CC16 polymorphisms in asthma, asthma subtypes, and asthma control in adults from the Agricultural Lung Health Study.

BACKGROUND: The club cell secretory protein (CC16) has anti-inflammatory and antioxidant effects and is a potential early biomarker of lung damage. The CC16 single nucleotide polymorphism (SNP) rs3741240 risk allele (A) has been inconsistently linked to asthma; other tagging SNPs in the gene have not been explored. The aim was to determine whether CC16 tagging polymorphisms are associated with adult asthma, asthma subtypes or asthma control in the Agricultural Lung Health Study (ALHS). METHODS: The ALHS is an asthma case-control study nested in the Agricultural Health Study cohort. Asthma cases were individuals with current doctor diagnosed asthma, likely undiagnosed asthma, or asthma-COPD overlap defined by questionnaire. We also examined asthma subtypes and asthma control. Five CC16 tagging SNPs were imputed to 1000 Genomes Integrated phase 1 reference panel. Logistic regression was used to estimate associations between CC16 SNPs and asthma outcomes adjusted for covariates. RESULTS: The sample included 1120 asthma cases and 1926 controls of European ancestry, with a mean age of 63 years. The frequency of the risk genotype (AA) for rs3741240 was 12.5% (n = 382). CC16 rs3741240 was not associated with adult asthma outcomes. A tagging SNP in the CC16 gene, rs12270961 was associated with uncontrolled asthma (n = 208, ORadj= 1.4, 95% CI 1.0, 1.9; p = 0.03). CONCLUSION: This study, the largest study to investigate associations between CC16 tagging SNPs and asthma phenotypes in adults, did not confirm an association of rs3741240 with adult asthma. A tagging SNP in CC16 suggests a potential relationship with asthma control.

The Association of Airflow Obstruction with Occupational Exposures in a Sample of Rural Adults in Iowa.

A recent article reported that occupational exposure to vapor-gas, dust, and fumes (VGDF) was more common in a sample of rural adults than in a sample of adults in urban settings. In another study of the same urban adults, airflow obstruction (AO) was associated with occupational VGDF and the combination of smoking and occupational exposure. The goal of the current study was to determine if similar associations were evident in the sample of rural adults. We analyzed enrollment data from the Keokuk County Rural Health Study (KCRHS), which investigated the health of rural residents in Iowa. We used the same methods as the study of urban adults. A job-exposure matrix (JEM) assigned an occupational VGDF exposure level based on each participants' last reported job. The health outcome was AO, defined as both the forced expiratory volume in one second (FEV1) and the FEV1/forced vital capacity (FVC) ratio < lower limit of normal. Of the 1699 KCRHS participants, 436 (25.7%) had high total VGDF occupational exposure, 661 (38.9%) had ever smoked cigarettes, and 110 (6.5%) had AO. The crude frequency of AO increased across the joint categories of smoking (never, ever) and high exposure (no, yes) (p < 0.05 for linear trend). After adjusting for potential confounders, AO was associated with high total occupational VGDF exposure only among smokers (OR = 1.81, 95% CI 1.002 to 3.26). In conclusion, the association of AO with occupational exposure in the current study of rural adults was similar to what was previously observed among urban adults.

Exposure to second-hand tobacco smoke and respiratory symptoms in non-smoking adults: cross-sectional data from the general population of Telemark, Norway.

BACKGROUND: In Norway, data on the association between second-hand tobacco smoke (SHS) exposure at home and respiratory symptoms in adults are limited. METHODS: We assessed the association between self-reported exposure to SHS and the prevalence of respiratory symptoms among never-smokers aged 16 to 50 years from the general population who were included in a cross-sectional population-based study in Telemark County, Norway. Logistic regression analysis was used to estimate the odds ratios of symptoms among 8850 never-smokers who provided an affirmative response to questions regarding SHS; 504 (5.7%) of these reported that they lived in a home with daily or occasional indoor smoking. RESULTS: Productive cough and nocturnal dyspnoea were statistically associated with daily SHS exposure (ORs 1.5 [95% CI 1.04-2.0] and 1.8 [1.2-2.7], respectively). In analyses stratified by gender, nocturnal dyspnoea was associated with SHS among women (OR 1.8 [1.1-3.1]), but not among men (OR 0.93 [0.49-1.8]). Symptoms were not associated with occasional SHS exposure in the entire group, but infrequent exposure among men only was associated with increased prevalence of chronic cough; (OR 1.6; [1.04-2.6]) and was negatively associated with wheeze; (OR 0.44 [0.21-0.92)]. CONCLUSIONS: Daily SHS exposure in private homes was associated with productive cough and nocturnal dyspnoea. Our results suggest that preventive measures may be needed to reduce the respiratory effects of SHS at home. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02073708 Registered February 27. 2014.

