Volatile chemical emissions from fragranced baby products

Fragranced consumer products have been associated with adverse effects on human health. Babies are exposed to a variety of fragranced consumer products, which can emit numerous volatile organic compounds (VOCs), some considered potentially hazardous. However, fragranced baby products are exempt from disclosure of all ingredients. Consequently, parents and the public have little information on product emissions. This study investigates VOCs emitted from a range of fragranced baby products, including baby hair shampoos, body washes, lotions, creams, ointments, oils, hair sprays, and fragrance. The products were analysed using gas chromatography/mass spectrometry (GC/MS) headspace analysis. Of the 42 baby products tested, 21 products made claims of green, organic, or all-natural. Results of the analysis found 684 VOCs emitted collectively from the 42 products, representing 228 different VOCs. Of these 684 VOCs, 207 are classified as potentially hazardous under federal regulations, representing 43 different VOCs. The most common VOCs emitted were limonene, acetaldehyde, ethanol, alpha-pinene, linalool, beta-myrcene, acetone, and beta-pinene. A comparison between ingredients emitted and ingredients listed reveals that only 5% of the 684 VOCs, including 12% of 207 potentially hazardous VOCs, were listed on the product label, safety data sheet, or website. More than 95% of both green and regular products emitted one or more potentially hazardous VOCs. Further, emissions of the most prevalent VOCs from green, organic, or all-natural products were not significantly different from regular products. Results from this study can help improve public awareness about emissions from baby products, with the aim to reduce pollutant exposure and potential adverse effects on babies.     

Fragranced consumer products: effects on asthmatics

Fragranced consumer products, such as cleaning supplies, air fresheners, and personal care products, can emit a range of air pollutants and trigger adverse health effects. This study investigates the prevalence and types of effects of fragranced products on asthmatics in the American population. Using a nationally representative sample (n?=?1137), data were collected with an on-line survey of adults in the USA, of which 26.8% responded as being medically diagnosed with asthma or an asthma-like condition. Results indicate that 64.3% of asthmatics report one or more types of adverse health effects from fragranced products, including respiratory problems (43.3%), migraine headaches (28.2%), and asthma attacks (27.9%). Overall, asthmatics were more likely to experience adverse health effects from fragranced products than non-asthmatics (prevalence odds ratio [POR] 5.76; 95% confidence interval [CI] 4.34–7.64). In particular, 41.0% of asthmatics report health problems from air fresheners or deodorizers, 28.9% from scented laundry products coming from a dryer vent, 42.3% from being in a room cleaned with scented products, and 46.2% from being near someone wearing a fragranced product. Of these effects, 62.8% would be considered disabling under the definition of the Americans with Disabilities Act. Yet 99.3% of asthmatics are exposed to fragranced products at least once a week. Also, 36.7% cannot use a public restroom if it has an air freshener or deodorizer, and 39.7% would enter a business but then leave as quickly as possible due to air fresheners or some fragranced product. Further, 35.4% of asthmatics have lost workdays or a job, in the past year, due to fragranced product exposure in the workplace. More than twice as many asthmatics would prefer that workplaces, health care facilities and health care professionals, hotels, and airplanes were fragrance-free rather than fragranced. Results from this study point to relatively simple and cost-effective ways to reduce exposure to air pollutants and health risks for asthmatics by reducing their exposure to fragranced products.     

