Asthma, chronic bronchitis, and exposure to irritant agents in occupational domestic cleaning: a nested case-control study

Occupational asthma: new deleterious agents at the workplace

This article summarizes the main new categories of occupational agents responsible for causing occupational asthma, with and without a latency period reported in the last 10 years. It also reports examples of occupational agents for which the fabrication processing or use have influenced the outcome of occupational asthma.

Heart rate variability in association with frequent use of household sprays and scented products in SAPALDIA

BACKGROUND

Household cleaning products are associated with adverse respiratory health outcomes, but the cardiovascular health effects are largely unknown.

OBJECTIVE

We determined if long-term use of household sprays and scented products at home was associated with reduced heart rate variability (HRV), a marker of autonomic cardiac dysfunction.

METHODS

We recorded 24-hr electrocardiograms in a cross-sectional survey of 581 Swiss adults, ≥ 50 years of age, who answered a detailed questionnaire regarding their use of household cleaning products in their homes. The adjusted average percent changes in standard deviation of all normal-to-normal intervals in 24 hr (24-hr SDNN) and total power (TP) were estimated in multiple linear regression in association with frequency [< 1, 1-3, or 4-7 days/week, unexposed (reference)] of using cleaning sprays, air freshening sprays, and scented products.

RESULTS

Decreases in 24-hr SDNN and TP were observed with frequent use of all product types, but the strongest reductions were associated with air freshening sprays. Compared with unexposed participants, we found that using air freshening sprays 4-7 days/week was associated with 11% [95% confidence interval (CI): -20%, -2%] and 29% (95% CI: -46%, -8%) decreases in 24-hr SDNN and TP, respectively. Inverse associations of 24-SDNN and TP with increased use of cleaning sprays, air freshening sprays, and scented products were observed mainly in participants with obstructive lung disease (p < 0.05 for interactions).

CONCLUSIONS

In predominantly older adult women, long-term frequent use of household spray and scented products was associated with reduced HRV, which suggests an increased risk of cardiovascular health hazards. People with preexisting pulmonary conditions may be more susceptible.

Occupation and the prevalence of respiratory health symptoms and conditions: the Atherosclerosis Risk in Communities Study

OBJECTIVES

To examine associations between occupation and respiratory health in a large, population-based cohort of adults in the United States.

METHODS

Data from 15,273 participants, aged 45 to 64 years, in the Atherosclerosis Risk in Communities study were used to examine associations of current or most recent job held with the prevalence of self-reported chronic cough, chronic bronchitis, wheezing, asthma, and measures of lung function collected by spirometry.

RESULTS

Eleven percent of participants reported wheezing and 9% were classified as having airway obstruction. Compared with individuals in managerial and administrative jobs, increased prevalences of respiratory outcomes were observed among participants in selected occupations, including construction and extractive trades (wheezing, prevalence ratio = 1.92, 95% confidence interval = 1.35, 2.73; airway obstruction, prevalence ratio = 1.31, 95% confidence interval = 1.05, 1.65).

CONCLUSIONS

Specific occupations are associated with adverse respiratory health.

Transient receptor potential genes, smoking, occupational exposures and cough in adults

Background

Transient receptor potential (TRP) vanilloid and ankyrin cation channels are activated by various noxious chemicals and may play an important role in the pathogenesis of cough. The aim was to study the influence of single nucleotide polymorphisms (SNPs) in TRP genes and irritant exposures on cough.

Methods

Nocturnal, usual, and chronic cough, smoking, and job history were obtained by questionnaire in 844 asthmatic and 2046 non-asthmatic adults from the Epidemiological study on the Genetics and Environment of Asthma (EGEA) and the European Community Respiratory Health Survey (ECRHS). Occupational exposures to vapors, gases, dusts, and/or fumes were assessed by a job-exposure matrix. Fifty-eight tagging SNPs in TRPV1, TRPV4, and TRPA1 were tested under an additive model.

Results

Statistically significant associations of 6 TRPV1 SNPs with cough symptoms were found in non-asthmatics after correction for multiple comparisons. Results were consistent across the eight countries examined. Haplotype-based association analysis confirmed the single SNP analyses for nocturnal cough (7-SNP haplotype: p-global = 4.8 × 10^-6) and usual cough (9-SNP haplotype: p-global = 4.5 × 10^-6). Cough symptoms were associated with exposure to irritants such as cigarette smoke and occupational exposures (p < 0.05). Four polymorphisms in TRPV1 further increased the risk of cough symptoms from irritant exposures in asthmatics and non-asthmatics (interaction p < 0.05).

Conclusions

TRPV1 SNPs were associated with cough among subjects without asthma from two independent studies in eight European countries. TRPV1 SNPs may enhance susceptibility to cough in current smokers and in subjects with a history of workplace exposures.

Irritant-induced airway disorders

Thousands of persons experience accidental high-level irritant exposures each year but most recover and few die. Irritants function differently than allergens because their actions proceed nonspecifically and by nonimmunologic mechanisms. For some individuals, the consequence of a single massive exposure to an irritant, gas, vapor or fume is persistent airway hyperresponsiveness and the clinical picture of asthma, referred to as reactive airways dysfunction syndrome (RADS). Repeated irritant exposures may lead to chronic cough and continual airway hyperresponsiveness. Cases of asthma attributed to repeated irritant-exposures may be the result of genetic and/or host factors.

Effect of exposure to detergents and other chemicals on biomarkers of pulmonary response in exhaled breath from hospital cleaners: a pilot study

PURPOSE

The main aim of the study was to provide evidence whether professional cleaning was associated with biomarkers of lung damage in non-invasively collected biological fluids (exhaled air and exhaled breath condensate--EBC).

MATERIALS AND METHODS

This cross-sectional study involved 40 cleaners regularly exposed to cleaning detergents and 40 controls. The subjects completed a standard questionnaire from European Community Respiratory Health Survey (ECRHS II) and underwent a spirometry. Fractional exhaled nitric oxide (F(E)NO) was measured online, and pH, ammonium (NH(4) (+)), H(2)O(2) and 4-hydroxynonenal (4-HNE) were assayed in EBC.

RESULTS

Among the cleaners, the frequency of asthma and rhinitis was, respectively, 2.5 and 20%. The most frequently reported symptoms were sneezing (27.5%), nasal and/or pharyngeal pruritus (25%), ocular pruritus (22.5%) and cough (22.5%). There were no significant differences in comparison with the control group. Median F(E)NO levels were higher in African than in Caucasian cleaners (21.5 [16.5-30.0] ppb and 18.0 [13.5-20.5] ppb; p < 0.05). H(2)O(2)-EBC (0.26 [0.09-0.53] μM vs. 0.07 [0.04-0.15] μM; p < 0.01), NH(4) (+)-EBC (857 [493-1,305] μM vs. 541 [306-907] μM; p < 0.01) and pH-EBC (8.17 [8.09-8.24] vs. 8.06 [7.81-8.10]; p < 0.01) were higher in the cleaners than in the controls. Finally, the cleaners showed significant correlations between pH-EBC and NH(4) (+)-EBC (r = 0.33, p < 0.05) and a weak correlation between 4-HNE-EBC and H(2)O(2)-EBC (r = 0.37, p < 0.05).

CONCLUSION

The promising role of EBC analysis in biomonitoring of exposed workers was confirmed. It was also possible to identify the potential biomarkers of exposure to alkaline products (increased ammonium-EBC and pH-EBC levels) and potential biomarkers of oxidative stress (increased H(2)O(2)-EBC levels correlated with 4-HNE-EBC levels) in workers with no signs of airway diseases.

