Jeremy Beach

Diagnosis and Management of Work-Related Asthma: American College of Chest Physicians Consensus Statement

BACKGROUND A previous American College of Chest Physicians Consensus Statement on asthma in the workplace was published in 1995. The current Consensus Statement updates the previous one based on additional research that has been published since then, including findings relevant to preventive measures and work-exacerbated asthma (WEA). METHODS A panel of experts, including allergists, pulmonologists, and occupational medicine physicians, was convened to develop this Consensus Document on the diagnosis and management of work-related asthma (WRA), based in part on a systematic review, that was performed by the University of Alberta/Capital Health Evidence-Based Practice and was supplemented by additional published studies to 2007. RESULTS The Consensus Document defined WRA to include occupational asthma (ie, asthma induced by sensitizer or irritant work exposures) and WEA (ie, preexisting or concurrent asthma worsened by work factors). The Consensus Document focuses on the diagnosis and management of WRA (including diagnostic tests, and work and compensation issues), as well as preventive measures. WRA should be considered in all individuals with new-onset or worsening asthma, and a careful occupational history should be obtained. Diagnostic tests such as serial peak flow recordings, methacholine challenge tests, immunologic tests, and specific inhalation challenge tests (if available), can increase diagnostic certainty. Since the prognosis is better with early diagnosis and appropriate intervention, effective preventive measures for other workers with exposure should be addressed. CONCLUSIONS The substantial prevalence of WRA supports consideration of the diagnosis in all who present with new-onset or worsening asthma, followed by appropriate investigations and intervention including consideration of other exposed workers.

Occupational Pesticide Exposures and Respiratory Health

Pesticides have been widely used to control pest and pest-related diseases in agriculture, fishery, forestry and the food industry. In this review, we identify a number of respiratory symptoms and diseases that have been associated with occupational pesticide exposures. Impaired lung function has also been observed among people occupationally exposed to pesticides. There was strong evidence for an association between occupational pesticide exposure and asthma, especially in agricultural occupations. In addition, we found suggestive evidence for a link between occupational pesticide exposure and chronic bronchitis or COPD. There was inconclusive evidence for the association between occupational pesticide exposure and lung cancer. Better control of pesticide uses and enforcement of safety behaviors, such as using personal protection equipment (PPE) in the workplace, are critical for reducing the risk of developing pesticide-related symptoms and diseases. Educational training programs focusing on basic safety precautions and proper uses of personal protection equipment (PPE) are possible interventions that could be used to control the respiratory diseases associated with pesticide exposure in occupational setting.

Endotoxin as a determinant of asthma and wheeze among rural dwelling children and adolescents: A case–control study

BackgroundThe association between endotoxin exposure and asthma is complex and has been associated with rural living. We examined the relationship between domestic endotoxin and asthma or wheeze among rural school-aged children (6–18 years) and assessed the interaction between endotoxin and other characteristics with these outcomes.MethodsBetween 2005 and 2007 we conducted a case–control study of children 6–18 years in the rural region of Humboldt, Canada. Cases (n = 102) reported doctor-diagnosed asthma or wheeze in the past year. Controls (n = 208) were randomly selected from children without asthma or wheeze. Data were collected to ascertain symptoms, asthma history and indoor environmental exposures (questionnaire), endotoxin (dust collection from the play area floor and child’s mattress), and tobacco smoke exposure (saliva collection). Statistical testing was completed using multiple logistic regression to account for potential confounders and to assess interaction between risk factors. A stratified analysis was also completed to examine the effect of personal history of allergy.ResultsAmong children aged 6–12 years, mattress endotoxin concentration (EU/mg) and load (EU/m2) were inversely associated with being a case [odds ratio (OR) = 0.44, 95% confidence interval (CI) = 0.20-0.98; and OR = 0.38, 95% CI = 0.20-0.75, respectively]. These associations were not observed in older children or with play area endotoxin.ConclusionsOur results suggest that endotoxin exposure might be protective for asthma or wheeze. The protective effect is found in younger school-aged, non-allergic children. These results may help explain the inconsistencies in previous studies and suggest that the protective effects of endotoxin in the prevention of atopy and asthma or wheeze are most effective earlier in life.

Relationship Between Indoor Environment and Asthma and Wheeze Severity Among Rural Children and Adolescents

ABSTRACT Few studies have examined the associations between environmental characteristics and asthma severity among children in a rural setting. The authors studied these associations using a number of asthma severity indicators. They conducted a case-control study of 6- to 18-year-old children and adolescents in Humboldt, Saskatchewan, and the surrounding area. Only cases representing subjects reporting wheeze in the past 12 months or doctor-diagnosed asthma were used for the present analysis (n = 98). Data were collected by questionnaire, while vacuumed dust (mattress and play area floor) was used for the quantification of endotoxin exposure, and saliva was used for the measurement of cotinine to assess tobacco smoke exposure. Severity indicators included wheeze frequency, breathing medication use, sleep disruption from wheeze, and school absenteeism, all in the past 12 months. A majority of cases were male (62.3%). Wheezing 1 to 3 times was reported by 40.8% of cases, whereas 17.3% wheezed 4 or more times in the past 12 months. Short-acting beta agonist medications or inhaled corticosteroids alone were used by 24.5% of the cases, whereas 33.7% of the cases used multiple or additional breathing medications. Sleep disruption was reported by 28.6% of the cases, whereas 12.2% reported at least one school absence. High tobacco smoke exposure was associated with increased wheeze frequency. There was an inverse association between play area endotoxin concentration and school absenteeism, with some indication of interaction with tobacco smoke exposure. House-cleaning behaviors and changes in health behaviors resulting from the childs respiratory condition were different between those with and without report of sleep disruption due to wheeze. Several environmental variables were associated with severity indicators. However, the associations were not consistent between indicators, suggesting that other factors or changes in behavior resulting from the disease should be considered when assessing these associations.