Fragranced consumer products: exposures and effects from emissions

Fragranced consumer products, such as cleaning supplies, air fresheners, and personal care products, are a primary source of indoor air pollutants and personal exposure. Previous research indicates that fragranced products can trigger adverse health effects, with implications for workplaces and public places. This is the first study to examine the multiple dimensions of exposures related to fragranced products and effects in the US population. The study investigated the prevalence and types of fragranced product exposures, associated health effects, awareness of product emissions, and preferences for fragrance-free policies and environments. Data were collected using an online survey with a nationally representative population (n = 1136) of adults in the USA. Overall, 34.7 % of the population reported health problems, such as migraine headaches and respiratory difficulties, when exposed to fragranced products. Further, 15.1 % have lost workdays or a job due to fragranced product exposure in the workplace. Also, 20.2 % would enter a business but then leave as quickly as possible if they smell air fresheners or some fragranced product. Over 50 % of the population would prefer that workplaces, health care facilities and professionals, hotels, and airplanes were fragrance-free. While prior research found that common fragranced products, even those called green and organic, emitted hazardous air pollutants, more than two thirds of the population were not aware of this, and over 60 % would not continue to use a fragranced product if they knew it emitted such pollutants. Results from this study provide strong evidence that fragranced products can trigger adverse health effects in the general population. The study also indicates that reducing exposure to fragranced products, such as through fragrance-free policies, can provide cost-effective and relatively simple ways to reduce risks and improve air quality and health.     

Fragranced consumer products: sources of emissions,exposures, and health effects in the UK

Common in society, fragranced consumer products such as cleaning supplies and air fresheners are a primary source of volatile emissions that contribute to pollutants indoors and to personal exposure. Further, fragranced products have been associated with adverse health effects. This study investigates the sources of emissions, human exposures, and health and societal impacts from fragranced consumer products in the United Kingdom (UK). It examines the prevalence and types of fragranced product use, associated health effects, exposure situations, awareness of product emissions, and preferences for fragrance-free policies and indoor environments. Using a nationally representative population sample (n?=?1100), data were collected in June 2016 using an online survey of adults in the UK, comprising England, Wales, Northern Ireland, and Scotland. Across the UK population, 27.8% report health problems, such as migraine headaches (8.4%) and asthma attacks (6.8%), when exposed to fragranced products. Yet 99.3% of the population are exposed to fragranced products at least once a week. When given a choice, more people would prefer that workplaces, health care facilities and professionals, hotels, and airplanes were fragrance-free rather than fragranced. Although fragranced products, even ones called green and organic, can emit potentially hazardous yet undisclosed pollutants, 75.0% of the population were not aware of this, and more than half would stop using their product if they knew it emitted such pollutants. This study provides important evidence that the UK population is regularly exposed to fragranced products, that these exposures are associated with adverse and often serious health effects, and that the public is largely unaware of their potential exposures. While more research is needed, reducing exposure to fragranced products, such as through fragrance-free policies, can provide an immediate step to reduce health risks and improve air quality.     

Fragranced consumer products: effects on autistic adults in the United States,Australia, and United Kingdom

Fragranced consumer products, such as cleaning supplies, air fresheners, and personal care products, can have adverse effects on both air quality and health. This study investigates the effects of fragranced products on autistic individuals ages 18–65 in the United States, Australia, and United Kingdom. Nationally representative population surveys (n?=?1137; 1098; 1100) found that, across the three countries, 4.3% of adults (n?=?142) report medically diagnosed autism (2.3%), an autism spectrum disorder (2.4%), or both. Of these autistic adults, 83.7% report adverse health effects from fragranced products, including migraine headaches (42.9%), neurological problems (34.3%), respiratory problems (44.7%), and asthma attacks (35.9%). In particular, 62.9% of autistic adults report health problems from air fresheners or deodorizers, 57.5% from the scent of laundry products coming from a dryer vent, 65.9% from being in a room cleaned with scented products, and 60.5% from being near someone wearing a fragranced product. Health problems can be severe, with 74.1% of these effects considered potentially disabling under legislation in each country. Further, 59.4% of autistic adults have lost workdays or lost a job, in the past year, due to fragranced product exposure in the workplace. More than twice as many autistic as well as non-autistic individuals would prefer that workplaces, health care facilities, and health care professionals were fragrance-free rather than fragranced. Results show that vulnerable individuals, such as those with autism or autism spectrum disorders, can be profoundly, adversely, and disproportionately affected by exposure to fragranced consumer products.     