Non-sensitising air pollution at workplaces and adult-onset asthma in the beginning of this millennium

PURPOSE

This case-control study was undertaken to elucidate the controversy concerning whether low-level, long-term exposure to non-sensitising air pollution at workplaces may cause asthma.

METHODS

A case-control study of 192 adult-onset asthma cases aged 20-65 years and 323 controls was conducted in the southeast of Sweden. Cases were identified from computerised registers from the region, diagnosed 2000-2004 and diagnoses were confirmed via medical files. Referents were randomised from the population register of the region. Exposure was monitored by a 16-page questionnaire. Special attention was devoted to identifying and in the final analyses excluding subjects exposed to sensitising agents.

RESULTS

Three years or more of occupational exposure to air pollution from dust, smoke, fumes or vapours before the year of diagnosis by analyses adjusting for age yielded an increased risk for asthma (OR = 2.3, 95% CI 1.2-4.2) in men, while in women, no risk was seen. In a multiple logistic regression analysis in men without allergy in childhood, a significant risk was seen (OR = 2.8, 95% CI 1.07-7.4), when subjects exposed to identified allergens were excluded. In women, no excess risk was observed from occupational air pollution.

CONCLUSION

The results of this study support an association between occupational exposure to low level non-sensitising air pollution and adult-onset asthma in men.

Occupational asthma: etiologies and risk factors

The purpose of this article is to critically review the available evidence pertaining to occupational, environmental, and individual factors that can affect the development of occupational asthma (OA). Increasing evidence suggests that exploration of the intrinsic characteristics of OA-causing agents and associated structure-activity relationships offers promising avenues for quantifying the sensitizing potential of agents that are introduced in the workplace. The intensity of exposure to sensitizing agents has been identified as the most important environmental risk factor for OA and should remain the cornerstone for primary prevention strategies. The role of other environmental co-factors (e.g., non-respiratory routes of exposure and concomitant exposure to cigarette smoke and other pollutants) remains to be further delineated. There is convincing evidence that atopy is an important individual risk factor for OA induced by high-molecular-weight agents. There is some evidence that genetic factors, such as leukocyte antigen class II alleles, are associated with an increased risk of OA; however, the role of genetic susceptibility factors is likely to be obscured by complex gene-environment interactions. OA, as well as asthma in general, is a complex disease that results from multiple interactions between environmental factors and host susceptibilities. Determining these interactions is a crucial step towards implementing optimal prevention policies.

Airway response to chlorine inhalation (bleach) among cleaning workers with and without bronchial hyperresponsiveness

BACKGROUND

Symptoms of obstructive lung disease in domestic cleaning staff have been related to the use of bleach and other irritant cleaning products.

MATERIAL AND METHODS

Included in the study were thirteen cleaning employees with work-related asthma-like symptoms, three asthmatic controls and three atopic subjects without bronchial hyperresponsiveness (BHR) who had no exposure to cleaning products. The study protocol consisted of a methacholine test, sputum induction and fraction of exhaled nitric oxide measurement (FENO) both at baseline and 24 hr after a 1-hr inhalation challenge with either placebo or bleach at a concentration of 0.4 ppm of chlorine.

RESULTS

The inhalation of the placebo caused no bronchial reactions. Mean maximum fall in FEV(1) during challenge testing with bleach was significantly higher than the values obtained during the placebo challenge. Inhalation challenge with bleach elicited two isolated late asthmatic reactions and one dual asthmatic reaction. Of all the patients who underwent challenge testing with bleach, only one had a ≥2-fold decrease in methacholine PC(20) 24 hr after the challenge. No significant correlation was found between maximum fall in FEV(1) and PC(20) methacholine. Following challenge testing with bleach, no clinically significant changes in sputum cell counts or FENO were detected.

CONCLUSIONS

These results suggest that bleach inhalation at a concentration of 0.4 ppm-a concentration below 8-hr permissible occupational exposure level-brings about a substantial decrease in FEV1 in subjects with and without BHR. Some subjects have a positive challenge response to bleach inhalation.

The Effect of Exposure to Low Levels of Chlorine Gas on the Pulmonary Function and Symptoms in a Chloralkali Unit

BACKGROUND

The present study was undertaken to ascertain whether (or not) long term occupational exposure to low (sub-TLV levels) atmospheric concentrations of chlorine gas was associated with any significant decrements in the parameters of pulmonary function and/or  increased prevalence of respiratory symptoms.

METHODS

In this retrospective cohort study that was performed in 2012, 54 workers of a local chloralkali unit and 38 non-exposed office staff were enrolled and compared. Atmospheric concentrations of chlorine gas were measured by numerous sampling with gas detector tubes. Data on respiratory symptoms were gathered using a standard questionnaire. Furthermore, spirometry test was performed for subjects both prior to and at the end of shift.

RESULTS

Mean atmospheric concentration of chlorine gas was 0.27 ±0.05 ppm that was lower than the existing TLV value for this toxic irritant gas. Symptoms of respiratory diseases were significantly more frequent among exposed subjects than in referent individuals. Additionally, mean values of most parameters of pulmonary function including FEV1 (P=0.031), FEV1/FVC ratio (P=0.003) and PEF (P=0.005) were significantly lower than their corresponding values for unexposed subjects. Additional cross shift decrements were also noted in some lung functional capacities, although changes were not statistically significant.

CONCLUSIONS

Exposure to sub-TLV levels of chlorine gas is associated with statistically significant decrements in the parameters of pulmonary function as well as increased prevalence of respiratory symptoms.

Occupational asthma in professional cleaning work: a clinical study

BACKGROUND

Several epidemiological studies have reported an increased risk of asthma among professional cleaners. To date, however, no analysis of large patient series from clinic of occupational medicine has been published.

AIMS

To describe the cases of occupational asthma (OA) diagnosed at the Finnish Institute of Occupational Health (FIOH) during the period 1994-2004 in workers employed in professional cleaning work.

METHODS

OA was diagnosed according to patient history, lung function examinations and specific challenge tests with measurements of the forced expiratory volume in 1 second and peak expiratory flow values.

RESULTS

Our series comprised 20 patients, all female, with a mean age of 48.8 years (range 27-60 years). The mean duration of cleaning work before the onset of the respiratory symptoms was 14.3 years (range 1-36 years), and the mean duration of cleaning work before the FIOH examinations was 18.6 years (range 3-38 years). OA was triggered by chemicals in 9 cases (45%) and by moulds in 11 cases (55%). The chemicals were cleaning chemicals (wax-removing substances containing ethanolamines in five cases and a cleaning agent containing chloramine-T in one case) and chemicals used in the industrial processes at workplaces (three cases). Of the moulds, the most frequently associated with OA was Aspergillus fumigatus (nine cases).

CONCLUSIONS

OA was attributed not only to cleaning chemicals but also to other chemicals used in work environments. Moulds are presented as a new cause of OA in cleaners.

Sources of propylene glycol and glycol ethers in air at home

Propylene glycol and glycol ether (PGE) in indoor air have recently been associated with asthma and allergies as well as sensitization in children. In this follow-up report, sources of the PGEs in indoor air were investigated in 390 homes of pre-school age children in Sweden. Professional building inspectors examined each home for water damages, mold odour, building’s structural characteristics, indoor temperature, absolute humidity and air exchange rate. They also collected air and dust samples. The samples were analyzed for four groups of volatile organic compounds (VOCs) and semi-VOCs (SVOCs), including summed concentrations of 16 PGEs, 8 terpene hydrocarbons, 2 Texanols, and the phthalates n-butyl benzyl phthalate (BBzP), and di(2-ethylhexyl)phthalate (DEHP). Home cleaning with water and mop ≥ once/month, repainting ≥ one room prior to or following the child’s birth, and “newest” surface material in the child’s bedroom explained largest portion of total variability in PGE concentrations. High excess indoor humidity (g/m³) additionally contributed to a sustained PGE levels in indoor air far beyond several months following the paint application. No behavioral or building structural factors, except for water-based cleaning, predicted an elevated terpene level in air. No significant predictor of Texanols emerged from our analysis. Overall disparate sources and low correlations among the PGEs, terpenes, Texanols, and the phthalates further confirm the lack of confounding in the analysis reporting the associations of the PGE and the diagnoses of asthma, rhinitis, and eczema, respectively.

