Inhalation exposure to semi-volatile polychlorobiphenyls (PCBs) that ubiquitously exist in the environment has the potential to cause adverse health effects. Recently identified sources of airborne PCBs, especially non-legacy sources, stress the importance of risk assessment for inhalation exposure. However, the fate of inhaled airborne PCBs in biological systems and the resultant toxicity remain unexplored. The objective of this thesis research was to investigate the distribution and elimination of semi-volatile PCBs in biological systems after inhalation exposure and evaluate the biologic and toxicologic consequences. This objective was achieved by conducting the following inhalation studies in rats: a short-term exposure study of the body burden and elimination; a subchronic exposure toxicity study; an acute exposure study of PCB11 metabolism; and a mass balance study of [14C]PCB11 following lung exposure. PCBs found in technical Aroclor mixtures and PCB11 were readily absorbed and distributed following nose-only inhalation exposure. PCBs accumulated in adipose tissue, but decayed in other tissues with biological half-lives of several hours. Their elimination was dependent on the structure of the PCB congeners and the metabolic nature of the organ. Lower-chlorinated PCBs exhibited more rapid clearance than higher-chlorinated congeners yet differential rates of elimination were also seen within the homologue. A distinct congener pattern was found in tissues, ranging from tri- to pentachorobiphenyls after subacute and subchronic exposure. Rapid elimination of PCB11 and its metabolite, 4-OH-CB11, were detected in liver following nose-only inhalation exposure by our established methodology. Further investigation revealed that [14C]PCB11 was 99.8% absorbed in lung. Elimination of the [14C]PCB11 and products consisted of an initial fast phase followed by a slow clearance phase. [14C]PCB11 underwent rapid and extensive metabolism in liver. The major products were phase II metabolites which dominated in the non-adipose tissues and were eliminated via the large intestine and urine. Overall, differential congener elimination was found after inhalation of airborne PCBs, with minimal toxicity. Lower-chlorinated congeners were rapidly and extensively metabolized to phase II products and eliminated within hours.

Thesis (M.S.)--University of South Florida, 2007. / Title from PDF of title page. Document formatted into pages; contains 34 pages. Includes bibliographical references.

Thesis (M.S.)--University of Toledo, 2006. / "In partial fulfillment of the requirements for the degree of Master of Science in Occupational Health." Major advisor: Sheryl Milz. Includes abstract. Document formatted into pages: iv, 66 p. Title from title page of PDF document. Title at ETD Web site: Advantages of using the ANSI/ASHRAE 110-1995 tracer gas test method versus the ANSI/AIHA Z9.5-1992 face velocity test method for chemical laboratory hood certification. Bibliography: pages 58-61.

Introdução: surtos de asma, por poeira da soja, têm sido relatados, havendo casos fatais. Objetivo: correlacionar exposição, sensibilização e alergia respiratória a esta, no Brasil. Métodos: 590 voluntários (testes de punctura e dosagem de IgE específica). Resultados: operários da indústria apresentaram 15% de. sensibilização à soja. Caminhoneiros 22%. Moradores no entorno da indústria 22% enquanto aqueles que residem distantes 6%. .Na região agrícola distante das plantações 13% e em meio à soja 28% com 5% de sensibilizados somente à soja. O percentual de IgE positivas para soja foi 16%. Houve marcante sensibilização aos fungos. Conclusão: A prevalência de sensibilização à soja demonstra o impacto desse tipo de poluição. A sensibilização aos fungos que colonizam a soja estocada não deve ser subestimada / Background: Asthma outbreaks, by soybean dust inhalation, have been reported fatal cases.. Objective: To correlate exposure and sensitization to soybean dust in Brazil.. Methods: 590 volunteers exposed to soy dust. Prick skin tests were performed and specific IgE were measured in sera.. Results: the workers from the oil refinery had sensitization to soy (15%). Truck drivers 22%. Industry neighborhood 22%. and people who live far from this place presented only 6%. People from agricultural area far from the soy plantations 13% and in the middle of the soy 28%.with 5% sensitized only by soybean . Positive IgE was 16 %. Conclusion: a high prevalence of sensitivity to soybean hull demonstrates the impact of this kind of pollution. The sensitization to the fungi which colonize soybean storage can not be underestimated