Assessing exposure to air toxics relative to asthma

Asthma is a respiratory disease whose prevalence has been increasing since the mid 1970s and that affects more than 14.6 million residents of the United States. Environmental triggers of asthma include air pollutants that are respiratory irritants. Air toxics emitted into the ambient air are listed in the 1990 Clean Air Act Amendments as hazardous air pollutants (HAPs) if they can adversely affect human health, including the respiratory tract. HAPs include particulate and gaseous-phase pollutants, individual organic compounds and metals, and mixtures. Associations between asthma exacerbation and both particles and indoor volatile organic compounds (VOCs), often referred to as indoor air quality, have been reported. Studies conducted in the United States, Canada, and Europe over the past two decades have shown that most people living in the developed countries spend the majority of their time indoors and that the air concentrations of many air toxics or HAPs are higher indoors than in the ambient air in urban, suburban, and rural settings. Elevated indoor air concentrations result from emissions of air toxics from consumer products, household furnishings, and personal activities. The Relationship of Indoor, Outdoor and Personal Air (RIOPA) study was designed to oversample homes in close proximity to ambient sources, excluding residences where smokers lived, to determine the contribution of ambient emissions to air toxics exposure. The ratios of indoor to outdoor air concentrations of some VOCs in homes measured during RIOPA were much greater than one, and for most other VOCs that had indoor-to-outdoor ratios close to unity in the majority of homes, elevated ratios were found in the paired samples with the highest concentration. Thus, although ambient emissions contribute to exposure of some air toxics indoors as well as outdoors, this was not true for all of the air toxics and especially for the higher end of exposures to most volatile organic air toxics examined. It is therefore critical, when evaluating potential effects of air toxics on asthma or other adverse health end points, to determine where the exposure occurs and the source contributions for each air toxic and target population separately and not to rely solely on ambient air concentration measurements.     

Exposures and effects from fragranced consumer products in Sweden

Fragranced consumer products—such as cleaning supplies, perfume, and air fresheners—have been associated with indoor air pollutants and adverse human health effects. Through a nationally representative population-based survey, this study investigates sources and risks associated with exposure to fragranced consumer products in Sweden. It examines the frequency and types of fragranced product use, associated health effects, exposure situations, knowledge of product emissions, and preferences for fragrance-free policies and indoor environments. Data were collected in July 2017 using an online survey of adults (n?=?1100), representative of age, gender, and region in Sweden. Across the Swedish population, 33.1% report health problems, such as respiratory difficulties (20.0%), migraine headaches (16.1%), and asthma attacks (5.5%), when exposed to fragranced products. Of these reports, 24.2% could be considered potentially disabling. While 98.5% use fragranced products at least once a week, 70.9% were unaware that fragranced products, even ones called green and organic, can emit potentially hazardous air pollutants. Importantly, 6.7% of the population lost workdays or a job, in the past year, due to exposure to fragranced products in the workplace. Also, 18.1% enter and then leave a business as quickly as possible due to air fresheners or a fragranced product. A strong majority of the population would prefer that workplaces, health care facilities and professionals, airplanes, and hotels were fragrance-free rather than fragranced. Results from this study provide new and important evidence that exposure to fragranced consumer products is pervasive in Sweden, that these exposures are associated with adverse health and societal effects, and that reducing exposures such as through fragrance-free policies can provide benefits to air quality and public health.     