Quantitative assessment of airborne exposures generated during common cleaning tasks: a pilot study

BACKGROUND

A growing body of epidemiologic evidence suggests an association between exposure to cleaning products with asthma and other respiratory disorders. Thus far, these studies have conducted only limited quantitative exposure assessments. Exposures from cleaning products are difficult to measure because they are complex mixtures of chemicals with a range of physicochemical properties, thus requiring multiple measurement techniques. We conducted a pilot exposure assessment study to identify methods for assessing short term, task-based airborne exposures and to quantitatively evaluate airborne exposures associated with cleaning tasks simulated under controlled work environment conditions.

METHODS

Sink, mirror, and toilet bowl cleaning tasks were simulated in a large ventilated bathroom and a small unventilated bathroom using a general purpose, a glass, and a bathroom cleaner. All tasks were performed for 10 minutes. Airborne total volatile organic compounds (TVOC) generated during the tasks were measured using a direct reading instrument (DRI) with a photo ionization detector. Volatile organic ingredients of the cleaning mixtures were assessed utilizing an integrated sampling and analytic method, EPA TO-17. Ammonia air concentrations were also measured with an electrochemical sensor embedded in the DRI.

RESULTS

Average TVOC concentrations calculated for 10 minute tasks ranged 0.02 - 6.49 ppm and the highest peak concentrations observed ranged 0.14-11 ppm. TVOC time concentration profiles indicated that exposures above background level remained present for about 20 minutes after cessation of the tasks. Among several targeted VOC compounds from cleaning mixtures, only 2-BE was detectable with the EPA method. The ten minute average 2- BE concentrations ranged 0.30 -21 ppm between tasks. The DRI underestimated 2-BE exposures compared to the results from the integrated method. The highest concentration of ammonia of 2.8 ppm occurred during mirror cleaning.

CONCLUSIONS

Our results indicate that airborne exposures from short-term cleaning tasks can remain in the air even after tasks' cessation, suggesting potential exposures to anyone entering the room shortly after cleaning. Additionally, 2-BE concentrations from cleaning could approach occupational exposure limits and warrant further investigation. Measurement methods applied in this study can be useful for workplace assessment of airborne exposures during cleaning, if the limitations identified here are addressed.

Photovoice in the workplace: A participatory method to give voice to workers to identify health and safety hazards and promote workplace change-a study of university custodians

BACKGROUND

Photovoice, a photographic participatory action research methodology was used in a workplace setting to assess hazards that were creating extremely high injury and incidents rates for university custodians and to promote the conditions to eliminate or reduce those hazards.

METHODS

University custodians participated in a Photovoice project to identify, categorize, and prioritize occupational hazards and to discuss and propose solutions to these problems. Results were presented to management and to all custodians for further discussion. The effort was led by a worker-based union-sponsored participatory evaluation team in partnership with a university researcher.

RESULTS

Visual depiction of hazardous tasks and exposures among custodians and management focused primarily on improper or unsafe equipment, awkward postures, lifting hazards, and electrical hazards. The process of taking pictures and presenting them created an ongoing discussion among workers and management regarding the need for change and for process improvements, and resulted in greater interest and activity regarding occupational health among the workers. In a follow-up evaluation 1-year later, a number of hazards identified through Photovoice had been corrected. Injury rates for custodians had decreased from 39% to 26%.

CONCLUSIONS

Photovoice can be an important tool, not just for identifying occupational hazards, but also empowering workers to be more active around health and safety and may facilitate important changes in the workplace.

Sensory detection and responses to toxic gases: mechanisms, health effects, and countermeasures

The inhalation of reactive gases and vapors can lead to severe damage of the airways and lung, compromising the function of the respiratory system. Exposures to oxidizing, electrophilic, acidic, or basic gases frequently occur in occupational and ambient environments. Corrosive gases and vapors such as chlorine, phosgene, and chloropicrin were used as warfare agents and in terrorist acts. Chemical airway exposures are detected by the olfactory, gustatory, and nociceptive sensory systems that initiate protective physiological and behavioral responses. This review focuses on the role of airway nociceptive sensory neurons in chemical sensing and discusses the recent discovery of neuronal receptors for reactive chemicals. Using physiological, imaging, and genetic approaches, Transient Receptor Potential (TRP) ion channels in sensory neurons were shown to respond to a wide range of noxious chemical stimuli, initiating pain, respiratory depression, cough, glandular secretions, and other protective responses. TRPA1, a TRP ion channel expressed in chemosensory C-fibers, is activated by almost all oxidizing and electrophilic chemicals, including chlorine, acrolein, tear gas agents, and methyl isocyanate, the highly noxious chemical released in the Bhopal disaster. Chemicals likely activate TRPA1 through covalent protein modification. Animal studies using TRPA1 antagonists or TRPA1-deficient mice confirmed the role of TRPA1 in chemically induced respiratory reflexes, pain, and inflammation in vivo. New research shows that sensory neurons are not merely passive sensors of chemical exposures. Sensory channels such as TRPA1 are essential for maintenance of airway inflammation in asthma and may contribute to the progression of airway injury following high-level chemical exposures.

Non-cancer effects of formaldehyde and relevance for setting an indoor air guideline

There is considerable recent focus and concern about formaldehyde (FA). We have reviewed the literature on FA with focus on chemosensory perception in the airways and lung effects in indoor environments. Concentrations of FA, both personal and stationary, are on average in the order of 0.05 mg/m(3) or less in Europe and North America with the exception of new housing or buildings with extensive wooden surfaces, where the concentration may exceed 0.1 mg/m(3). With the eye the most sensitive organ, subjective irritation is reported at 0.3-0.5 mg/m(3), which is somewhat higher than reported odour thresholds. Objective effects in the eyes and airways occur around 0.6-1 mg/m(3). Dose-response relationships between FA and lung function effects have not been found in controlled human exposure studies below 1 mg/m(3), and epidemiological associations between FA concentrations and exacerbation of asthma in children and adults are encumbered by complex exposures. Neither experimental nor epidemiological studies point to major differences in susceptibility to FA among children, elderly, and asthmatics. People with personal trait of negative affectivity may report more symptoms. An air quality guideline of 0.1 mg/m(3) (0.08 ppm) is considered protective against both acute and chronic sensory irritation in the airways in the general population assuming a log normal distribution of nasal sensory irritation.

Incidence and prevalence of adult asthma is associated with low socio-economic status

BACKGROUND

Low socio-economic status is often related to health problems; however, previous studies on asthma, usually cross-sectional, yield inconsistent results. In this study, longitudinal and cross-sectional data on the association between socio-economic status and asthma as well as respiratory symptoms among adults are presented.

METHODS

A postal questionnaire was sent on two occasions, 1996 and 2006, to a randomly selected sample of subjects aged 20-69 years in 1996. In total, 4479 subjects participated in both surveys. The questionnaire included questions on asthma, respiratory symptoms and possible determinants. Logistic regression analysis, adjusted for potential confounders, was used to study the association between asthma, respiratory symptoms and socio-economic status.

