Web based listing of agents associated with new onset work-related asthma.

BACKGROUND: Work-related asthma is common and yet remains a challenge to diagnose. Access to a listing of agents associated with work-related asthma has been suggested as useful in assisting in the diagnosis. METHODS: The Association of Occupational and Environmental Clinics (AOEC) developed criteria that were used to review the peer-reviewed medical literature published in English. Based on this review, substances were designated either as a sensitizing agent or an irritant. The reviews were conducted by a board certified internist/pulmonologist/occupational medicine specialist from 2002 to 2007 and a board certified internist/occupational medicine physician from 2008- date. All reviews were then reviewed by the nine member AOEC board of directors. RESULTS: The original list of agents associated with new onset work-related asthma was derived from the tables of a text book on work-related asthma. After 13 years of review, there are 327 substances designated as asthma agents on the AOEC list; 173 (52.9%) coded as sensitizers, 35 (10.7%) as generally recognized as an asthma causing agent, four (1.2%) as irritants, two (0.6%) as both a sensitizer and an irritant and 113(34.6%) agents that still need to be reviewed. CONCLUSIONS: The AOEC has developed a readily available web based listing of agents associated with new onset work-related asthma in adults. The listing is based on peer-reviewed criteria. The listing is updated twice a year. Regular review of the peer-reviewed medical literature is conducted to determine whether new substances should be added to the list. Clinicians should find the list useful when considering the diagnosis of work-related asthma.

Lean mass predicts asthma better than fat mass among females.

The obesity phenotype associated with asthma is not known. Our objective was to define the relative contribution of various distributions of fat and lean mass to asthma prevalence. Data were obtained from 2,525 participants (including 1,422 females) who underwent dual-energy X-ray absorptiometry (DEXA) at the year 20 examination in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort. Total, truncal, arm and leg distributions of fat and lean mass were adjusted to the person's height. Self-reported asthma was the outcome. Asthma among females was associated with greater total fat mass, arm fat mass, total lean mass, truncal lean mass and arm lean mass. Among males, none of these mass measures were significantly associated with asthma. Among females, the association with asthma was stronger for total lean mass than for total fat mass. Further, among various regional distributions of lean and fat mass in females, truncal lean mass was the strongest predictor. Total lean mass is more strongly associated with asthma than total fat mass among females. These findings are contrary to the popular perception that excess physiological fat drives the obesity-asthma association. Rather, we hypothesise that ectopic fat within the "lean" tissues drives this association among females.

Association between asthma and serum adiponectin concentration in women.

BACKGROUND: The association of murine asthma with adiposity may be mediated by adiponectin, an anti-inflammatory adipokine with reduced serum concentrations in obese subjects. A study was undertaken to examine whether the serum adiponectin concentration is associated with human asthma and whether it explains the association between adiposity and asthma, particularly in women and in premenopausal women. METHODS: A cross-sectional analysis was performed of 2890 eligible subjects at year 15 of the Coronary Artery Risk Development in Young Adults (CARDIA) cohort and its YALTA ancillary study who had either current asthma or never asthma at that evaluation. Obesity was defined as body mass index (BMI) >or=30 kg/m(2). Multivariable logistic regression analysis was performed with current asthma status as the dependent variable. RESULTS: Women, but not men, with current asthma had a lower mean unadjusted serum adiponectin concentration than those with never asthma (p<0.001; p for sex interaction <0.001). Similarly, current asthma was related to obesity only in women (OR 3.31, 95% CI 2.00 to 5.46, p for sex interaction = 0.004); this association was little affected by adjusting for serum adiponectin. The prevalence of current asthma in premenopausal women was reduced in the highest compared with the lowest tertile of serum adiponectin concentration (OR 0.46, 95% CI 0.26 to 0.84, p = 0.03), after adjusting for BMI. However, the interaction between serum adiponectin concentration and BMI category on current asthma status was not significant in premenopausal women or women overall. CONCLUSIONS: A high serum adiponectin concentration may protect against current asthma in premenopausal women but does not explain the association between asthma and adiposity.

Asthma is associated with weight gain in females but not males, independent of physical activity.