Development of a job-task-exposure matrix to assess occupational exposure to disinfectants among US nurses.

OBJECTIVES: Occupational exposure to disinfectants is associated with work-related asthma, especially in healthcare workers. However, little is known about the specific products involved. To evaluate disinfectant exposures, we designed job-exposure (JEM) and job-task-exposure (JTEM) matrices, which are thought to be less prone to differential misclassification bias than self-reported exposure. We then compared the three assessment methods: self-reported exposure, JEM and JTEM. METHODS: Disinfectant use was assessed by an occupational questionnaire in 9073 US female registered nurses without asthma, aged 49-68 years, drawn from the Nurses' Health Study II. A JEM was created based on self-reported frequency of use (1-3, 4-7 days/week) of 7 disinfectants and sprays in 8 nursing jobs. We then created a JTEM combining jobs and disinfection tasks to further reduce misclassification. Exposure was evaluated in 3 classes (low, medium, high) using product-specific cut-offs (eg, <30%, 30-49.9%, ≥50%, respectively, for alcohol); the cut-offs were defined from the distribution of self-reported exposure per job/task. RESULTS: The most frequently reported disinfectants were alcohol (weekly use: 39%), bleach (22%) and sprays (20%). More nurses were classified as highly exposed by JTEM (alcohol 41%, sprays 41%, bleach 34%) than by JEM (21%, 30%, 26%, respectively). Agreement between JEM and JTEM was fair-to-moderate (κ 0.3-0.5) for most disinfectants. JEM and JTEM exposure estimates were heterogeneous in most nursing jobs, except in emergency room and education/administration. CONCLUSIONS: The JTEM may provide more accurate estimates than the JEM, especially for nursing jobs with heterogeneous tasks. Use of the JTEM is likely to reduce exposure misclassification.

Breath-taking jobs: a case-control study of respiratory work disability by occupation in Norway.

BACKGROUND: The current knowledge on respiratory work disability is based on studies that used crude categories of exposure. This may lead to a loss of power, and does not provide sufficient information to allow targeted workplace interventions and follow-up of patients with respiratory symptoms. OBJECTIVES: The aim of this study was to identify occupations and specific exposures associated with respiratory work disability. METHODS: In 2013, a self-administered questionnaire was mailed to a random sample of the general population, aged 16-50, in Telemark County, Norway. We defined respiratory work disability as a positive response to the survey question: 'Have you ever had to change or leave your job because it affected your breathing?' Occupational exposures were assessed using an asthma-specific job-exposure matrix, and comparison of risks was made for cases and a median of 50 controls per case. RESULTS: 247 workers had changed their work because of respiratory symptoms, accounting for 1.7% of the respondents ever employed. The 'breath-taking jobs' were cooks/chefs: adjusted OR 3.6 (95% CI 1.6 to 8.0); welders: 5.2 (2.0 to 14); gardeners: 4.5 (1.3 to 15); sheet metal workers: 5.4 (2.0 to 14); cleaners: 5.0 (2.2 to 11); hairdressers: 6.4 (2.5 to 17); and agricultural labourers: 7.4 (2.5 to 22). Job changes were also associated with a variety of occupational exposures, with some differences between men and women. CONCLUSIONS: Self-report and job-exposure matrix data showed similar findings. For the occupations and exposures associated with job change, preventive measures should be implemented.

Agents and trends in health care workers' occupational asthma.