RESULTS

Manual workers in service had the highest prevalence and cumulative incidence for all investigated symptoms and asthma. Despite a large decrease in smokers, the increase in incident bronchitic symptoms was higher than the increase of incident asthma and incident asthmatic symptoms. Low socio-economic status, rhinitis and a family history of asthma were risk factors for having and developing asthma and respiratory symptoms.

CONCLUSION

Low socio-economic status is significantly associated with an increased risk for prevalent and incident asthma and respiratory symptoms in this longitudinal population-based survey. The increase in risk was most pronounced in manual workers. Several studies have recently shown an association between low socio-economic status and respiratory symptoms and we conclude that asthma can not be considered as a disease that mainly affects the middle and upper socio-economic classes.

Risks of exposure to occupational asthmogens in atopic and nonatopic asthma: a case-control study in Taiwan

RATIONALE

Asthma is often work-related and can be classified as atopic or nonatopic on the basis of its pathogenesis. Few studies have reported an association between exposure to occupational asthmogens and asthma with and without atopy.

OBJECTIVES

We investigated, in adults with asthma, whether occupational exposure to asthmogens influenced the risk of having atopic or nonatopic asthma, and their level of lung function.

METHODS

We recruited 504 hospital-based adults with current asthma, 504 community-based control subjects, and 504 hospital-based control subjects in southern Taiwan. Asthma with atopy was defined as having asthma in combination with an increase in total IgE (≥100 U/ml) or a positive Phadiatop test (≥0.35 Pharmacia arbitrary unit/L) (Pharmacia ImmunoCAP; Pharmacia, Uppsala, Sweden). Occupational exposure to asthmogens was assessed with an asthma-specific job exposure matrix.

MEASUREMENTS AND MAIN RESULTS

We found a significant association between atopic asthma and exposure to high molecular weight asthmogens (adjusted odds ratio [AOR], 4.0; 95% confidence interval [CI], 1.8-8.9). Nonatopic asthma was significantly associated with exposure to low molecular weight asthmogens (AOR, 2.6; 95% CI, 1.6-4.3), including industrial cleaning agents and metal sensitizers. Agriculture was associated with both atopic and nonatopic asthma (AOR, 7.8; 95% CI, 2.8-21.8; and AOR, 4.1; 95% CI, 1.3-13.0, respectively). The ratio of FEV₁ to FVC in the high-risk group was significantly lower than in the no-risk group (P = 0.026) in currently employed patients with asthma.

CONCLUSIONS

In adults with asthma, occupational exposure to high and low molecular weight asthmogens appears to produce differential risks for atopic and nonatopic asthma.

An assessment of the ability of phthalates to influence immune and allergic responses

It has been suggested that one possible contributor to the increasing prevalence of atopic (IgE-mediated) allergic diseases and asthma in Europe and the US is exposure to chemicals that may act as adjuvants. Certain commonly used phthalate plasticisers, such as di-(2-ethylhexyl) phthalate, have been implicated in this regard. The evidence for the ability of phthalates to impact on immune and allergic responses has been examined, encompassing epidemiological investigations and results deriving from studies using experimental animals and from analyses in vitro. The epidemiological data provide some evidence that exposure to phthalates may be associated with increased risk of development of allergies and asthma, however, the lack of objective exposure information limits the interpretation. A variety of studies have been performed in mice to examine the influence of phthalate (delivered via various routes of exposure) to impact on immune responses. Measurement of antibody responses is the commonest read out, although other parameters of inflammation such as eosinophil infiltration and cytokine production have been used also. Although certain phthalates, when delivered at appropriate doses, and via an appropriate route, have been reported to impact on immune and inflammatory function in rodents, as yet no consistent pattern has emerged. Results ranged from potentiation of immune or inflammatory responses, to the absence of any effect, to inhibitory or immunosuppressive activity. In addition, comparatively low doses of phthalates have been associated with immune effects only when routes of administration (subcutaneous or intraperitoneal) are used that do not reflect, and are much less relevant for, opportunities for human contact with phthalates. There is clearly a case to be made for the design of more definitive animal studies that will allow development of a more detailed understanding of whether and to what extent, and under what conditions, phthalates are able to effect meaningful changes in immune function that may in turn impact on human health.

Invisible work, unseen hazards: The health of women immigrant household service workers in Spain

BACKGROUND

Household service work has been largely absent from occupational health studies. We examine the occupational hazards and health effects identified by immigrant women household service workers.

METHODS

Exploratory, descriptive study of 46 documented and undocumented immigrant women in household services in Spain, using a phenomenological approach. Data were collected between September 2006 and May 2007 through focus groups and semi-structured individual interviews. Data were separated for analysis by documentation status and sorted using a mixed-generation process. In a second phase of analysis, data on psychosocial hazards were organized using the Copenhagen Psychosocial Questionnaire as a guide.

RESULTS

Informants reported a number of environmental, ergonomic and psychosocial hazards and corresponding health effects. Psychosocial hazards were especially strongly present in data. Data on reported hazards were similar by documentation status and varied by several emerging categories: whether participants were primarily cleaners or carers and whether they lived in or outside of the homes of their employers. Documentation status was relevant in terms of empowerment and bargaining, but did not appear to influence work tasks or exposure to hazards directly.

CONCLUSIONS

Female immigrant household service workers are exposed to a variety of health hazards that could be acted upon by improved legislation, enforcement, and preventive workplace measures, which are discussed.

The Vida Verde Women's Co-Op: Brazilian immigrants organizing to promote environmental and social justice

We reviewed the key steps in the launch of the Vida Verde Women's Co-Op among Brazilian immigrant housecleaners in Somerville, MA. The co-op provides green housecleaning products, encourages healthy work practices, and promotes a sense of community among its members. We conducted in-depth interviews with 8 of the first co-op members, who reported a reduction in symptoms associated with the use of traditional cleaning agents and a new sense of mutual support. Critical to the co-op's success have been the supportive roles of its academic partners (Tufts University and the University of Massachusetts, Lowell), effective media outreach, and a focus on advancing social justice. Next steps include implementing a formal business plan and assessing the appropriateness of cooperatives in other industries.

Chemical pneumonitis and subsequent reactive airways dysfunction syndrome after a single exposure to a household product: a case report

INTRODUCTION

Household products are usually safe to use. Adverse events arising from their use are mostly reported in patients with pre-existing atopy or pulmonary problems and usually only after a prolonged exposure to such products. We report the case of a patient with no prior problems who developed significant side effects from a single exposure to a domestic product.

CASE PRESENTATION

A 43-year-old Caucasian American man, previously in good health, used a domestic aerosol product called 'Stand N' Seal "Spray-On" Grout Sealer' in an enclosed room in his house. The product contained n-butyl acetate (<5%), propane (10%), isobutane (<5%), C8-C9 petroleum hydrocarbon solvent (80%), a fluoropolymer resin and a solvent. Within a few hours of exposure to the sealant, he developed rapidly progressive shortness of breath and a severe non-productive cough. By the time he reached the emergency room he was severely hypoxic. A diagnosis of chemical pneumonitis was made based on the clinical scenario and the diffuse infiltrates on the computer tomography scan. With supportive therapy, his condition improved and he was discharged from the hospital. However, he continued to have symptoms of intermittent cough and shortness of breath in response to strong odours, fumes, cold air and exertion even after his chest radiograph had normalized. Three months later, bronchial hyper-responsiveness was documented by a methacholine inhalation test and a diagnosis of reactive airways dysfunction syndrome was made. The patient was started on high-dose inhaled steroids and his symptoms improved. The mechanism of toxicity and determination of the exact agent responsible is still under investigation.