Modeling population exposures to outdoor sources of hazardous air pollutants

Accurate assessment of human exposures is an important part of environmental health effects research. However, most air pollution epidemiology studies rely upon imperfect surrogates of personal exposures, such as information based on available central-site outdoor concentration monitoring or modeling data. In this paper, we examine the limitations of using outdoor concentration predictions instead of modeled personal exposures for over 30 gaseous and particulate hazardous air pollutants (HAPs) in the US. The analysis uses the results from an air quality dispersion model (the ASPEN or Assessment System for Population Exposure Nationwide model) and an inhalation exposure model (the HAPEM or Hazardous Air Pollutant Exposure Model, Version 5), applied by the US. Environmental protection Agency during the 1999 National Air Toxic Assessment (NATA) in the US. Our results show that the total predicted chronic exposure concentrations of outdoor HAPs from all sources are lower than the modeled ambient concentrations by about 20% on average for most gaseous HAPs and by about 60% on average for most particulate HAPs (mainly, due to the exclusion of indoor sources from our modeling analysis and lower infiltration of particles indoors). On the other hand, the HAPEM/ASPEN concentration ratio averages for onroad mobile source exposures were found to be greater than 1 (around 1.20) for most mobile-source related HAPs (e.g. 1, 3-butadiene, acetaldehyde, benzene, formaldehyde) reflecting the importance of near-roadway and commuting environments on personal exposures to HAPs. The distribution of the ratios of personal to ambient concentrations was found to be skewed for a number of the VOCs and reactive HAPs associated with major source emissions, indicating the importance of personal mobility factors. We conclude that the increase in personal exposures from the corresponding predicted ambient levels tends to occur near locations where there are either major emission sources of HAPs or when individuals are exposed to either on- or nonroad sources of HAPs during their daily activities. These findings underscore the importance of applying exposure-modeling methods, which incorporate information on time-activity, commuting, and exposure factors data, for the purposes of assigning exposures in air pollution health studies.     

Volatile chemical emissions from essential oils

Essential oils, widely used in society, emit numerous volatile organic compounds (VOCs). Some of these VOCs are considered as potentially hazardous under federal regulations. However, essential oils are exempt from disclosure of their ingredients on their label. Thus, the public may lack information on emissions and potential hazards from essential oils. This study examined VOCs emitted from a range of commercial essential oils, including tea tree oils, lavender oils, eucalyptus oils, and other individual oils and mixtures of oils. Using headspace gas chromatography/mass spectrometry (GC/MS), the study analyzed 24 commercial essential oils, including 12 with claims of being “natural” or related terms, such as organic, 100% pure, or plant-based. Results identified 595 VOCs emitted from the 24 essential oils, representing 188 different VOCs. The most common VOCs emitted were alpha-pinene, limonene, acetone, linalool, alpha-phellandrene, beta-myrcene, and camphene. Among the 589 VOCs identified, 124 VOCs, representing 33 different VOCs, are classified as potentially hazardous. All natural and regular essential oils emitted one or more potentially hazardous VOCs, such as acetaldehyde, acetone, and ethanol. Toluene was also found in 50% of essential oils. Moreover, for the prevalent VOCs classified as potentially hazardous, no significant difference was found between regular and natural essential oils. This study provides insights and information about emissions of commercial essential oils that can be useful for public awareness and risk reduction.     

Measurement of secondary products during oxidation reactions of terpenes and ozone based on the PTR-MS analysis: effects of coexistent carbonyl compounds

Continuous measurements using proton transfer reaction mass spectrometry (PTR-MS) can be used to describe the production processes of secondary products during ozone induced oxidation of terpenes. Terpenes are emitted from woody building materials, and ozone is generated from ozone air purifiers and copy machines in indoor environments. Carbonyl compounds (CCs) are emitted by human activities such as smoking and drinking alcohol. Moreover, CCs are generated during ozone oxidation of terpenes. Therefore, coexistent CCs should affect the ozone oxidation. This study has focused on the measurement of secondary products during the ozone oxidation of terpenes based on the use of PTR-MS analysis and effects of coexistent CCs on oxidized products. Experiments were performed in a fluoroplastic bag containing α-pinene or limonene as terpenes, ozone and acetaldehyde or formaldehyde as coexistent CCs adjusted to predetermined concentrations. Continuous measurements by PTR-MS were conducted after mixing of terpenes, ozone and CCs, and time changes of volatile organic compounds (VOCs) concentrations were monitored. Results showed that, high-molecular weight intermediates disappeared gradually with elapsed time, though the production of high-molecular weight intermediates was observed at the beginning. This phenomenon suggested that the ozone oxidation of terpenes generated ultrafine particles. Coexistent CCs affected the ozone oxidation of α-pinene more than limonene.     

