RESUMEN
Lumber Liquidators (LL) Chinese-manufactured laminate flooring (CLF) has been installed in >400,000 U.S. homes over the last decade. To characterize potential associated formaldehyde exposures and cancer risks, chamber emissions data were collected from 399 new LL CLF, and from LL CLF installed in 899 homes in which measured aggregate indoor formaldehyde concentrations exceeded 100 µg/m3 from a total of 17,867 homes screened. Data from both sources were combined to characterize LL CLF flooring-associated formaldehyde emissions from new boards and installed boards. New flooring had an average (±SD) emission rate of 61.3 ± 52.1 µg/m2 -hour; >one-year installed boards had â¼threefold lower emission rates. Estimated emission rates for the 899 homes and corresponding data from questionnaires were used as inputs to a single-compartment, steady-state mass-balance model to estimate corresponding residence-specific TWA formaldehyde concentrations and potential resident exposures. Only â¼0.7% of those homes had estimated acute formaldehyde concentrations >100 µg/m3 immediately after LL CLF installation. The TWA daily formaldehyde inhalation exposure within the 899 homes was estimated to be 17 µg/day using California Proposition 65 default methods to extrapolate cancer risk (below the regulation "no significant risk level" of 40 µg/day). Using a U.S. Environmental Protection Agency linear cancer risk model, 50th and 95th percentile values of expected lifetime cancer risk for residents of these homes were estimated to be 0.33 and 1.2 per 100,000 exposed, respectively. Based on more recent data and verified nonlinear cancer risk assessment models, LL CLF formaldehyde emissions pose virtually no cancer risk to affected consumers.
Asunto(s)
Materiales de Construcción , Formaldehído/análisis , Neoplasias/inducido químicamente , Medición de Riesgo , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Algoritmos , California , China , Formaldehído/efectos adversos , Humanos , Exposición por Inhalación/análisis , Modelos Lineales , Neoplasias/prevención & control , Hipersensibilidad Respiratoria/prevención & control , Estados Unidos , United States Environmental Protection AgencyRESUMEN
This study's objective is to assess the risk of asbestos-related disease being contracted by past users of cosmetic talcum powder. To our knowledge, no risk assessment studies using exposure data from historical exposures or chamber simulations have been published. We conducted activity-based sampling with cosmetic talcum powder samples from five opened and previously used containers that are believed to have been first manufactured and sold in the 1960s and 1970s. These samples had been subject to conflicting claims of asbestos content; samples with the highest claimed asbestos content were tested. The tests were conducted in simulated-bathroom controlled chambers with volunteers who were talc users. Air sampling filters were prepared by direct preparation techniques and analyzed by phase contrast microscopy (PCM), transmission electron microscopy (TEM) with energy-dispersive x-ray (EDX) spectra, and selective area diffraction (SAED). TEM analysis for asbestos resulted in no confirmed asbestos fibers and only a single fiber classified as "ambiguous." Hypothetical treatment of this fiber as if it were asbestos yields a risk of 9.6 × 10-7 (under one in one million) for a lifetime user of this cosmetic talcum powder. The exposure levels associated with these results range from zero to levels far below those identified in the epidemiology literature as posing a risk for asbestos-related disease, and substantially below published historical environmental background levels. The approaches used for this study have potential application to exposure evaluations of other talc or asbestos-containing materials and consumer products.
Asunto(s)
Cosméticos/toxicidad , Polvos/toxicidad , Medición de Riesgo/métodos , Talco/toxicidad , Aire , Amianto/análisis , Cosméticos/análisis , Humanos , Exposición por Inhalación/análisis , Microscopía Electrónica de Transmisión , Microscopía de Contraste de Fase , Fibras Minerales/análisis , Fibras Minerales/toxicidad , Exposición Profesional , Polvos/análisis , Probabilidad , Respiración , Talco/análisis , Termogravimetría , Rayos XRESUMEN
OBJECTIVE: We compared, updated, and expanded the analyses of two previous meta-analyses of personal hair dye exposure and bladder cancer, and briefly discussed the biological plausibility of a systemic hazard to human health from exposure to para-phenylenediamine (PPD), a key chemical in hair dyes. METHODS: The meta-analysis included 11 case-control studies and one cohort study. We evaluated heterogeneity across studies and conducted sensitivity and influence analyses. RESULTS: No association was found between any personal use of hair dye and bladder cancer among women (meta-relative risk [mRR] = 1.01, 95% CI: 0.89-1.14), men (mRR = 0.82, 95% CI: 0.60-1.14), or both sexes combined (mRR = 0.97, 95% CI: 0.87-1.08). No statistically significant mRRs were found among the studies that reported data for permanent hair dye use (mRR = 1.06, 95% CI: 0.89-1.27), duration of any hair dye use (mRR = 1.00, 95% CI: 0.85-1.19), duration of permanent hair dye use (mRR = 1.31 95% CI 0.78-2.19), lifetime applications of any hair dye use (mRR = 1.12 (95% CI: 0.72-1.72) or permanent hair dye use (mRR = 1.59, 95% CI 0.69-3.64), or dark color hair dye use (mRR = 0.94, 95% CI: 0.74-1.19). CONCLUSION: The results of this meta-analysis of epidemiologic studies do not indicate a causal association between personal hair dye use and bladder cancer.
Asunto(s)
Tinturas para el Cabello/efectos adversos , Fenilendiaminas/efectos adversos , Neoplasias de la Vejiga Urinaria/etiología , Femenino , Humanos , Masculino , RiesgoRESUMEN
Work-related exposures potentially associated with a cluster of brain tumors at a petroleum exploration and extraction research facility were evaluated in a nested case-control study. Fifteen cases were identified in the original cohort and 150 matched controls were selected. Odds ratios (ORs) for occupational exposure to petroleum, radiation, solvents, magnetic fields, and work activities were near or below 1.0. ORs near 1.5 were observed for: working with computers (OR = 1.47; 95% confidence interval [CI] = 0.30-9.35); work-related travel (OR = 1.48; 95% CI = 0.25-5.95), and travel immunizations (OR = 1.62; 95% CI = 0.23-9.45). Higher ORs were observed for work in administrative and marketing buildings and for achieving a master's or higher degree (OR = 2.0, 95% CI = 0.4-10.7). While some ORs above 1.5 were noted, no work-related chemical and physical exposures were significantly associated with the occurrence of brain tumors among employees at this facility.