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1.
J Appl Toxicol ; 40(1): 72-86, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31231852

RESUMO

A literature review and health effects evaluation were conducted for n-butanol, a chemical that occurs naturally in some foods, which is an intermediate in the production of butyl esters and can be used as a gasoline additive or blend. Studies evaluating n-butyl acetate were included in the review as n-butyl acetate is rapidly converted to n-butanol following multiple routes of exposure. The primary n-butanol health effects identified were developmental and nervous system endpoints. In conducting the literature review and evaluating study findings, the following observations were made: (1) developmental findings were consistently identified; (2) neurodevelopmental findings were inconsistent; (3) evidence for nervous system effects was weak; (4) comparing internal doses from oral and inhalation exposures using physiologically based pharmacokinetic models introduces uncertainties; and (5) a lack of mechanistic information for n-butanol resulted in the reliance on mechanistic data for ethanol, which may or may not be applicable to n-butanol. This paper presents findings from a literature review on the health effects of n-butanol and proposes research to help reduce uncertainty that exists due to database limitations.


Assuntos
1-Butanol/toxicidade , Acetatos/toxicidade , Poluentes Ambientais/toxicidade , Sistema Nervoso/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Testes de Toxicidade , 1-Butanol/farmacocinética , Acetatos/farmacocinética , Animais , Desenvolvimento Embrionário/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/farmacocinética , Feminino , Humanos , Sistema Nervoso/crescimento & desenvolvimento , Síndromes Neurotóxicas/embriologia , Síndromes Neurotóxicas/fisiopatologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Medição de Risco , Toxicocinética
2.
Environ Res ; 154: 35-41, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28024226

RESUMO

Data from the 2001-2004 National Health and Nutrition Examination Survey (NHANES) were used to evaluate serum concentrations of polychlorinated biphenyls (PCBs) in women of reproductive age, with or without a history of breastfeeding. Analytical data for PCBs 138, 153, and 180 were used along with responses to the NHANES Reproductive Health questions: [Have you] breastfed any of your children? " and "[What] number of children [have been] breastfed [for] at least 1 month? " PCB concentrations were found to be significantly lower among 15-44 year old women who had a history of breastfeeding compared to those who had not breastfed any of their children. Based on data for 474 women, ages 15-44 years, mean serum PCB 138, 153, and 180 concentrations were 16.4, 21.4, and 14.3ng/g lipid for women who have a history of breastfeeding, and 24.0, 30.0, and 21.4ng/g lipid for women who have not breastfed, respectively. These results were weighted using the 2001-2004 sample weights provided by NHANES to represent over 27 million U.S. women. PCB concentrations were also lower among women who had breastfed multiple children. Mean serum PCB 138, 153, and 180 concentrations were 11.8, 15.2, and 10.1ng/g lipid, respectively, for women 35-44 years who had breastfed six children and 22.7, 31.9, and 22.5ng/g lipid, respectively, for women 35-44 years who had breastfed only one child. The results tend to support the long-standing hypothesis that depuration of PCBs may occur via breastfeeding.


Assuntos
Aleitamento Materno , Bifenilos Policlorados/sangue , Adolescente , Adulto , Exposição Ambiental/análise , Feminino , Humanos , Inquéritos Nutricionais , Estados Unidos , Adulto Jovem
3.
Crit Rev Toxicol ; 44(7): 600-17, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25068490

RESUMO

Lipophilic persistent environmental chemicals (LPECs) have the potential to accumulate within a woman's body lipids over the course of many years prior to pregnancy, to partition into human milk, and to transfer to infants upon breastfeeding. As a result of this accumulation and partitioning, a breastfeeding infant's intake of these LPECs may be much greater than his/her mother's average daily exposure. Because the developmental period sets the stage for lifelong health, it is important to be able to accurately assess chemical exposures in early life. In many cases, current human health risk assessment methods do not account for differences between maternal and infant exposures to LPECs or for lifestage-specific effects of exposure to these chemicals. Because of their persistence and accumulation in body lipids and partitioning into breast milk, LPECs present unique challenges for each component of the human health risk assessment process, including hazard identification, dose-response assessment, and exposure assessment. Specific biological modeling approaches are available to support both dose-response and exposure assessment for lactational exposures to LPECs. Yet, lack of data limits the application of these approaches. The goal of this review is to outline the available approaches and to identify key issues that, if addressed, could improve efforts to apply these approaches to risk assessment of lactational exposure to these chemicals.