Fragranced consumer products: effects on asthmatic Australians

Exposure to fragranced consumer products, such as air fresheners and cleaning supplies, is associated with adverse health effects such as asthma attacks, breathing difficulties, and migraine headaches. This study investigated the prevalence and types of health problems associated with exposure to fragranced products among asthmatic Australians. Nationally representative cross-sectional data were obtained in June 2016 with an online survey of adult Australians (n?=?1098), of which 28.5% were medically diagnosed with asthma or an asthma-like condition. Nationally, 55.6% of asthmatics, and 23.9% of non-asthmatics, report adverse health effects after exposure to fragranced products. Specifically, 24.0% of asthmatics report an asthma attack. Moreover, 18.2% of asthmatics lost workdays or a job in the past year due to fragranced products in the workplace. Over 20% of asthmatics are unable to access public places and restrooms that use air fresheners. Exposure to fragranced products is associated with health problems, some potentially serious, in an estimated 2.2 million asthmatic adult Australians. Asthmatics were proportionately more affected than non-asthmatics (prevalence odds ratio 3.98; 95% confidence interval 3.01–5.24). Most asthmatics would prefer workplaces, healthcare facilities, and environments that are fragrance-free, which could help reduce adverse effects.     

Low-temperature washing of patients' clothing; effects of detergent with disinfectant and a tunnel drier on bacterial survival

Patients' dresses were washed at 40 degrees C using an ordinary detergent for 1 week and a novel detergent with added 'Triclosan' for the following 2 weeks. The bacterial load on the finished laundry was acceptably low using either detergent. The killing of residual bacteria on washed clothing by drying in a tunnel finisher was demonstrated. This preliminary study did not show any benefits to be gained from the addition of 'Triclosan' to detergent for the low-temperature laundering of patients' clothing.     

Worker exposure to volatile organic compounds in the vehicle repair industry

This study evaluated exposures among vehicle repair technicians to hexane, acetone, toluene, and total volatile organic compounds (VOCs). On randomly selected workdays, we observed a characteristic pattern of solvent use among 36 technicians employed in 10 repair shops, each of which used an aerosol solvent product. We obtained quantitative exposure measurements from a subset of nine technicians (employed in three of these shops) who used an aerosol product containing hexane (25-35%), acetone (45-55%), and toluene (5-10%). The time-weighted average (TWA) exposure concentration for task-length breathing zone (BZ) samples (n = 23) was 36 mg/m(3) for hexane, 50 mg/m(3) for acetone, and 10 mg/m(3) for toluene. The TWA area concentrations (n = 49) obtained contemporaneously with BZ samples ranged from 25% to 35% of the BZ concentrations. The solvent emission rate (grams emitted/task time) was correlated with the total VOC exposure concentration (R(2) = 0.45). The proportions of VOCs in the BZ samples were highly correlated (r = 0.89 to 0.95) and were similar to those of the bulk product. Continuous exposure measurements for total VOCs (n = 1238) during 26 tasks produced a mean BZ VOC "pulse" of 394 mg/m(3) within 1 min following initiation of solvent spraying. The geometric mean air speed was 5.2 meters/min in the work areas (n = 870) and was associated with 0.8 air changes per minute in the BZ. The findings suggest that vehicle repair technicians who use aerosol solvent products experience episodic, inhalation exposures to the VOCs contained in these products, and the proportions of VOCs in the breathing zone are similar to those of the bulk product. Because acetone appears to amplify the severity and duration of the neurotoxic effects of n-hexane, products formulated with both hexane and acetone should be avoided. Further evaluation of exposures to VOCs is needed in this industry, along with information on effective alternatives to aerosol solvent products.     