CONCLUSION

A household product may still prove unsafe to use even after it has gone through vigorous testing and approval processes. Even healthy individuals are susceptible to adverse outcomes after a brief exposure. Extra precautions should be taken when using any chemical product at home.

Evaluation of five decontamination methods for filtering facepiece respirators

Concerns have been raised regarding the availability of National Institute for Occupational Safety and Health (NIOSH)-certified N95 filtering facepiece respirators (FFRs) during an influenza pandemic. One possible strategy to mitigate a respirator shortage is to reuse FFRs following a biological decontamination process to render infectious material on the FFR inactive. However, little data exist on the effects of decontamination methods on respirator integrity and performance. This study evaluated five decontamination methods [ultraviolet germicidal irradiation (UVGI), ethylene oxide, vaporized hydrogen peroxide (VHP), microwave oven irradiation, and bleach] using nine models of NIOSH-certified respirators (three models each of N95 FFRs, surgical N95 respirators, and P100 FFRs) to determine which methods should be considered for future research studies. Following treatment by each decontamination method, the FFRs were evaluated for changes in physical appearance, odor, and laboratory performance (filter aerosol penetration and filter airflow resistance). Additional experiments (dry heat laboratory oven exposures, off-gassing, and FFR hydrophobicity) were subsequently conducted to better understand material properties and possible health risks to the respirator user following decontamination. However, this study did not assess the efficiency of the decontamination methods to inactivate viable microorganisms. Microwave oven irradiation melted samples from two FFR models. The remainder of the FFR samples that had been decontaminated had expected levels of filter aerosol penetration and filter airflow resistance. The scent of bleach remained noticeable following overnight drying and low levels of chlorine gas were found to off-gas from bleach-decontaminated FFRs when rehydrated with deionized water. UVGI, ethylene oxide (EtO), and VHP were found to be the most promising decontamination methods; however, concerns remain about the throughput capabilities for EtO and VHP. Further research is needed before any specific decontamination methods can be recommended.

Relationships between asthma and work exposures among non-domestic cleaners in Ontario

BACKGROUND

Cleaners have been reported to have increased risk for work-related asthma symptoms but few studies have studied non-domestic cleaners. In this study, we compared work-related asthma symptoms among cleaners and other building workers and determined associations with tasks.

METHODS

School and racetrack workers in Ontario, Canada, completed a questionnaire to identify the prevalence of cleaning tasks, physician-diagnosed asthma, new-onset asthma, respiratory symptoms, and work-related asthma symptoms.

RESULTS

Cleaners and controls had a similar prevalence of most asthma outcomes although female cleaners reported significantly more respiratory symptoms; odds ratio (OR), 2.59 confidence intervals (CI) 1.6-4.3, and work-related asthma symptoms, OR 3.90 (CI 2.1-7.4) compared with female controls with adjustment for age and smoking history. Male cleaners showed a non-significant trend to more physician-diagnosed asthma, adjusted OR 2.10 (CI 0.9-4.8) and work-related asthma symptoms, adjusted OR 1.53 (CI 0.8-3.0). The work-related asthma symptoms among men were significantly associated with waxing floors, OR 2.19 (CI 1.0-4.4); wax-stripping floors, OR 2.54 (1.2-5.2); spot-cleaning carpets, OR 2.20 (1.3-3.8); and cleaning tiles, OR 4.46 (1.0-19.3) and grout, OR 2.12 (1.1-4.0).

CONCLUSIONS

Female cleaners have more asthma symptoms worse at work than controls. Work-related asthma symptoms among male cleaners were associated with a number of specific cleaning tasks. Findings suggest the need for school cleaners to have reduced exposure to cleaning chemicals and need for protective strategies during performance of tasks expected to exacerbate asthma, such as wax stripping.

Reducing hazardous cleaning product use: a collaborative effort

Workplace hazards affecting vulnerable populations of low-wage and immigrant workers present a special challenge to the practice of occupational health. Unions, Coalition for Occupational Safety and Health (COSH) groups, and other organizations have developed worker-led approaches to promoting safety. Public health practitioners can provide support for these efforts. This article describes a successful multiyear project led by immigrant cleaning workers with their union, the Service Employees International Union (SEIU) Local 615, and with support from the Massachusetts COSH (MassCOSH) to address exposure to hazardous chemicals. After the union had identified key issues and built a strategy, the union and MassCOSH invited staff from the Massachusetts Department of Public Health's Occupational Health Surveillance Program (OHSP) to provide technical information about health effects and preventive measures. Results included eliminating the most hazardous chemicals, reducing the number of products used, banning mixing products, and improving safety training. OHSP's history of public health practice regarding cleaning products enabled staff to respond promptly. MassCOSH's staff expertise and commitment to immigrant workers allowed it to play a vital role.

Cutaneous and respiratory symptoms among professional cleaners

BACKGROUND

Occupational dermatitis is very common and has a large economic impact. Cleaners are at an increased risk for both work-related cutaneous and respiratory symptoms.

AIMS

To compare the prevalence of occupational cutaneous symptoms among professional indoor cleaners to other building workers (OBW) and to determine associations with exposures and with respiratory symptoms among cleaners.

METHODS

A questionnaire completed by indoor professional cleaners and OBW to compare rash and respiratory symptoms between these groups examined workplace factors such as training, protective equipment and work tasks.

RESULTS

In total, 549 of the 1396 professional cleaners (39%) and 593 of the 1271 OBW (47%) completed questionnaires. The prevalence of rash was significantly higher in the cleaners compared to the OBW. For male cleaners, 21% (86/413) had a rash in the past 12 months compared to only 11% (13/115) of OBW (P < 0.05). The rashes experienced by the cleaners were more likely to be on their hands and worse at work. Cleaners washed their hands significantly more often than OBW. Cleaners with a rash were less likely to have received workplace training regarding their skin and were more likely to find the safety training hard to understand. Cleaners with a rash within the past year were significantly more likely to have work-related asthma symptoms than cleaners without a rash (P < 0.001).

CONCLUSIONS

This study demonstrates a strong link between work-related symptoms of asthma and dermatitis among cleaners. Effective preventive measures, such as the use of protective skin and respiratory equipment, should be emphasized.

Childhood asthma and environmental exposures at swimming pools: state of the science and research recommendations

OBJECTIVES

Recent studies have explored the potential for swimming pool disinfection by-products (DBPs), which are respiratory irritants, to cause asthma in young children. Here we describe the state of the science on methods for understanding children's exposure to DBPs and biologics at swimming pools and associations with new-onset childhood asthma and recommend a research agenda to improve our understanding of this issue.

DATA SOURCES

A workshop was held in Leuven, Belgium, 21-23 August 2007, to evaluate the literature and to develop a research agenda to better understand children's exposures in the swimming pool environment and their potential associations with new-onset asthma. Participants, including clinicians, epidemiologists, exposure scientists, pool operations experts, and chemists, reviewed the literature, prepared background summaries, and held extensive discussions on the relevant published studies, knowledge of asthma characterization and exposures at swimming pools, and epidemiologic study designs.

SYNTHESIS

Childhood swimming and new-onset childhood asthma have clear implications for public health. If attendance at indoor pools increases risk of childhood asthma, then concerns are warranted and action is necessary. If there is no such relationship, these concerns could unnecessarily deter children from indoor swimming and/or compromise water disinfection.

CONCLUSIONS

Current evidence of an association between childhood swimming and new-onset asthma is suggestive but not conclusive. Important data gaps need to be filled, particularly in exposure assessment and characterization of asthma in the very young. Participants recommended that additional evaluations using a multidisciplinary approach are needed to determine whether a clear association exists.

