RESUMEN
It has long been recognized that amphibole minerals, such as cleavage fragments of tremolite and anthophyllite, may exist in some talc deposits. We reviewed the current state of the science regarding the factors influencing mesotheliogenic potency of cleavage fragments, with emphasis on those that may co-occur in talc deposits, including dimensional and structural characteristics, animal toxicology, and the most well-studied cohort exposed to talc-associated cleavage fragments. Based on our review, multiple lines of scientific evidence demonstrate that inhaled cleavage fragments associated with talc do not pose a mesothelioma hazard.
Asunto(s)
Asbestos Anfíboles , Talco , Talco/química , Humanos , Animales , Mesotelioma/inducido químicamente , Exposición Profesional/efectos adversosRESUMEN
Talc is used in cosmetic products to confer desirable properties, such as moisture absorption and smooth texture, to the finished products. Concerns have been raised about the potential presence of asbestos in products containing cosmetic talc. Reconstruction of potential asbestos exposure from the use of cosmetic talc products (assuming a trace level of asbestos) requires consideration of consumer use patterns. Although application generally only lasts seconds, exposure theoretically may continue if the consumer remains in the immediate vicinity. Most published exposure measurements have not adequately characterized the potential for continued exposure. In this analysis, estimates and measurements of airborne asbestos fiber concentrations associated with cosmetic talc use from 10 published studies were used as inputs to an exponential decay model to estimate "worst-case" exposure during and following application. The resulting geometric mean 30-min time-weighted average (TWA) concentrations were 0.006 f/cc for both puff and shaker application, for diapering, 0.0001 f/cc (adult applying baby powder) and 0.0002 f/cc (infant), and for makeup application, 0.0005 f/cc. Application of an exponential decay model to measured or estimated asbestos concentrations associated with the use of cosmetic talc products yields a conservative means to comprehensively reconstruct such exposures. Moreover, our results support that, if a cosmetic talc powder product contained a trace level of asbestos fibers, the "worst-case" airborne asbestos exposure associated with its application is low.
Asunto(s)
Amianto , Exposición Profesional , Humanos , Talco/análisis , Polvos , Monitoreo del Ambiente , Amianto/análisis , Exposición Profesional/análisisRESUMEN
Developmental exposure to phthalates has been implicated as a risk for obesity; however, epidemiological studies have yielded conflicting results and mechanisms are poorly understood. An additional layer of complexity in epidemiological studies is that humans are exposed to mixtures of many different phthalates. Here, we utilize an established mouse model of perinatal exposure to investigate the effects of three phthalates, diethylhexyl phthalate (DEHP), diisononyl phthalate (DINP) and dibutyl phthalate (DBP), on body weight and organ weights in weanling mice. In addition to individual phthalate exposures, we employed two mixture exposures: DEHP+DINP and DEHP+DINP+DBP. Phthalates were administered through phytoestrogen-free chow at the following exposure levels: 25 mg DEHP/kg chow, 25 mg DBP/kg chow and 75 mg DINP/kg chow. The viable yellow agouti (A vy ) mouse strain, along with measurement of tail DNA methylation, was used as a biosensor to examine effects of phthalates and phthalate mixtures on the DNA methylome. We found that female and male mice perinatally exposed to DINP alone had increased body weights at postnatal day 21 (PND21), and that exposure to mixtures did not exaggerate these effects. Females exposed to DINP and DEHP+DINP had increased relative liver weights at PND21, and females exposed to a mixture of DEHP+DINP+DBP had increased relative gonadal fat weight. Phthalate-exposed A vy /a offspring exhibited altered coat color distributions and altered DNA methylation at intracisternal A-particles (IAPs), repetitive elements in the mouse genome. These findings provide evidence that developmental exposures to phthalates influence body weight and organ weight changes in early life, and are associated with altered DNA methylation at IAPs.
Asunto(s)
Peso Corporal/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Genes de Partícula A Intracisternal/genética , Tamaño de los Órganos/efectos de los fármacos , Ácidos Ftálicos/toxicidad , Animales , Peso Corporal/genética , Metilación de ADN/efectos de los fármacos , Epigénesis Genética/efectos de los fármacos , Femenino , Masculino , Ratones , Modelos Animales , Tamaño de los Órganos/genética , Embarazo , Factores Sexuales , DesteteRESUMEN
The authors inform nurses about their responsibility under the Americans with Disabilities Act to ensure equal access to health services and health education. This article is divided into two parts: (1) The Americans with Disabilities Act (ADA) is presented particularly in relation to health teaching. (2) Selected disabilities and helpful tips for positive interaction are discussed.