Assuntos
Poluentes Ambientais/análise , Exposição Materna , Leite Humano/química , Medição de Risco , Animais , Relação Dose-Resposta a Droga , Feminino , Humanos , Modelos Teóricos , Método de Monte Carlo , Gravidez , Ratos , Projetos de Pesquisa
4.
Sci Total Environ ; 7762021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-36590071

RESUMO

Exposure to polychlorinated biphenyls (PCBs) can occur through multiple routes and sources, including dietary intake, inhalation, dermal contact, and ingestion of dust and soils. Dietary exposure to PCBs is often considered the primary exposure route for the general population; however, recent studies suggest an increasing contribution from indoor inhalation exposure. Here, we aim to estimate the relative contribution of different PCB exposure pathways for the general population, as well as for select age groups. We conducted a targeted literature review of PCB concentrations in environmental media, including indoor and outdoor air, indoor dust, and soils, as well as of total dietary intake. Using the average concentrations from the studies identified, we estimated PCB exposure through different routes for the general population. In addition, we assessed exposure via environmental media for select age groups. We identified a total of 70 studies, 64 that provided background PCB concentrations for one or more of the environmental media of interest and 6 studies that provided estimates of dietary intake. Using estimates from studies conducted worldwide, for the general population, dietary intake of PCBs was the major exposure pathway. In general, our review identifies important limitations in the data available to assess population exposures, highlighting the need for more current and population-based estimates of PCB exposure, particularly for indoor air and dietary intake.

5.
Environ Health Perspect ; 123(2): 109-13, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25302536

RESUMO

BACKGROUND: Indoor air concentrations of polychlorinated biphenyls (PCBs) in some buildings are one or more orders of magnitude higher than background levels. In response to this, efforts have been made to assess the potential health risk posed by inhaled PCBs. These efforts are hindered by uncertainties related to the characterization and assessment of source, exposure, and exposure-response. OBJECTIVES: We briefly describe some common sources of PCBs in indoor air and estimate the contribution of inhalation exposure to total PCB exposure for select age groups. Next, we identify critical areas of research needed to improve assessment of exposure and exposure response for inhaled PCBs. DISCUSSION: Although the manufacture of PCBs was banned in the United States in 1979, many buildings constructed before then still contain potential sources of indoor air PCB contamination. In some indoor settings and for some age groups, inhalation may contribute more to total PCB exposure than any other route of exposure. PCB exposure has been associated with human health effects, but data specific to the inhalation route are scarce. To support exposure-response assessment, it is critical that future investigations of the health impacts of PCB inhalation carefully consider certain aspects of study design, including characterization of the PCB mixture present. CONCLUSIONS: In certain contexts, inhalation exposure to PCBs may contribute more to total PCB exposure than previously assumed. New epidemiological and toxicological studies addressing the potential health impacts of inhaled PCBs may be useful for quantifying exposure-response relationships and evaluating risks.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Exposição por Inalação/estatística & dados numéricos , Bifenilos Policlorados/análise , Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Humanos , Exposição por Inalação/análise , Projetos de Pesquisa , Medição de Risco/métodos , Incerteza , Estados Unidos
6.
J Expo Sci Environ Epidemiol ; 24(3): 233-43, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23611905

RESUMO

Efforts to compile and standardize human exposure factors have resulted in the development of a variety of resources available to the scientific community. For example, the US Environmental Protection Agency (EPA) developed the Exposure Factors Handbook and Child-specific Exposure Factors Handbook to promote consistency among its various exposure-assessment activities. The US EPA handbooks are compilations of human exposure factors data, including anthropometric and sociocultural data (e.g., body weights, skin-surface areas, and life expectancy), behavioral data (e.g., non-dietary ingestion rates, activity/time use patterns, and consumer product use), factors that may be influenced by the physiological needs of the body, metabolic activity, and health and weight status (e.g., water and food intake, and inhalation rates), and other factors (e.g., building characteristics). Other countries have engaged in similar efforts to compile and standardize exposure factors for use in exposure and risk assessments. For example, the ExpoFacts database contains data for 30 European Union countries. Australia, Canada, Japan, Korea, and Taiwan have developed, or are developing, documents that provide exposure factors data relevant to their populations. The purpose of this paper is to provide an overview of some of the available exposure factors resources; to explore some of the similarities and differences between the US EPA Exposure Factors Handbook and selected other international resources, and to highlight data gaps and present some considerations for promoting consistency among these resources.


Assuntos
Exposição Ambiental , Manuais como Assunto , Internacionalidade , Estados Unidos , United States Environmental Protection Agency
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