BACKGROUND: There is a disproportionately high number of cases of work-related asthma occurring in health care occupations due to agents such as glutaraldehyde, latex and cleaning products. AIMS: To understand the causes and measure trends over time of occupational asthma (OA) in health care workers (HCWs). METHODS: We reviewed OA notifications from the Midland Thoracic Society's Surveillance Scheme of Occupational Asthma (SHIELD) database in the West Midlands, UK, from 1991 to 2011 and gathered data on occupation, causative agent and annual number of notifications. RESULTS: There were 182 cases of OA in HCWs (median annual notifications = 7; interquartile range [IQR] = 5-11), representing 5-19% of annual SHIELD notifications. The modal annual notification was 20 (in 1996); notifications have declined since then, in line with total SHIELD notifications. The majority of cases (136; 75%) occurred in nursing, operating theatre, endoscopy and radiology staff. The most frequently implicated agents were glutaraldehyde (n = 69), latex (n = 47) and cleaning products (n = 27), accounting for 79% of the 182 cases. Cleaning product-related OA was an emerging cause with 22 cases after 2001 and only 5 cases between 1991 and 2000. CONCLUSIONS: Control measures within the UK National Health Service have seen a decline in OA in HCWs due to latex and glutaraldehyde, though OA remains a problem amongst HCWs exposed to cleaning products. Continuing efforts are required to limit the number of cases in this employment sector.

The occupational contribution to severe exacerbation of asthma.

The goal of this study was to identify occupational risk factors for severe exacerbation of asthma and estimate the extent to which occupation contributes to these events. The 966 participants were working adults with current asthma who participated in the follow-up phase of the European Community Respiratory Health Survey. Severe exacerbation of asthma was defined as self-reported unplanned care for asthma in the past 12 months. Occupations held in the same period were combined with a general population job-exposure matrix to assess occupational exposures. 74 participants reported having had at least one severe exacerbation event, for a 1-yr cumulative incidence of 7.7%. From regression models that controlled for confounders, the relative risk (RR) was statistically significant for low (RR 1.7, 95% CI 1.1-2.6) and high (RR 3.6, 95% CI 2.2-5.8) biological dust exposure, high mineral dust exposure (RR 1.8, 95% CI 1.02-3.2), and high gas and fumes exposure (RR 2.5, 95% CI 1.2-5.5). The summary category of high dust, gas, or fumes exposure had RR 3.1 (95% CI 1.9-5.1). Based on this RR, the population attributable risk was 14.7% among workers with current asthma. These results suggest occupation contributes to approximately one in seven cases of severe exacerbation of asthma in a working population, and various agents play a role.

Pesticide use and adult-onset asthma among male farmers in the Agricultural Health Study.

Although specific pesticides have been associated with wheeze in farmers, little is known about pesticides and asthma. Data from 19,704 male farmers in the Agricultural Health Study were used to evaluate lifetime use of 48 pesticides and prevalent adult-onset asthma, defined as doctor-diagnosed asthma after the age of 20 yrs. Asthma cases were categorised as allergic (n = 127) and nonallergic (n = 314) based on their history of eczema or hay fever. Polytomous logistic regression, controlling for age, state, smoking and body mass, was used to assess pesticide associations. High pesticide exposure events were associated with a doubling of both allergic and nonallergic asthma. For ever-use, 12 individual pesticides were associated with allergic asthma and four with nonallergic asthma. For allergic asthma, coumaphos (OR 2.34; 95% CI 1.49-3.70), heptachlor (OR 2.01; 95% CI 1.30-3.11), parathion (OR 2.05; 95% CI 1.21-3.46), 80/20 mix (carbon tetrachloride/carbon disulfide) (OR 2.15; 95% CI 1.23-3.76) and ethylene dibromide (OR 2.07; 95% CI 1.02-4.20) all showed ORs of >2.0 and significant exposure-response trends. For nonallergic asthma, DDT (dichlorodiphenyltrichloroethane) showed the strongest association (OR 1.41; 95% CI 1.09-1.84), but with little evidence of increasing asthma with increasing use. Current animal handling and farm activities did not confound these results. There was little evidence that allergy alone was driving these associations. In conclusion, pesticides may be an overlooked contributor to asthma risk among farmers.

Association of respiratory symptoms and asthma with occupational exposures: findings from a population-based cross-sectional survey in Telemark, Norway.