We tested whether asthma diagnosis is associated with weight gain and physical activity in 4,547 18 to 30-yr-old African American and white men and women, followed prospectively for up to 10 yr. Baseline asthma was most frequent in African American men. Incident asthma was more frequent in women. Incident asthma was associated with highest and lowest baseline and change in body mass index (BMI), in a J-shaped curve, after adjustment for other factors. When stratified by sex, this association was seen only in females. Subjects on average decreased physical activity and gained weight over time, but there was no significant difference in asthma prevalence by physical activity at baseline or asthma incidence by change in physical activity. Cigarette smoking in females was significantly associated with asthma incidence, but serum cotinine level at baseline among nonsmokers (reflecting environmental tobacco smoke [ETS] exposure) was not significantly associated with asthma. We conclude that gain in BMI predisposes to new asthma diagnosis in female young adults, but decreased physical activity does not explain the association of weight gain with asthma.

Risk factors for asthma prevalence among urban and nonurban African American children.

Urban residence is a risk factor for asthma. We examined multiple risk factors simultaneously among African American children. We interviewed 2409 African American mothers of newborns who had at least 1 child at home under 18 years of age. Sixteen percent reported at least 1 child with physician-diagnosed asthma. Significantly associated with an asthmatic child were maternal asthma and allergies, maternal cigarette smoking, a humidifying device, and a gas range or oven in the home. Urban residence was related to asthma but became nonsignificant once other factors were controlled for. Asthma associated with urban residence may be explained by identifiable factors.

Hypersensitivity pneumonitis from ordinary residential exposures.

A previously healthy woman developed hypersensitivity pneumonitis of such severity that she required chronic systemic corticosteroid therapy for symptom control. Detailed investigation of her workplace and home environments revealed fungi in her typical suburban home, to which she had specific serum precipitating antibodies. Efforts to remove mold from the home were unsuccessful in relieving symptoms, and moving to another residence was the only intervention that allowed her to be withdrawn from corticosteroid therapy. Hypersensitivity pneumonitis is commonly associated with occupational or avocational exposures, such as moldy hay in farmers or bird antigen in bird breeders. We propose that hypersensitivity pneumonitis may occur in North America, as it does in Japan, from domestic exposures alone.

Association of reversible alopecia with occupational topical exposure to common borax-containing solutions.

Boron is widely used in industrial materials, most frequently as the salt borax. Systemic exposure (eg, ingestion) to boron in boric acid been associated with reversible toxic alopecia among other manifestations. There is scant clinical literature on alopecia caused by topical exposure to boron. We observed a series of 3 patients in 2 workplaces who suffered reversible alopecia from cutaneous boron exposure. The scalp alopecia was global in 1 patient and patchy in 2 patients. Alopecia was completely reversed by elimination or reduction of exposure to boron-containing materials in all 3 patients. We conclude that occupational topical exposure to boron in solutions may cause reversible alopecia.

Characterization of clinical tolerance to inhaled zinc oxide in naive subjects and sheet metal workers.

Clinical tolerance to the acute effects of zinc oxide inhalation develops in workers during periods of repeated exposure. The aims of this study were to determine whether clinical tolerance is accompanied by a reduction in the acute pulmonary inflammatory and cytokine responses to zinc oxide exposure and whether tolerance can be demonstrated in sheet metal workers who chronically inhale low levels of zinc oxide. Naive (never-exposed) subjects inhaled 5 mg/m3 zinc oxide on 1 or 3 days and underwent bronchoalveolar lavage 20 hours after the final exposure. Sheet metal workers inhaled zinc oxide on 1 day and control furnace gas on another day. Among naive subjects in whom tolerance was induced, bronchoalveolar lavage fluid percent neutrophils and interleukin-6 (IL-6) levels were significantly decreased compared with subjects who underwent only a single exposure. Sheet metal workers were much less symptomatic, but they still experienced a significant increase in plasma IL-6. The results indicate that clinical tolerance to zinc oxide is accompanied by reduced pulmonary inflammation and that chronically exposed sheet metal workers are not clinically affected by exposure to zinc oxide fume at the Occupational Safety and Health Administration Permissible Exposure Limit. The increase in IL-6 levels observed in the clinically responsive, and to a lesser extent, tolerant, states following zinc oxide inhalation is consistent with the dual role of IL-6 as a pyrogen and anti-inflammatory agent.

Hearing conservation for farmers: source apportionment of occupational and environmental factors contributing to hearing loss.