Hazardous air pollutants and asthma

Asthma has a high prevalence in the United States, and persons with asthma may be at added risk from the adverse effects of hazardous air pollutants (HAPs). Complex mixtures (fine particulate matter and tobacco smoke) have been associated with respiratory symptoms and hospital admissions for asthma. The toxic ingredients of these mixtures are HAPs, but whether ambient HAP exposures can induce asthma remains unclear. Certain HAPs are occupational asthmagens, whereas others may act as adjuncts during sensitization. HAPs may exacerbate asthma because, once sensitized, individuals can respond to remarkably low concentrations, and irritants lower the bronchoconstrictive threshold to respiratory antigens. Adverse responses after ambient exposures to complex mixtures often occur at concentrations below those producing effects in controlled human exposures to a single compound. In addition, certain HAPs that have been associated with asthma in occupational settings may interact with criteria pollutants in ambient air to exacerbate asthma. Based on these observations and past experience with 188 HAPs, a list of 19 compounds that could have the highest impact on the induction or exacerbation of asthma was developed. Nine additional compounds were identified that might exacerbate asthma based on their irritancy, respirability, or ability to react with biological macromolecules. Although the ambient levels of these 28 compounds are largely unknown, estimated exposures from emissions inventories and limited air monitoring suggest that aldehydes (especially acrolein and formaldehyde) and metals (especially nickel and chromium compounds) may have possible health risk indices sufficient for additional attention. Recommendations for research are presented regarding exposure monitoring and evaluation of biologic mechanisms controlling how these substances induce and exacerbate asthma.     

室内材料中挥发性有机物释放模式的研究进展

室内材料中释放的挥发性有机化合物（ＶＯＣｓ）是造成室内空气污染的主要原因之一。ＶＯＣｓ的释放特性是室内空气质量研究的重要组成部分。可精确控制条件的暴露小室技术已成功地用于ＶＯＣｓ释放特性的研究。该技术可用于建立ＶＯＣｓ释放浓度随时间变化的模式，进而也可建立ＶＯＣｓ释放率随时间变化的模式。本文综述了室内材料中挥发性有机化合物的释放模式，阐述了释放过程的基本原理、影响参数和不同释放模式的应用进展。从目前的研究状况来看，单纯挥发模式、稀释模式及蒸汽压模式由于没有考虑到室内普遍存在的吞吐效应的影响，故其应用受到限制。吞吐效应模式是一种比较全面的释放模式，能够较好地描述室内材料中ＶＯＣｓ的释放特性，具有广泛的应用前景。     

Inhalation of hazardous air pollutants from environmental tobacco smoke in US residences

In the United States, 48 million adults smoke 3.5-5 x 10(11) cigarettes/year. Many cigarettes are smoked in private residences, causing regular environmental tobacco smoke (ETS) exposure to roughly 31 million nonsmokers (11% of the US population), including 16 million juveniles. (Upper bound estimates are 53 million exposed nonsmokers including 28 million juveniles.) ETS contains many chemical species whose industrial emissions are regulated by the US federal government as hazardous air pollutants (HAPs). In this paper, average daily residential exposures to and intakes of 16 HAPs in ETS are estimated for US nonsmokers who live with smokers. The evaluation is based on material-balance modeling; utilizes published data on smoking habits, demographics, and housing; and incorporates newly reported exposure-relevant emission factors. The ratio of estimated average exposure concentrations to reference concentrations is close to or greater than one for acrolein, acetaldehyde, 1,3-butadiene, and formaldehyde, indicating potential for concern regarding noncancer health effects from chronic exposures. In addition, lifetime cancer risks from residential ETS exposure are estimated to be substantial ( approximately 2-500 per million) for each of five known or probable human carcinogens: acetaldehyde, formaldehyde, benzene, acrylonitrile, and 1,3-butadiene. Cumulative population intakes from residential ETS are compared for six key compounds against ambient sources of exposure. ETS is found to be a dominant source of environmental inhalation intake for acrylonitrile and 1,3-butadiene. It is an important cause of intake for acetaldehyde, acrolein, and formaldehyde, and a significant contributor to intake for benzene.     