OBJECTIVES: The aim of this study was to estimate the prevalence of respiratory symptoms and physician-diagnosed asthma and assess the impact of current occupational exposure. DESIGN: Cross-sectional analyses of the prevalence of self-reported respiratory health and association with current occupational exposure in a random sample of the general population in Telemark County, Norway. SETTINGS: In 2013, a self-administered questionnaire was mailed to a random sample of the general population, aged 16-50, in Telemark, Norway. The overall response rate was 33%, comprising 16 099 responders. OUTCOME MEASURES: The prevalence for respiratory symptoms and asthma, and OR of respiratory symptoms and asthma for occupational groups and exposures were calculated. Occupational exposures were assessed using self-reported exposure and an asthma-specific job-exposure matrix (JEM). RESULTS: The prevalence of physician-diagnosed asthma was 11.5%. For the occupational groups, the category with agriculture/fishery workers and craft/related trade workers was associated with wheezing and asthma attack in the past 12 months, showing OR 1.3 (1.1 to 1.6) and 1.9 (1.2 to 2.8), respectively. The group including technicians and associated professionals was also associated with wheezing OR 1.2 (1.0 to 1.3) and asthma attack OR 1.4 (1.1 to 1.9). The JEM data show that exposure to flour was associated with wheezing OR 3.2 (1.4 to 7.3) and woken with dyspnoea OR 3.5 (1.3 to 9.5), whereas exposures to diisocyanates, welding/soldering fumes and exposure to vehicle/motor exhaust were associated with dyspnoea OR 2.9 (1.5 to 5.7), 3.2 (1.6 to 6.4) and 1.4 (1.0 to 1.8), respectively. CONCLUSIONS: The observed prevalence of physician-diagnosed asthma was 11.5%. The 'manual' occupations were associated with respiratory symptoms. Occupational exposure to flour, diisocyanates, welding/soldering fumes and vehicle/motor exhaust was associated with respiratory symptoms in the past 12 months and use of asthma medication. However, prospective data are needed to confirm the observed associations.

The frequency of workplace exacerbation among health maintenance organisation members with asthma.

OBJECTIVES: Workplace conditions can potentially contribute to the worsening of asthma, yet it is unclear what percentage of adults with asthma experience workplace exacerbation of symptoms. The objective of this investigation was to determine the prevalence of workplace exacerbation of asthma (WEA). METHODS: Adults with asthma aged 18-44 were enrolled into the baseline survey of a longitudinal study. Members of a health maintenance organisation were considered candidates for participation if they fulfilled membership, diagnostic, and treatment criteria based on automated review of electronic billing, claims, and pharmacy records. Diagnosis and treatment were confirmed by manual review of medical records. A telephone questionnaire was administered. A work related symptom score was assigned to each participant based on responses to questions about work related asthma symptoms, medication use, and symptom triggers. Blinded to participants' answers to these questions, two researchers independently reviewed the self-reported work histories and assigned exposure ratings. A final exposure score was then calculated. Participants with sufficient evidence for work related symptoms and exposure were classified as having WEA. RESULTS: Of the 598 participants with complete data, 557 (93%) were working, and 136 (23%) fulfilled the criteria for WEA. Those with WEA were more likely to be male and to report that they had been bothered by asthma symptoms during the past seven days. CONCLUSIONS: Workplace exacerbation of asthma was common in this study population, occurring in over a fifth of these adults with asthma. Physicians should consider that work can contribute to the exacerbation of symptoms when treating adults with asthma.

Occupational exposures associated with severe exacerbation of asthma.

BACKGROUND: The exacerbation of asthma by workplace conditions is common, but little is known about which agents pose a risk. OBJECTIVE: We used data from an existing survey of adults with asthma to identify occupational exposures associated with severe exacerbation of asthma. DESIGN: Questionnaires were completed by 557 working adults with asthma. Severe exacerbation of asthma in the past 12 months was defined as asthma-related hospitalization, or reports of both unplanned asthma care and treatment with a short course of oral corticosteroids. Occupational exposures for the same time period were assessed using an asthma-specific job exposure matrix. We modeled severe exacerbation to yield prevalence ratios (PRs) for exposures while controlling for potential confounders. RESULTS: A total of 164 participants (29%) were positive for severe exacerbation, and 227 (40.8%) were assessed as being exposed to asthma agents at work. Elevated PRs were observed for several specific agents, notably the irritant subcategories of environmental tobacco smoke (PR 1.84, 95%CI 1.34-2.51) among all participants, inorganic dusts (PR 2.53, 95%CI 1.37-4.67) among men, and the low molecular weight subcategory of other highly reactive agents (PR 1.97, 95%CI 1.08-3.60) among women. CONCLUSION: Among working adults with asthma, severe exacerbation was associated with several occupational agents.

The use of portable peak flowmeters in the surveillance of occupational asthma.