Those who work on farms continue to have a strikingly high prevalence of hearing loss, despite efforts to promote hearing conservation in agriculture. To develop improved hearing conservation programs, we performed a source apportionment analysis for hearing loss in a large, multiphasic health survey, the New York Farm Family Health and Hazard Survey. We used information from audiometric, otoscopic, and tympanometric examinations; detailed general health and farm exposure interviews; and a second interview that focused on additional potential determinants of hearing loss. Hearing loss on audiometry was significantly associated with increased age, male gender, education through high school or less, lifetime years of hunting with guns, lifetime years of use of a grain dryer, and a history of spraying crops during the previous year. Hearing conservation programs for farmers should thus be directed toward reduction in noise exposure, both from occupational and non-occupational sources. Additional study is needed to evaluate the association seen between crop spraying and hearing loss.

Clinical evaluation, management, and prevention of work-related asthma.

Work-related asthma (WRA) is asthma that is attributable to, or is made worse by, environmental exposures in the workplace. WRA has become the most prevalent occupational lung disease in developed countries, is more common than is generally recognized, and can be severe and disabling. Identification of workplace exposures causing and/or aggravating the asthma, and appropriate control or cessation of these exposures can often lead to reduction or even complete elimination of symptoms and disability. This depends on timely recognition and diagnosis of WRA. In this review, the diagnostic evaluation has been organized in a stepwise fashion to make it more practical for primary care physicians as well as physicians specializing in occupational diseases and asthma. WRA merits more widespread attention among clinicians, labor and management health and safety specialists, researchers, health care organizations, public health policy makers, industrial hygienists, and others interested in disease prevention.

Medical evaluation for respirator use.

The purpose of a respirator is to prevent the inhalation of harmful airborne substances or to provide a source of respirable air when breathing in oxygen-deficient atmospheres. For a physician to recommend the use of respirator, general background information on respiratory-protective devices is required. The first part of this clinical practice review describes the general aspects of industrial hygiene, respirators and a respirator-certification program. The second part addresses matters related to medical certification for respirator use. Medical certification for respirators is an important part of the activities of the occupational physician. To determine whether a worker is able to tolerate the added strain of a respiratory protective device is a complex process in which factors such as fitness for work, health of the individual, characteristics of the work itself, and the properties, type, and requirements of the respiratory protective device, have to be considered. Medical certification is of utmost importance for respirator use, and it should be viewed as an element in a comprehensive respiratory protection program. A comprehensive program is the key element in affording the workers' effective respiratory protection once the initial steps of the hierarchy of methods of hazard control have proved insufficient or infeasible. As a result, the need for the industrial hygiene/safety officer, the worker, the employer and the medical professional to work as a team is much more than in any other field of occupational medicine--a necessary requirement for making the right decision.

Healthy women's PEF variations with ambient summer concentrations of PM10, PM2.5, SO42-, H+, and O3.

The relationship between ambient air pollution and daily change in peak expiratory flow (PEF) was studied in a sample of 473 nonsmoking women (age 19 to 43 yr) in Virginia over summers 1995- 1996. Daily 24-h averages of particulate matter (PM2.5 and PM10), fine particulate sulfate (SO42-) and strong acid (H+), hourly ozone (O3), and select meteorologic variables (e.g., temperature) were collected at a regional outdoor monitoring site. Subjects took PEF measurements twice daily for a 2-wk period using a standard MiniWright peak flow meter. Concurrent measures for summer periods of 24-h PM2.5 (micrograms/m3) ranged from 3.5 to 59.7; H+ (nmol/m3) from 0 to 250; maximal daily 8-h average O3 (ppb) from 17.0 to 87.6. Morning PEF decrements were significantly associated with H+ and PM2. 5. An increase of 50 etamol/m3 of H+ and 10 micrograms/m3 of PM2.5 related to decreases of 0.89 (95% CI = 0.21 to 1.57) and 0.73 (95% CI = 0.07 to 1.38) L/min in morning PEF, respectively. Ozone was the only exposure related to evening PEF with 5-d cumulative lag exposure showing the greatest effect; 7.65 L/ min (95% CI = 2.25 to 13.0) decrease per 30 ppb O3 increase. Separate physiologic effects were observed for summer ambient concentrations of two different pollutants (PEF decrements related to PM2.5 in morning and O3 in evening) at concentrations below the new U.S. EPA 24-h ambient air quality standard for PM2.5 and 8-h standard for O3.