Characterization of occupational exposures to cleaning products used for common cleaning tasks--a pilot study of hospital cleaners

BACKGROUND

In recent years, cleaning has been identified as an occupational risk because of an increased incidence of reported respiratory effects, such as asthma and asthma-like symptoms among cleaning workers. Due to the lack of systematic occupational hygiene analyses and workplace exposure data, it is not clear which cleaning-related exposures induce or aggravate asthma and other respiratory effects. Currently, there is a need for systematic evaluation of cleaning products ingredients and their exposures in the workplace. The objectives of this work were to: a) identify cleaning products' ingredients of concern with respect to respiratory and skin irritation and sensitization; and b) assess the potential for inhalation and dermal exposures to these ingredients during common cleaning tasks.

METHODS

We prioritized ingredients of concern in cleaning products commonly used in several hospitals in Massachusetts. Methods included workplace interviews, reviews of product Materials Safety Data Sheets and the scientific literature on adverse health effects to humans, reviews of physico-chemical properties of cleaning ingredients, and occupational hygiene observational analyses. Furthermore, the potential for exposure in the workplace was assessed by conducting qualitative assessment of airborne exposures and semi-quantitative assessment of dermal exposures.

RESULTS

Cleaning products used for common cleaning tasks were mixtures of many chemicals, including respiratory and dermal irritants and sensitizers. Examples of ingredients of concern include quaternary ammonium compounds, 2-butoxyethanol, and ethanolamines. Cleaning workers are at risk of acute and chronic inhalation exposures to volatile organic compounds (VOC) vapors and aerosols generated from product spraying, and dermal exposures mostly through hands.

CONCLUSION

Cleaning products are mixtures of many chemical ingredients that may impact workers' health through air and dermal exposures. Because cleaning exposures are a function of product formulations and product application procedures, a combination of product evaluation with workplace exposure assessment is critical in developing strategies for protecting workers from cleaning hazards. Our task based assessment methods allowed classification of tasks in different exposure categories, a strategy that can be employed by epidemiological investigations related to cleaning. The methods presented here can be used by occupational and environmental health practitioners to identify intervention strategies.

Agents causing occupational asthma

The workplace is a significant contributor to the burden of asthma. Although the majority of cases probably represent what is labeled work-exacerbated asthma, in a significant number of subjects, asthma is actually caused by 1 or more agents present in the workplace; this is occupational asthma. Two types of occupational asthma are distinguished, according to whether the asthma appears after a latency period. This article discusses (1) two types of agents causing asthma with a latency period and acting through an apparently immunologic mechanism (high-molecular-weight agents and low-molecular-weight agents) and (2) agents causing asthma without a latency period.

Occupational exposures and adult asthma

Occupational exposures can cause a new onset of asthma in a subset of susceptible workers on the basis of sensitization to a specific work agent or a high-level irritant exposure. Epidemiologic studies give insight into the natural history of occupational asthma, including host factors and environmental factors leading to the development of occupational asthma, the progression, and the potential role of preventive measures. Work-exacerbated asthma has been a focus of studies only recently but is recognized as common among asthmatic workers and is a potential cause of significant morbidity and socioeconomic impact.

Five annual observations of respiratory findings in gun factory workers exposed to solvents

OBJECTIVE

We investigated whether long-term, low-level exposures to solvents had adverse longitudinal effects on pulmonary functions.

METHODS

The study was performed on 1091 workers 5 years ago and then on 697 workers 5 years later. Chronic respiratory symptoms were recorded using a questionnaire on respiratory symptoms.

RESULTS

The annual decrease in forced expiratory volume in 1 second in the workers exposed to solvents was not significantly different from that of the unexposed workers (69.7 +/- 89.9 vs 75.8 +/- 87.6 mL/yr, P = 0.5, respectively). In 453 workers who were exposed to solvents 5 years ago, the prevalence rate of asthma was 1.1%. Five years later, it was 3.6% in 193 workers from the same group. The difference was statistically significant (P = 0.03).

CONCLUSIONS

Longitudinally, the chronic exposure to low doses of solvents does not adversely affect the pulmonary functions, whereas it increases the asthma prevalence.

Chemical pollution, respiratory allergy and asthma: a perspective

The European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) convened a workshop in June 2005 to address the speculation that exposure to specific chemicals, and/or chemical pollutants in general, may play an important role in the increased prevalence of allergy and asthma in 'westernized' societies. This paper summarises one perspective arrived at during this workshop. It was acknowledged that certain chemicals and certain types of pollution might trigger or exacerbate asthmatic reactions in sensitised subjects. However, overall levels of pollution appear not to have had a major impact upon the prevalence of atopic allergy. Epidemiological studies suggest that pollution may in some circumstances protect from acquisition of sensitisation. Increasing exposure to household chemicals may enhance pre-existing allergies, but evidence for their causation of allergy is lacking. Other risk factors considered included societal dietary changes and exposure to endotoxins. Future research needs were identified which included epidemiological studies employing exposure and biomonitoring data, studies on domestic exposure to chemicals and their association with the incidence of allergy and asthma, and prospective birth cohort studies employing well-defined aspects of lifestyle, diet, chemical and endotoxin exposure as factors that may drive susceptibility to allergy and asthma.

Atopy, symptoms and indoor environmental perceptions, tear film stability, nasal patency and lavage biomarkers in university staff

OBJECTIVE

Study associations between airway symptoms, complaints on environmental perceptions, atopy definitions and biomarkers including tear film stability (BUT), nasal patency and nasal lavage (NAL). Personal predictors (gender, age, smoking, infections) for the biomarkers as well as associations between the biomarkers were also assessed.

METHODS

A cross-sectional study of 173 employees in four university buildings, response rate 86%. Tear film break up time (BUT) was measured by a non-invasive method (NIBUT) and self-reported (SBUT). NAL-analysis included eosinophilic cationic protein (ECP), myeloperoxidase (MPO), lysozyme and albumin. Total serum IgE, and specific IgE using Phadiatop was measured. Data on subjective symptoms, environmental perceptions and background data were collected by use of a questionnaire. Multiple regression analyses were applied.

RESULTS

Mean age was 43 years, 21% had weekly ocular, 21% nasal, and 17% laryngeal symptoms. Women had more complaints on environmental perceptions, shorter BUT and less nasal patency. Neither atopy (Phadiatop) nor Total IgE or allergy in the family, but asthma and hay fever was associated with mucosal symptoms or perceptions. Subjects with positive Phadiatop had higher levels of all NAL-biomarkers. Those with ocular symptoms had shorter BUT. Nasal symptoms were related to respiratory infections and laryngeal symptoms to NAL-lysozyme. Perceiving dry air was associated with lower BUT and reduced nasal volume difference before and after decongestion. Older subjects had greater nasal patency, and less atopy. All NAL-biomarkers were positively correlated. Higher lysozyme level was associated with less nasal patency and greater nasal decongestion.

CONCLUSIONS

BUT and NAL-lysozyme was associated with ocular, nasal, laryngeal symptoms and indoor environmental perceptions. Ever having had asthma and ever having had hay fever were predictors for symptoms and perceived air quality, respectively. Phadiatop, Total IgE, familiar allergy and ever eczema were not associated to symptoms or perceived environments. Age, gender and Phadiatop were main predictors for ocular and nasal biomarkers.

Storage and utilization patterns of cleaning products in the home: toxicity implications

BACKGROUND AND AIMS

Cleaning products are used to achieve cleaner homes. However, they have been responsible for a considerable number of poisoning cases. The aims of this study were to investigate the storage and utilization patterns of cleaning products in the home, as well as the risk of adverse and toxic effects produced by them.

