond the shoe. In this case, it is necessary to cut or grind the edges to match the lining to the shoe before bevelling or grinding. The authors reported that 'the sampling results indicate that the brake mechanics sampled are exposed to extremely high asbestos concentrations (i.e. based on transmission electron microscopy counts), suggesting that this occupational group could be at excess risk of asbestos-related diseases'.

Pneumoconiosis and malignant mesothelioma in a family operated metal casting business that used industrial talc from New York state.

BACKGROUND: The United States is second only to the People's Republic of China in annual talc production. U.S. talc is used in the production of ceramics, paint, paper, plastics, roofing, rubber, cosmetics, flooring, caulking, and agricultural applications. A number of U.S. talc deposits consistently contain talc intergrown with amphiboles such as tremolite and/or anthophyllite. It has long been recognized that miners and millers of talc deposits are at risk for pneumoconiosis and it has recently been reported that it is prudent, on the balance of probabilities, to conclude that dusts from New York State talc ores are capable of causing mesothelioma in exposed workers. This is a report of the diagnosis of pneumoconiosis and mesothelioma in a husband and wife who operated a small metal casting business that used industrial talc from New York as a parting agent. METHODS: Case reports, including medical records and exposure histories, were provided by an attorney who had also commissioned laboratory investigation of the industrial talc product used in the factory. RESULTS: Mrs X was diagnosed with pneumoconiosis characterized by interstitial fibrosis and heavily calcified pleural plaques. Mr X had calcified pleural plaques and developed a fatal pleural mesothelioma. Samples of the industrial talc contained fibrous tremolite and anthophyllite. CONCLUSIONS: The author concludes that end users of industrial talc from New York State may be at risk of pneumoconiosis and malignant disease. End users of talcs from other regions of the United States, where talc formation arose from processes driven by regional metamorphism, might also be at risk.

The analysis of asbestos count data with "nondetects": the example of asbestos fiber concentrations in the lungs of brake workers.

OBJECTIVES: In the analysis of tissue for asbestos fibers, some measurements may be below the analytical detection limit (nondetects). The use of maximum likelihood and survival analysis methods have been recommended to perform comparisons between subjects in the presence of nondetects. When the data consist of "counts" another method is useful. This method is discussed, and illustrated with an analysis of asbestos lung burden data among brake mechanics previously analyzed by other methods. METHODS: Statistical models for count data, namely Poisson and negative binomial regression, were used to compare the asbestos fiber concentrations in the lungs of brake mechanics with those of control subjects. The fit of the models was assessed with an analysis of residuals. RESULTS: The negative binomial regression models fit the data well. The concentrations of Quebec asbestos fibers in the lungs of the brake mechanics were significantly higher than in the control population. CONCLUSIONS: Helsel recommended the use of maximum likelihood and survival analysis methods to perform comparisons in the presence of nondetects. When analyzing asbestos fiber count data, or other count data arising in occupational or environmental health, the use of models such as the Poisson and negative binomial may be added to the analyst's toolbox. Benefits are that neither of these methods requires the substitution of arbitrary values for the nondetects and that programs for the computation of count data models are contained in popular statistical software packages.

The association between chronic exposure to traffic-related air pollution and ischemic heart disease.

Increasing evidence links air pollution to the risk of cardiovascular disease. This study investigated the association between ischemic heart disease (IHD) prevalence and exposure to traffic-related air pollution (nitrogen dioxide [NO2], fine particulate matter [PM2.5], and ozone [O3]) in a population of susceptible subjects in Toronto. Local (NO2) exposures were modeled using land use regression based on extensive field monitoring. Regional exposures (PM2.5, O3) were modeled as confounders using inverse distance weighted interpolation based on government monitoring data. The study sample consisted of 2360 patients referred during 1992 to 1999 to a pulmonary clinic at the Toronto Western Hospital in Toronto, Ontario, Canada, to diagnose or manage a respiratory complaint. IHD status was determined by clinical database linkages (ICD-9-CM 412-414). The association between IHD and air pollutants was assessed with a modified Poisson regression resulting in relative risk estimates. Confounding was controlled with individual and neighborhood-level covariates. After adjusting for multiple covariates, NO2 was significantly associated with increased IHD risk, relative risk (RR) = 1.33 (95% confidence interval [CI]: 1.2, 1.47). Subjects living near major roads and highways had a trend toward an elevated risk of IHD, RR = 1.08 (95% CI: 0.99, 1.18). Regional PM2.5 and O3 were not associated with risk of IHD.

Malignant mesothelioma incidence among talc miners and millers in New York State.