Association of ambient air quality with children's lung function in urban and rural Iran.

During the summer of 1994, a cross-sectional epidemiological study, in which the pulmonary function of children in Tehran was compared with pulmonary function in children in a rural town in Iran, was conducted. Four hundred children aged 5-11 y were studied. Daytime ambient nitrogen dioxide, sulfur dioxide, and particulate matter were measured with portable devices, which were placed in the children's neighborhoods on the days of study. Levels of these ambient substances were markedly higher in urban Tehran than in rural areas. Children's parents were questioned about home environmental exposures (including heating source and environmental tobacco smoke) and the children's respiratory symptoms. Pulmonary function was assessed, both by spirometry and peak expiratory flow meter. Forced expiratory volume in 1 s and forced vital capacity-as a percentage of predicted for age, sex and height-were significantly lower in urban children than in rural children. Both measurements evidenced significant reverse correlations with levels of sulfur dioxide, nitrogen dioxide, and particulate matter. Differences in spirometric lung function were not explained by nutritional status, as assessed by height and weight for age, or by home environmental exposures. Reported airway symptoms (i.e., cough, phlegm, and wheeze) were higher among rural children, whereas reported physician diagnosis of bronchitis and asthma were higher among urban children. The association between higher pollutant concentrations and reduced pulmonary function in this urban-rural comparison suggests that there is an effect of urban air pollution on short-term lung function and/or lung growth and development during the preadolescent years.

Persistent respiratory effects in survivors of the Bhopal disaster.

OBJECTIVE: To examine the role of exposure to the 1984 Bhopal gas leak in the development of persistent obstructive airways disease. DESIGN: Cross sectional survey. SETTING: Bhopal, India. SUBJECTS: Random sample of 454 adults stratified by distance of residence from the Union Carbide plant. MAIN OUTCOME MEASURES: Self reported respiratory symptoms; indices of lung function measured by simple spirometry and adjusted for age, sex, and height according to Indian derived regression equations. RESULTS: Respiratory symptoms were significantly more common and lung function (percentage predicted forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow between 25% and 75% of vital capacity (FEF25-75), and FEV1/FEV ratio) was reduced among those reporting exposure to the gas leak. The frequency of symptoms fell as exposure decreased (as estimated by distance lived from the plant), and lung function measurements displayed similar trends. These findings were not wholly accounted for by confounding by smoking or literacy, a measure of socioeconomic status. Lung function measurements were consistently lower in those reporting symptoms. CONCLUSION: Our results suggest that persistent small airways obstruction among survivors of the 1984 disaster may be attributed to gas exposure.

Determination of disability for patients with advanced lung disease.

To conclude, impairment ratings differ among various diseases and compensation programs. It therefore is important to note, at the outset, which compensation program the patient is eligible for because the requirements of the different programs may vary. The physician report must clearly state an opinion using terminology understandable to lay people. It should include the diagnosis, whether the condition is work-related or not, the evidence of impairment, and the severity of impairment. It should also state whether the resultant disability is temporary or permanent. In the case of work-related diseases, apportionment should be addressed. Finally, patients with advanced lung disease may be totally disabled from certain types of employment and yet may be eligible for vocational training. It is appropriate to describe the types of jobs and work the patient physically can and cannot do.

A new index of prognostic severity for chronic asthma.

OBJECTIVE: To develop a prognostic clinical index for adults with chronic stable asthma. DESIGN: Analysis of data from a 48-week randomized, crossover trial of regular vs as-needed inhaled beta-agonist therapy. PATIENTS: Eligible patients included 70 men and women between the ages of 15 and 64 years with asthma for > 1 year. OUTCOME MEASURE: Asthma deterioration within 20 weeks, defined as either a marked decline in FEV1 (> or = 1.0 L or > or = 30% from baseline) or initiation of systemic corticosteroid therapy for asthma exacerbation. RESULTS: Three baseline factors independently predicted asthma deterioration: frequent symptoms on waking in the 4 weeks before baseline, past hospitalization for asthma, and age 35 years or older. Based on cross-stratification and consolidation of these prognostic factors, an index was developed that stratified subjects into four risk groups with distinctive deterioration rates of 9%, 21%, 39%, and 67% (p<0.001). CONCLUSION: For adults with chronic stable asthma, three simple clinical factors can be combined to stratify effectively for risk of subsequent asthma deterioration.