METHODS

This study has been performed using a questionnaire that was developed by the Poison Control and Drug Information Center (PCDIC). The questionnaire was distributed randomly in northern Palestine. The questionnaire included questions regarding storage, utilization habits, and the adverse effects experienced by respondents upon handling the cleaning products.

RESULTS

All respondents utilized and stored cleaning products in their homes. Chlorine bleach and acidic cleaning products were the most common. Respondents stored cleaning products at different places in their homes, but most of those storage places were suboptimal and were within the reach of children. The daily utilization rate of cleaning products was 1.6+/-0.8 with chlorine bleach being the most commonly used. Of the respondents, 27% reported experiencing a wide range of acute adverse and toxic effects resulting from cleaning product use and that exposure occurred mainly via inhalation. Caustic substances, bleach, and kerosene were the agents mainly involved in producing these adverse and toxic effects. About half of those who experienced adverse and toxic effects sought medical help, and 22% of them were children younger than 6 years of age. Finally, most respondents reported mixing and discarding cleaning product leftovers and their containers improperly.

CONCLUSION AND RECOMMENDATIONS

Correct utilization and safer storage of cleaning products is encouraged. Several preventive strategies should be implemented in order to decrease the incidence of accidental harmful exposure that is due to cleaning agents. The role of the PCDIC is very important in the education, prevention, and management of cleaning product-induced adverse effects.

Exposure to substances in the workplace and new-onset asthma: an international prospective population-based study (ECRHS-II)

BACKGROUND

The role of exposure to substances in the workplace in new-onset asthma is not well characterised in population-based studies. We therefore aimed to estimate the relative and attributable risks of new-onset asthma in relation to occupations, work-related exposures, and inhalation accidents.

METHODS

We studied prospectively 6837 participants from 13 countries who previously took part in the European Community Respiratory Health Survey (1990-95) and did not report respiratory symptoms or a history of asthma at the time of the first study. Asthma was assessed by methacholine challenge test and by questionnaire data on asthma symptoms. Exposures were defined by high-risk occupations, an asthma-specific job exposure matrix with additional expert judgment, and through self-report of acute inhalation events. Relative risks for new onset asthma were calculated with log-binomial models adjusted for age, sex, smoking, and study centre.

FINDINGS

A significant excess asthma risk was seen after exposure to substances known to cause occupational asthma (Relative risk=1.6, 95% CI 1.1-2.3, p=0.017). Risks were highest for asthma defined by bronchial hyper-reactivity in addition to symptoms (2.4, 1.3-4.6, p=0.008). Of common occupations, a significant excess risk of asthma was seen for nursing (2.2, 1.3-4.0, p=0.007). Asthma risk was also increased in participants who reported an acute symptomatic inhalation event such as fire, mixing cleaning products, or chemical spills (RR=3.3, 95% CI 1.0-11.1, p=0.051). The population-attributable risk for adult asthma due to occupational exposures ranged from 10% to 25%, equivalent to an incidence of new-onset occupational asthma of 250-300 cases per million people per year.

INTERPRETATION

Occupational exposures account for a substantial proportion of adult asthma incidence. The increased risk of asthma after inhalation accidents suggests that workers who have such accidents should be monitored closely.

Chronic bronchitis among nonsmoking farm women in the agricultural health study

OBJECTIVE

The purpose of this study was to examine agricultural risk factors for chronic bronchitis among nonsmoking farm women.

METHODS

We used self-reported enrollment data from the 21,541 nonsmoking women in the Agricultural Health Study to evaluate occupational risk factors for prevalent chronic bronchitis among farm women. Odds ratios (ORs) for chronic bronchitis for occupational exposures were adjusted for age, state, and related agricultural exposures.

RESULTS

Applying manure and driving combines were independently associated with chronic bronchitis. Off-farm job exposures associated with chronic bronchitis were organic dusts, asbestos, gasoline, and solvents. Five pesticides were associated with chronic bronchitis after multivariate adjustment and sensitivity analyses: dichlorvos (OR=1.63, 95% CI=1.01, 2.61), DDT (OR=1.67, 95% CI=1.13, 2.47), cyanazine (OR=1.88, 95% CI=1.00, 3.54), paraquat (OR=1.91, 95% CI=1.02, 3.55), and methyl bromide (OR=1.82, 95% CI=1.02, 3.24).

CONCLUSION

Pesticides as well as grain and dust exposures were associated with chronic bronchitis among nonsmoking farm women.

Rhinitis and asthma symptoms in non-domestic cleaners from the Sao Paulo metropolitan area, Brazil

BACKGROUND

Exposure to cleaning products has frequently been reported as a symptom trigger by workers with work-related asthma diagnosed in workers' health clinics in the city of São Paulo, Brazil.

OBJECTIVES

To estimate rhinitis and asthma symptoms prevalence and to analyse associated risk factors.

METHOD

A respiratory symptoms questionnaire (Medical Research Council 1976) and the International Study of Asthma and Allergies in Childhood questionnaire were applied to 341 cleaners working in the city of São Paulo, along with obtaining full occupational histories, skin prick tests and spirometry. Timing their symptoms onset in relation to occupational history allowed estimation of work-related asthma and/or rhinitis. Risk factors related to selected outcomes were analysed by logistic regression.

RESULTS

11% and 35% of the cleaners had asthma and rhinitis, respectively. The risk of work-related asthma/rhinitis increased with years of employment in non-domestic cleaning (OR 1.09, 95% CI 1.00 to 1.18, >0.92-3 years; OR 1.28, 95% CI 1.01 to 1.63, >3-6.5 years; OR 1.71, 95% CI 1.02 to 2.89, >6.5 years). Atopy was associated with asthma and rhinitis (OR 2.91, 95% CI 1.36 to 6.71; OR 2.06, 95% CI 1.28 to 3.35, respectively). There was a higher risk of rhinitis in women (OR 2.07, 95% CI 1.20 to 3.70).

CONCLUSIONS

Cleaning workers are at risk of contracting work-related asthma and/or rhinitis, and the risk increases with years of employment in non-domestic cleaning. Women present higher risk of rhinitis than men.

The use of household cleaning sprays and adult asthma: an international longitudinal study

RATIONALE

Cleaning work and professional use of certain cleaning products have been associated with asthma, but respiratory effects of nonprofessional home cleaning have rarely been studied.

OBJECTIVES

To investigate the risk of new-onset asthma in relation to the use of common household cleaners.

METHODS

Within the follow-up of the European Community Respiratory Health Survey in 10 countries, we identified 3,503 persons doing the cleaning in their homes and who were free of asthma at baseline. Frequency of use of 15 types of cleaning products was obtained in a face-to-face interview at follow-up. We studied the incidence of asthma defined as physician diagnosis and as symptoms or medication usage at follow-up. Associations between asthma and the use of cleaning products were evaluated using multivariable Cox proportional hazards or log-binomial regression analysis.

MEASUREMENTS AND MAIN RESULTS

The use of cleaning sprays at least weekly (42% of participants) was associated with the incidence of asthma symptoms or medication (relative risk [RR], 1.49; 95% confidence interval [CI], 1.12-1.99) and wheeze (RR, 1.39; 95% CI, 1.06-1.80). The incidence of physician-diagnosed asthma was higher among those using sprays at least 4 days per week (RR, 2.11; 95% CI, 1.15-3.89). These associations were consistent for subgroups and not modified by atopy. Dose-response relationships (P < 0.05) were apparent for the frequency of use and the number of different sprays. Risks were predominantly found for the commonly used glass-cleaning, furniture, and air-refreshing sprays. Cleaning products not applied in spray form were not associated with asthma.