O Hexaclorociclohexano (HCH) é um inseticida do grupo dos organoclorados, composto por uma mistura de isômeros formados durante a síntese química, através de sucessivas adições de cloro ao benzeno. Estes isômeros podem contaminar não só o meio ambiente como também a população que tenha contato direto ou indireto com os resíduos. Nas décadas de 70 e 80, foi utilizado um produto comercial composto pelo ativo HCH comercializado como \"Hexabel®\" no controle de insetos xilófagos no Acervo Histórico de Joinville em Santa Catarina. A aplicação do inseticida foi realizada pelos próprios funcionários do Arquivo Histórico, e houve intensa manipulação dos documentos tratados durante uma mudança do prédio o presente trabalho teve como objetivo validar uma metodologia de determinação de resíduos do HCH e seus isômeros em soro sangüíneo, e analisar o grau de exposição dos funcionários e ex-funcionários do Arquivo Histórico de Joinville ao produto. Foram realizados exames sorológicos em todos os funcionários e ex - funcionários do local e também na população que sabidamente nunca tiveram contato com o ativo, denominada população controle. As análises foram realizadas após a validação do método multiresíduos que obtém todos os ativos em uma única extração e tem detecção por Cromatografia a gás com detector de captura (GC-ECD) de elétrons. Os resultados comprovaram comprovaram a eficiência do método, através de dados em conformidade com os critérios do ensaio. Os resultados obtidos no estudo da população mostraram que a quantidade de HCH no soro sangüíneo de funcionários, ex-funcionários e da população controle estão abaixo do limite de quantificação de 0,04μg dL-1 para Alfa HCH e Gama HCH \"Lindana\" e 0,08μg dL-1 para Beta e Delta HCH. / Hexachlorcyciohexane (HCH) is an organochloride insecticide formed by a mixture of chemical isomers produced during its chemical synthesis, obtained after successive inserts of chlorine atoms on benzene molecule. These isomers may contaminate both the environment and the people who had direct or indirect contact with the HCH residues. On 70\'s and 80\'s, its was used a commercial product which contained HCH on its formula and was commercialized as Hexabel®. The product was used to control the xylophage insect population on the Historical Archieve of Joinville, at Santa Catarina, Brazil. The own employees did the insecticide application and there was an intensive manipulation of the treated material during a building change. The objective of this work was to validate a methodology to quantify the HCH residues and its isomers on blood plasma and analyze the employee\'s exposure extent to the chemical. It was done serological investigation on employees, former-employees and on non-exposed people, which was classified as the control population. The analyses were done after the methodology validation. The method was capable to obtain all isomers on a unique extraction and the detection and quantification were done by gas chromatography with electron-capture detector (GC-ECD). The results obtained showed that the proposed method is accurate, and that the amount of HCH residues on blood plasma of all individuals analyzed was lower than the quantification limits established to the method, which were 0,04 μg dL-1 for the alpha- and gamma- HCH (lindana) and 0,08 μg dL-1 for the beta- and delta- HCH.