On the release of asbestos fibers from weathered and corroded asbestos cement products

The controversy on whether weathered and corroded asbestos cement products are emitting biologically significant asbestos fiber concentrations in ambient air has not been resolved. Nor is it known if the weathered and corroded asbestos cement products release asbestos fibers which have the same carcinogenic potency as "standard" chrysotile. The purpose of this research project was to develop a method for sampling and measuring asbestos fiber emissions from solid planar surfaces (i.e., roofs and facades) consisting of asbestos cement products and to develop methods for studying the physical and chemical changes and the carcinogenic potency of the emitted fibers. Using this method asbestos fiber emissions in ambient air have been measured in the FRG during 1984/1986. The emissions of asbestos fibers longer than 5 microns were in the range 10(6) to 10(8) fibers/m2.hr. The ambient air concentrations of these asbestos fibers were for the most part less than 10(3) fibers/m3. It was shown that the emitted asbestos fibers were chemically changed and it was shown with animal experiments that their carcinogenic potency did not differ from the carcinogenicity of "standard" chrysotile fibers.     

降低医院被服三件套洗涤成本

目的降低医院被服三件套洗涤成本。方法品管圈活动。结果医院被服三件套洗涤成本为2.64元/套,具有较大改进空间。针对被服洗涤电费成本及洗涤剂成本高,利用头脑风暴、鱼骨图、查检表等确定真因并拟定对策,从安装太阳能系统,扩建晾晒场,优化洗涤工作流程,采用医院专用洗涤剂添加组合等方面实施改进,使被服洗涤成本降低为1.92元/套。     

Decontamination of chemical protective clothing

This study explored decontamination procedures for removing some organic solvents from protective clothing. The permeation experiments were performed on new and decontaminated specimens in seven polymer/chemical pairs. The decontamination methods investigated were thermal decontamination and air drying at room temperatures followed by detergent washing. Breakthrough time and steady-state permeation rate were determined by two different methods for new and decontaminated materials. The results showed that unless the contamination is limited to the outside surface of an elastomer (a material found in most barrier fabrics used in chemical protective clothing) or the chemical has a very large diffusion coefficient in the material, aeration and washing with detergent may not be an effective decontamination procedure for the type of solvent studied. On the other hand, thermal decontamination was shown to be effective in removing the contaminant from the matrix of the elastomers, and the decontaminated materials had permeation parameters similar to the new materials.     

Childhood cancer incidence rates and hazardous air pollutants in California: an exploratory analysis

Hazardous air pollutants (HAPs) are compounds shown to cause cancer or other adverse health effects. We analyzed population-based childhood cancer incidence rates in California (USA) from 1988 to 1994, by HAP exposure scores, for all California census tracts. For each census tract, we calculated exposure scores by combining cancer potency factors with outdoor HAP concentrations modeled by the U.S. Environmental Protection Agency. We evaluated the relationship between childhood cancer rates and exposure scores for 25 potentially carcinogenic HAPs emitted from mobile, area, and point sources and from all sources combined. Our study period saw 7,143 newly diagnosed cancer cases in California; of these, 6,989 (97.8%) could be assigned to census tracts and included in our analysis. Using Poisson regression, we estimated rate ratios (RRs) adjusted for age, race/ethnicity, and sex. We found little evidence for elevated cancer RRs for all sites or for gliomas among children living in high-ranking combined-source exposure areas. We found elevated RRs and a significant trend with increasing exposure level for childhood leukemia in tracts ranked highest for exposure to the combined group of 25 HAPs (RR = 1.21; 95% confidence interval, 1.03, 1.42) and in tracts ranked highest for point-source HAP exposure (RR = 1.32; 95% confidence interval, 1.11, 1.57). Our findings suggest an association between increased childhood leukemia rates and high HAP exposure, but studies involving more comprehensive exposure assessment and individual-level exposure data will be important for elucidating this relationship.