The purpose of this study was to identify the strengths and limitations of using portable peak flowmeters to document suspected cases of occupational asthma that were reported to a statewide surveillance project. The New Jersey Department of Health conducts surveillance for occupational asthma as part of the federally sponsored Sentinel Event Notification System for Occupational Risks (SENSOR). Between May 1988 and January 1990, 70 cases were reported voluntarily by physicians. Subjects who were still employed in suspected work sites were requested to test themselves for at least 15 days, using portable peak flowmeters to generate serial measurements of their peak expiratory flow rate (PEFR). For each of the 14 subjects who were successfully tested, the PEFR data provided valuable information about their asthma-work association. However, a large number of subjects whose cases were reported (56) either could not be tested or were not successfully tested. The proportion of subjects completing the test would probably improve if it were conducted when their conditions were first diagnosed. Accordingly, the collection of serial peak flow measurements to document occupational asthma would best be initiated by the treating physician when the patient first sought care, rather than waiting until after the case was reported to the state health department.

A descriptive study of work aggravated asthma.

BACKGROUND AND AIMS: Work related asthma (WRA) is one of the most frequently reported occupational lung diseases in a number of industrialised countries. A better understanding of work aggravated asthma (WAA), as well as work related new onset asthma (NOA), is needed to aid in prevention efforts. METHODS: WAA and NOA in the United States were compared using cases reported to the National Institute for Occupational Safety and Health (NIOSH) from four state Sentinel Event Notification Systems for Occupational Risks (SENSOR) surveillance programmes for 1993-95. RESULTS: A total of 210 WAA cases and 891 NOA cases were reported. WAA cases reported mineral and inorganic dusts as the most common exposure agent, as opposed to NOA cases, in which diisocyanates were reported most frequently. A similar percentage of WAA and NOA cases still experienced breathing problems at the time of the interview or had visited a hospital or emergency room for work related breathing problems. NOA cases were twice as likely to have applied for workers' compensation compared with WAA cases. However, among those who had applied for worker compensation, approximately three-fourths of both WAA and NOA cases had received awards. The services and manufacturing industrial categories together accounted for the majority of both WAA (62%) and NOA (75%) cases. The risk of WAA, measured by average annual rate, was clearly the highest in the public administration (14.2 cases/10(5)) industrial category, while the risk of NOA was increased in both the manufacturing (3.2 cases/10(5)) and public administration (2.9 cases/10(5)) categories. CONCLUSIONS: WAA cases reported many of the same adverse consequences as NOA cases. Certain industries were identified as potential targets for prevention efforts based on either the number of cases or the risk of WAA and NOA.

Lung cancer mortality in a cohort of older pulp and paper workers.

The occurrence of deaths due to lung cancer was studied among 883 white male workers from a pulp and paper company in northern New Hampshire. All subjects had participated in a longitudinal study of respiratory morbidity, and data from interviews were used to construct lifetime cigarette smoking and occupational histories. Most of the subjects had entered follow-up in the 1960s and, at that time, their mean age was 51 years and they had worked for the pulp and paper company a mean of 25 years. By the end of follow-up in 1992, the 512 deceased subjects included 35 whose underlying cause of death had been lung cancer. With an internal comparison using the Cox proportional-hazards model, the hazard ratio for sulfite pulp mill work was 2.5 (95% CI 1.3-4.9), while controlling for the effects of age, cigarette smoking, and work in other parts of the pulping operation. In addition, the hazard ratio for the combination of >35 pack-years of smoking and >10 years sulfite mill work was greater than the product of the hazard ratios for each factor alone. While these findings are consistent with past asbestos exposure in the sulfite pulp mill environment, the absence of mesothelioma cases is inconsistent with this type of exposure.

An evaluation of the incidence of work-related asthma in the United States.

The objective of the study was to estimate the incidences of physician-diagnosed cases of work-related asthma (WRA) in Michigan and the entire United States. The statewide surveillance system for WRA in Michigan receives reports primarily from three sources: physicians, hospital discharge data, and worker's compensation claims. Knowledge of the overlap in reports from these sources was used in conjunction with capture-recapture methods to estimate the total number of diagnosed cases of WRA, and incidence rates were calculated using the estimated number of civilian employees in Michigan as the population at risk. For the entire United States, the product of a national incidence rate for asthma among adults and estimates of the proportion that is work-related was used. A total of 933 cases of WRA were reported to the Michigan surveillance program during 1988-1995, of which 904 were reported by at least one of the three main sources and equaled an average incidence of 27 cases/10(6)/year. This estimate was less than the range of estimates 58 to 204 cases/10(6)/year in Michigan arrived at using the capture-recapture methods. The national estimates of WRA ranged from 63 to 441 cases/10(6)/year. The authors' indirect estimates are closer to estimates from Canada, Sweden, and Finland than most existing direct estimates in the United States, but probably still underestimates the magnitude of WRA incidence because of the limitations of physician recognition of the work-relatedness of asthma among adults.