Background : Atrazine is an agricultural herbicide used extensively in corn production worldwide. Atrazine is an endocrine disruptor and has been linked to many other deleterious health outcomes. Exposure assessment studies have been carried out in Iowa among farm and non-farm populations. However, commercial pesticide applicators have been left out of those studies. Atrazine is also used in developing countries in grain production. In developing countries there is great concern about acute pesticide poisonings, but chronic exposure to less acutely toxic pesticides has not been studied extensively. This study assessed the in-home contamination of atrazine among commercial pesticide applicators in Iowa and then quantitatively analyzed these results with results from similar studies. Occupational inhalation exposure to atrazine was also assessed in Honduras. Methods : Dust samples were taken from 29 commercial pesticide applicator households in four different locations. This sampling was done once during the atrazine application season and again six months later during winter months to assess atrazine persistence. Occupational and household characteristics were analyzed for associations with atrazine dust levels. Data from two previous studies that analyzed farm and non-farm household dust samples for atrazine were combined with data from the commercial applicator's homes. This new and larger dataset was analyzed to identify which population has the greatest risk for take-home atrazine exposure and what determinants were associated with in-home atrazine dust levels. Lastly, corn production practices in Honduras were evaluated and personal air samples were taken from pesticide applicators during atrazine application to assess inhalation exposure. Results : The first study found that atrazine levels persist into the winter months in the homes of commercial applicators. Atrazine handling (days, pounds, and acres sprayed) were all positively associated with in-home atrazine levels. Commercial applicators that change their shoes inside had higher atrazine levels. More frequent floor cleaning was associated with lower atrazine levels. The second study identified commercial applicators' homes as the most contaminated compared with farmers who apply atrazine to their own land, farmers who hire out atrazine application, and non-farm homes. Farmers that apply their own atrazine also had significantly higher atrazine levels in their homes. The association between atrazine handling and household atrazine levels was highly significant in this study (p < 0.001). In Honduras, atrazine is applied to corn fields with tractor/boom equipment and manual backpack sprayers. Despite applying about one-fifteenth the amount of atrazine, backpack sprayers are exposed to nearly equal amounts of atrazine via inhalation exposure and likely have greater exposure via the dermal route. Among backpack sprayers, which type of spray nozzle used is associated with inhalation exposure. Among tractor/boom applicators, tractor drivers have much lower inhalation exposure than workers who operate and observe the boom. Conclusions : The amount of atrazine handled is the most important determinant for predicting in-home atrazine levels in Iowa. Ubiquitous atrazine contamination and its distribution within homes and among household type provide strong evidence for the take-home pathway. While some improvements have been made in Honduras regarding pesticide application, poor farm workers and small farmers still use antiquated pesticide application techniques which leads to a higher risk of inhalation and dermal exposure.

Polychlorinated biphenyls (PCBs) are a group of 209 persistent organic pollutants, whose documented carcinogenic, neurological and respiratory toxicities are expansive and growing. Existing inhalation estimates demonstrate ubiquitous exposure to World Health Organization (WHO) indicator PCBs and limited other PCB congeners in North America and Europe. However, inhalation exposure estimates of most lower-chlorinated congeners are lacking, and continuing release of PCBs from urban areas demands location-specific assessments of PCB exposure in ambient air and contaminated environments. Using paired indoor and outdoor airborne PCB measurements and activity questionnaires from the AESOP Study, we assess congener-specific exposure rates for adolescent children and their mothers in East Chicago, Indiana and Columbus Junction, Iowa. Our cohorts of 129 (EC) and 135 (CJ) and our detection of 202 individual congeners and coelutions allows unprecedented quantification of congener-specific inhalation exposure, which we compare to dietary exposure using Total Diet Survey PCB concentrations. ∑PCB inhalation is greater for children than for their mothers in both locations, and is greater for East Chicago mothers and children than for Columbus Junction mothers and children, respectively. Schools attended by AESOP Study children have higher indoor PCB concentrations than do homes, and contribute to more than half of children's inhalation PCB exposure. Inhalation of the potentially neurotoxic congeners PCB 11, 40/41/71, and 51 was apparent among individuals at each location. Additional, congener-specific and biological inferences are possible via comparison with sera-based PCB concentrations for these cohorts.