CONCLUSIONS

Frequent use of common household cleaning sprays may be an important risk factor for adult asthma.

Do indoor chemicals promote development of airway allergy?

Allergic asthma has increased worldwide in the industrialized countries. This review evaluates whether the major groups of indoor chemical exposures possess allergy-promoting (adjuvant) effects; formaldehyde was excluded, because of the size of the literature. Volatile organic compounds (VOCs) are used as an example of gases and vapors. The precipitation of asthmatic symptoms by VOC exposures is probably because of VOC levels considerably above typical indoor levels, or VOCs may be a surrogate for exposure to allergens, combustion products or dampness. Indoor particles possessed adjuvant effects in animal studies and allergy-promoting effects in humans. Quaternary ammonium compounds may possess adjuvant effects in animal studies and promoted sensitization in humans in occupational settings. The use of cleaning agents, anionic and non-ionic surfactants are not considered to possess an important adjuvant effect in the general population. Regarding phthalate exposures, results from animal and epidemiological studies were found to be discordant. There is little evidence that the indoor chemicals evaluated possess important adjuvant effects. If buildings are kept clean, dry and free of combustion products, the important question may be would it be profitable to look for lifestyle factors and non-chemical indoor exposures in order to abate airway allergy?

PRACTICAL IMPLICATIONS

Indoor chemicals (pollutants) have been accused to promote development of airway allergy by adjuvant effects. In this review, we evaluated the scientific literature and found little support for the supposition that indoor chemicals possess important adjuvant effects. This rises the question: would it be profitable for abatement of airway allergy to look for non-chemical indoor exposures, including lifestyle factors, and exposures to allergens, microorganisms, including vira, and their interactions?

New insights into occupational asthma

PURPOSE OF REVIEW

To examine recent publications on the types of agents involved in occupational asthma, the mechanisms by which they induce asthma, and how best to evaluate and treat workers suspected of this respiratory condition.

RECENT FINDINGS

High rates of occupational asthma and inhalation accidents were found in workers in crafts and related occupations in the manufacturing industries, and in plant and machine operatives; cleaners and construction workers may also be at risk. Further data support a role for CD4 T cells in low-molecular-weight agent-induced asthma, such as with isocyanates, and neurogenic mechanisms may also be involved. The use of noninvasive measures of airway inflammation in the diagnosis and management of occupational asthma such as sputum eosinophils monitoring is promising, although this is less obvious for exhaled nitric oxide. Finally, the persistence of troublesome asthma even after withdrawal from relevant exposure has been re-emphasized and surveillance programs have been proposed.

SUMMARY

Further data have been gathered on the prevalence of occupational asthma in various working populations, its mechanisms of development, the contribution of noninvasive measures of airway inflammation in the diagnosis and management of this condition, and its management and prevention.

A multi-faceted approach to risk assessment of laboratory animal allergens at two facilities

BACKGROUND

Risk assessment of exposure to allergens is difficult because the relationship between exposure, sensitization, and symptoms has not been fully established. Laboratory animal allergens (LAA) are an important occupational health risk factor; 10-32% of workers exposed to these allergens develop allergic diseases. This article introduces a versatile approach to assessing the risks posed by LAA at two laboratory animal facilities.

METHODS

The risk assessment approach that was used at the laboratory animal facilities included questionnaires for management and employees, a hazard identification visit and measurements in the workplaces, as well as the creation of a list of generally recommended procedures to reduce allergen exposure.

RESULTS

The prevalence of work-related allergic symptoms was 17%. Suggested countermeasures at the sites included changes in ventilation and work practices, reduction of unnecessary exposure, recommendations for more comprehensive use of personal protective equipment, and wider communication about LAA risks.

CONCLUSIONS

The approach managed to identify critical points and potential means for controlling LAA exposure.

Occupational risk factors and asthma among health care professionals

RATIONALE

Recent U.S. data suggest an increased risk of work-related asthma among health care workers, yet only a few specific determinants have been elucidated.

OBJECTIVES

To evaluate associations of asthma prevalence with occupational exposures in a cross-sectional survey of health care professionals.

METHODS

A detailed questionnaire was mailed to a random sample (n=5,600) of all Texas physicians, nurses, respiratory therapists, and occupational therapists with active licenses in 2003. Information on asthma symptoms and nonoccupational asthma risk factors obtained from the questionnaire was linked to occupational exposures derived through an industry-specific job-exposure matrix.

MEASUREMENTS

There were two a priori defined outcomes: (1) physician-diagnosed asthma with onset after entry into health care ("reported asthma") and (2) "bronchial hyperresponsiveness-related symptoms," defined through an 8-item symptom-based predictor.

MAIN RESULTS

Overall response rate was 66%. The final study population consisted of 862 physicians, 941 nurses, 968 occupational therapists, and 879 respiratory therapists (n=3,650). Reported asthma was associated with medical instrument cleaning (odds ratio [OR], 2.22; 95% confidence interval [CI], 1.34-3.67), general cleaning (OR, 2.02; 95% CI, 1.20-3.40), use of powdered latex gloves between 1992 and 2000 (OR, 2.17; 95% CI, 1.27-3.73), and administration of aerosolized medications (OR, 1.72; 95% CI, 1.05-2.83). The risk associated with latex glove use was not apparent after 2000. Bronchial hyperresponsiveness-related symptoms were associated with general cleaning (OR, 1.63; 95% CI, 1.21-2.19), aerosolized medication administration (OR, 1.40; 95% CI, 1.06-1.84), use of adhesives on patients (OR, 1.65; 95% CI, 1.22-2.24), and exposure to a chemical spill (OR, 2.02; 95% CI, 1.28-3.21).

CONCLUSIONS

The contribution of occupational exposures to asthma in health care professionals is not trivial, meriting both implementation of appropriate controls and further study.

Reducing home triggers for asthma: the Latino community health worker approach

This study assessed the ability of a community health worker asthma intervention to change home asthma triggers. A total of 56 children and 47 adults with asthma were enrolled. Home trigger scores for the children averaged 2.8 at the initial home visit and then 2.3, 2.1, and 2.0 at 3, 6, and 12 months. Home trigger scores for the adults showed a similar trend. Every home visit was associated with a 0.32 reduction in home trigger score (p < 0.01) for children and a 0.41 reduction (p < 0.01) for adults. This intervention shows promise as a way to reduce asthma triggers in urban low-income Latino communities.

Professional cleaning and asthma

PURPOSE OF REVIEW

The purpose of this review is to summarize the recent evidence on the effect of cleaning jobs on asthma, based on case reports and series of occupational asthma among cleaners, and epidemiological studies on the relationship between different characteristics of cleaning and asthma risk, as well as to elaborate the evidence on potential occupational exposures responsible for the increased asthma risk observed in cleaners.

RECENT FINDINGS

Six recent epidemiologic studies strengthen the evidence that domestic and industrial cleaners are at higher risk of asthma compared with professional employees in Europe and the United States. These studies take into account individual confounders, such as age and cigarette smoking. This finding is supported by case reports and registry-based studies of occupational asthma. The studies and reports have identified some chemicals, such as bleach, as specific causes of asthma. Increased risk of asthma has also been related to some specific job tasks, such as cleaning windows and washing dishes.

SUMMARY

Recent studies strengthen the evidence of an increased asthma risk among cleaners or individuals in other jobs in which they are involved in cleaning. Further research should be directed to elaborate how much of asthma is related to specific sensitization to certain chemicals and how much to airway inflammation induced by exposure to a mixture of irritants.