BACKGROUND: There is controversy about the potential for dust from the talc mines and mills of New York State to cause mesothelioma. Honda et al. published a study of mortality among New York talc workers and concluded that it was unlikely that the two deaths from mesothelioma were caused by talc ore dust. However, fibers of tremolite and anthophyllite have been found in the lungs of talc workers and Hull concluded that "New York talc exposure is associated with mesothelioma, and deserves further public health attention." METHODS: Data concerning additional cases of mesothelioma in the cohort have been posted by NIOSH. I used information from the NIOSH website and the Honda report to analyze the incidence of mesothelioma during the years 1990-2007. RESULTS: There were at least five new cases of mesothelioma in the cohort and mesothelioma incidence rates were at least five (1.6-11.7) times the rate in the general population (P < 0.01). CONCLUSIONS: I conclude that: (1) mesothelioma has been diagnosed among members of the cohort at a rate in excess of that in the general population; (2) fibers of tremolite and anthophyllite have been detected in dust and the lungs of talc workers; and (3) these fibers are known causes of mesothelioma. It is prudent, on the balance of probabilities, to conclude that dusts from New York State talc ores are capable of causing mesothelioma in exposed individuals.

Silica exposure assessment in a mortality study of Vermont granite workers.

A study of past silica and respirable dust exposures in the Vermont granite industry was conducted to develop a job exposure matrix (JEM) that used 5204 industrial hygiene measurements made from 1924-2004. The construction of the JEM involved data entry from several original sources into an Excel database that was reviewed later to ensure accuracy. Exposure measurements by job or location were grouped in two broad categories of quarry or shed and then into 22 job classes. Missing exposure data by time period were computed, taking into account improvements in dust control and periods of significant reduction in dustiness. Percent free silica (α-quartz) in respirable dust was estimated to be 11.0% based on previous published studies in Vermont and on data in the current database. About 60% of all measurement data (primarily from years prior to 1972) were obtained using the impinger and expressed in millions of particles per cubic foot (mppcf), which were converted to equivalent respirable free silica concentrations using the conversion of 10 mppcf = 0.1 mg/m(3) of respirable silica. For impinger data, respirable dust was calculated by multiplying respirable silica by a factor of 9.091 to reflect that the respirable silica was 11.0% respirable dust. This JEM has been used in a recent epidemiologic study to assess mortality in Vermont granite workers and to examine the relationships among mortality from silicosis, lung cancer, and other nonmalignant respiratory diseases.

Malignant mesothelioma among employees of a Connecticut factory that manufactured friction materials using chrysotile asbestos.

There is ongoing argument about the potency of chrysotile asbestos to cause malignant mesothelioma. Risk assessment for chrysotile is influenced by the alleged absence of mesotheliomas among workers at the Raybestos Manhattan friction products plant in Connecticut, a plant that essentially used only chrysotile asbestos. Regrettably, the statement that there is an absence of mesothelioma deaths in the Connecticut plant is false. In this paper, we report on our review of the work histories and pathological reports of five individuals from the Connecticut plant who were diagnosed with mesothelioma. We discuss the Connecticut plant in relation to the most recent epidemiological information for chrysotile. Calculation suggests that mesothelioma rates at this plant were similar to those observed among Quebec miners and the South Carolina textile plant. We urge everyone concerned with the risk assessment of chrysotile asbestos to make use of all available data.

Absence of radiographic asbestosis and the risk of lung cancer among asbestos-cement workers: Extended follow-up of a cohort.

BACKGROUND: It has been a matter of controversy whether there is an increased risk of lung cancer among asbestos-exposed workers without radiographic asbestosis. A previous study of lung cancer risk among asbestos-cement workers has been updated with an additional 12 years of follow-up. METHODS: Subjects had received radiographic examination at 20 and 25 years from first exposure to asbestos. Radiographs were interpreted by a single National Institute of Safety and Health (NIOSH)-certified B-reader using the 1971 International Labor Office (ILO) Classification of the pneumoconioses as reference standard. Asbestosis was defined as an ILO coding of 1/0 or higher. Standardized Mortality Ratios (SMRs) were calculated using the general population of Ontario as reference. RESULTS: Among asbestos-cement workers without radiographic asbestosis at 20 years latency the lung cancer SMR was 3.84 (2.24-6.14). Among workers without asbestosis when examined at 25 years latency the SMR was 3.69 (1.59-7.26). CONCLUSIONS: Workers from an Ontario asbestos-cement factory who did not have radiographic asbestosis at 20 or 25 years from first exposure to asbestos continued to have an increased risk of death from lung cancer during an additional 12 years of follow-up.