Young adults' knowledge, attitudes, and behavior about abortions in young women.

OBJECTIVE: To document opinions and decision-making strategies of young adults regarding abortions for young women. METHODS: Eighty-nine male and 215 female college students completed a questionnaire on abortion during routine visits to their university health center. RESULTS: Among the salient findings, most respondents took a pro-abortion stance for girls under 18 in cases of rape (92% of students), incest (90%), or danger to the girl's health (90%). A much lower priority was given for abortion in cases of fetal abnormalities (55% of students), economic hardship (51%), or for girls who were married (55%). Abortion was considered acceptable regardless of circumstances by 46% of students and never a good idea by 18%. The outcome of unplanned pregnancies for minors should be decided by the girl (90% of students), partner (55%), parents (29%), and state or federal law (8%). Abortions for minors should require parental notification (45%) or consent (33%). Although only one student felt illegal abortions were safe, 19% would seek this kind of abortion and 4% of females would try to cause their own miscarriage if abortions were outlawed in the United States. CONCLUSIONS: The vast majority of young adults believed that girls under 18 should retain the right to decide the outcome of their pregnancy and should not be subjected to governmental restrictions. The highest priority for abortion was given to girls who had been victimized or whose health was at risk. Although nearly all respondents are aware of the hazards of criminal abortions, many would resort to such unsafe practices if legal alternatives were no longer available.

Talking to teens about family problems. An opportunity for prevention.

Most pediatricians do not screen for family problems as part of routine adolescent health care. This study documents fears, worries, and concerns about family issues expressed by 147 teenagers on a confidential questionnaire during consecutive initial visits to an adolescent medicine clinic in a university hospital setting. Among the salient findings, 44% had thought about running away from home, 42% reported having been subjected to some form of abuse, and 33% had felt like hurting themselves or someone else. Twenty-eight percent reported conflict in their home, 27% were having problems with their family, and 20% were concerned about their parent's relationship. In addition, 27% worried about the physical or mental health of family members and 22% believed that a family member had a problem with alcohol or other drugs. Twelve percent did not have a confidant with whom to discuss their innermost concerns. The data demonstrate a high frequency of stressful and anxiety-provoking family situations as reported by adolescents on a confidential questionnaire. Pediatricians who wish to provide comprehensive services to their young adult patients must be prepared to discuss such issues on a routine basis.

Anticipatory guidance for the adolescent. Parents' concerns.

Parents' opinions regarding anticipatory guidance for adolescents have not been adequately investigated. In this study, 932 parents of adolescents completed a computerized questionnaire listing 30 common psychosocial-medical concerns of adolescence. Respondents were asked how important it is for private pediatricians to discuss these topics with their teenagers during regular checkups. Ten items were rated important by > or = 90% of parents, 22 items by > or = 80%, and 29 items by > or = 66%. Heeding parents' expectations and concerns, pediatricians should incorporate discussions of psychosocial-medical issues as a meaningful component of routine adolescent health care.

Patients with multiple chemical sensitivities in an occupational health clinic: presentation and follow-up.

Thirty-five people with work-related Multiple Chemical Sensitivities were studied to learn about the onset and progression of illness. The subjects were selected from patients at an occupational health clinic. Individuals were identified as subjects if they fulfilled a seven-point case definition for Multiple Chemical Sensitivities and if onset of symptoms was related to workplace exposures. Three occupational exposures to solvents, poor indoor-air quality, and remodeling were associated with onset of Multiple Chemical Sensitivities in 63% of the subjects. Symptoms indicative of a nervous-system disorder topped the list of the most frequently reported symptoms. Commonalities in exposures and symptoms suggest that Multiple Chemical Sensitivities represents a distinct diagnostic category. Even with an incomplete understanding of etiology, it may be possible to limit the onset of work-related Multiple Chemical Sensitivities.