Semi-volatile lower chlorinated PCBs (LC-PCBs), comprised of mostly tetra or lower chlorinated congeners, are detected in old buildings and outdoors in high concentrations. PCBs cause endocrine disruption, neurotoxicity and many other adverse effects, and are human carcinogens. Epidemiological studies so far have relied upon serum concentrations of PCBs or OH-PCBs as markers of exposure. Despite the detection of LC-PCBs in high levels in buildings and other environments, only a few studies have reported LC-PCBs in human serum. One of the reasons for low serum detection of LC-PCBs could be the further biotransformation and excretion of OH-PCBs from the body. Therefore, the objective of this dissertation research was to study the metabolism of one of the LC-PCBs in rats and to identify a suitable metabolite marker of inhalation exposure for a future epidemiological study in humans. We chose PCB3 (4-chlorobiphenyl), a mono chlorinated PCB found in high concentrations in many buildings, as a model to study the metabolism. The first aim was to identify final metabolites of PCB3 in vivo. Male Sprague-Dawley rats were held in metabolism cages following exposure to PCB3 via i.p. injection. Blood, urine and feces were collected, and an analytical method for extraction of PCB3 metabolites was developed. By identifying the metabolites by LC/MS, a complete biotransformation pathway for PCB3 was elucidated. Major urinary metabolites of PCB3 were sulfates and mercapturates, while glucuronides and free phenolic forms were minor. The second aim was to study the disposition and toxicity of phenolic and sulfate metabolites after inhalation exposure to PCB3 in female Sprague-Dawley rats. Airborne PCB3 vapor was generated in a flask and passed through an inhalation exposure system, where rats were exposed via nose-only inhalation. Both hydroxylated and sulfated metabolites were detected in serum, liver, lungs, and brain. The serum clearance half-lives of these metabolites were less than two hours. Serum chemistry parameters were similar in PCB3 exposed and control rats. As a marker of bioactivation of PCB3 to electrophilic species, 8-oxo-dG was quantified in urine, but the difference was not statistically significant between control and exposed rats. The third aim was to study the routes of excretion of metabolites after inhalation to airborne PCB3. Bile cannulated and intact rats were exposed to PCB3 via nose only inhalation. Metabolites detected in bile were mostly sulfates and some glucuronide. Fecal metabolites were exclusively phenols despite very low concentration of free phenolic forms in bile. Peak excretion of metabolites in feces and urine occurred within 24 h, and over sixty percent of the dose was recovered within 24 h. The major route of excretion of PCB3 was urine in the form of sulfated metabolites. Sulfated metabolites were stable in urine for a month without aid of any preservatives. This dissertation shows that PCB3 is rapidly metabolized to phenols and conjugated mostly to sulfates. Conjugated metabolites, elaborated into bile, are either reabsorbed or hydrolyzed in the gut and excreted in feces as phenolic forms. Serum concentrations of sulfates are higher than free phenolic forms at any time after exposure, and are also detected in lungs and brain. PCB3 sulfates are stable metabolites and can serve as a metabolite marker of inhalation exposure to PCB3.

Thesis--University of Oklahoma. / Bibliography: leaves 137-141.

p-Dichlorobenzene (p-DCB) and naphthalene are compounds classified as Group C carcinogens according to the USEPA. Sources of p-DCB and naphthalene include moth repellents and deodorizers typically used in closets, garment bags, and toilet bowls found in pure form. In this study, laboratory, closet, and garment bag experiments were used to determine emission rates of p-DCB and naphthalene from consumer products (closet air freshener, toilet bowl deodorizer, and moth repellent). Emission rates varied considerably between products that contain p-DCB, primarily due to product packaging, and were generally suppressed when the product was used in a closed closet or garments bag, relative to products placed in well-ventilated chambers. Experimental mass emission rates were used in conjunction with a well-mixed reactor model to predict indoor p-DCB and naphthalene concentrations for a range of reasonable residential scenarios. Results suggest that exposures under worst-case scenarios could lead to excess lifetime cancer risks of greater than 20,000 in a million (2%) for those who use consumer products that are pure p-DCB, a risk that dwarfs any reported environmental cancer risks over large segments of the US population. Since such products are typically used where clothing is kept, significant chemical adsorption onto clothing is possible following sublimation from the solid product. Chamber experiments were used to determine the amount of p-DCB and naphthalene mass that adsorbs onto selected clothing materials made of cotton, polyester, or wool. Cloth specimens were kept inside a chamber through which an air stream containing p-DCB or naphthalene was passed for one month. After this time, p-DCB or naphthalene were chemically extracted from the cloth specimens. Polyester was determined to be the most adsorbent material, while cotton was the least adsorbent for each chemical. Equilibrium partition coefficients of 0.01 m³/g for p-DCB and 0.02 m³/g for naphthalene were determined experimentally for wool. Desorption rates were determined in both laboratory chambers and a closet in a test house. Results suggest prolonged persistence of p-DCB and naphthalene on polyester and wool, e.g., half-lives of 12 to 20 days after a moth repellent is removed from the clothes storage environment. An exposure scenario was also carried out to compare the inhalation and dermal exposure risks associated with contaminated clothing. / text