Workplace interventions for treatment of occupational asthma: a Cochrane systematic review

Occupational asthma is the most frequently reported work-related respiratory disease in many countries. It is defined as asthma that is caused by a specific workplace exposure to certain substances and not to factors outside the workplace. In a recent review, the population attributable risk for adult onset asthma being caused by occupational exposures was 17.6%. Occupational asthma can lead to decreased quality of life, sickness absence and increased costs for the patient, the employer and society. Common causes of occupational asthma include exposure to high molecular weight (HMW) agents such as wheat, latex and animal proteins, or to low molecular weight (LMW) agents such as di-isocyanates, acid anhydrides, platinum salts and plicatic acid. There are no systematic reviews of controlled studies of workplace interventions for occupational asthma. Therefore, we conducted a Cochrane systematic review to evaluate the effectiveness of workplace interventions on the outcome of occupational asthma.1 We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, NIOSHTIC-2, CISDOC and HSELINE up to February 2011. We intended to include randomised controlled trials, controlled before and …

Associations between dietary factors and urinary concentrations of organophosphate and pyrethroid metabolites in a Canadian general population

OBJECTIVES Few studies to date have characterized the relationships between diet and urinary concentrations of pesticides. In the current study, associations between dietary factors and urinary concentrations of organophosphate and pyrethroid metabolites were examined in a Canadian general population using data from the Canadian Health Measures Survey (CHMS). METHODS In the CHMS, urinary concentrations of dialkylphosphate (DAP) and pyrethroid metabolites were measured in 5604 participants aged 6-79 years. Associations between dietary factors and total concentrations of DAP (ΣDAP) and pyrethroid metabolites (ΣPYR) were examined. RESULTS Over 90% of participants had at least one type of DAP and 99.8% had pyrethroid metabolites detectable in urine samples. After adjusting for age, sex, race/ethnicity, immigrant status and body mass index, ΣDAP among participants with high (3rd tertile) fruit consumption was 1.43 (95% CI: 1.26-1.61) times the concentration among those with low (1st tertile) consumption. ΣDAP was also positively associated with vegetable consumption, for those with high consumption ΣDAP being 1.33 times (95% CI: 1.16-1.52) the concentration for those with low consumption. ΣPYR among participants with high vegetable consumption was 1.42 (95% CI: 1.23-1.66) times the concentration among those with low vegetable consumption. ΣPYR was also positively associated with pulses/nuts consumption (p-values<0.01) and household use of chemicals to control head lice or pet flea (p=0.002). CONCLUSIONS Positive associations between dietary factors and urinary concentrations of organophosphate and pyrethroid metabolites suggest greater regulation of pesticide use on food products may help to reduce pesticide exposures and associated health risks among the general population.

Fragrance materials in asthma: a pilot study using a surrogate aerosol product

Abstract Objective: Many household products contain fragrances. Little is known about exposure to fragrances on human health, particularly within the airways. This study aimed to evaluate how common household fragrance products (i.e. air fresheners, cleaning products) affect people with asthma, who frequently report sensitivity to these products. Many of these products have volatile organic compounds or semi-volatile organic compounds. This study evaluated nine fragrance materials in an aerosol formulation to assess effects on airway physiology, airway inflammation and symptom perception in normal controls and those with asthma. Methods: The effects of fragrances were evaluated in people without asthma, people with mild asthma and people with moderate asthma in a four-way crossover placebo-controlled study. Subjects were exposed twice to a fragranced aerosol and twice to a placebo aerosol (15 and 30 min each). Subjects completed a questionnaire for 29 symptoms during and up to 3 h after each exposure scenario. Spirometry was performed prior to and 3 h post-exposure; sputum induction was conducted 3 h post-exposure. Results: Nasal symptoms showed the greatest frequency of response in all three subject groups, and moderate asthmatics reported the greatest symptom severity and symptom types. No significant differences were noted in physiology or cellular inflammation. Conclusion: A trend for increased symptoms was noted in moderate asthmatics, suggesting that asthma severity may play a factor in fragrance sensitivity.

Prevalence of and Risk Factors for Asthma in Off-Reserve Aboriginal Children and Adults in Canada

Only a few studies have investigated asthma morbidity in Canadian Aboriginal children. In the present study, data from the 2006 Aboriginal Peoples Survey were used to determine the prevalence and risk factors for asthma in Canadian Aboriginal children six to 14 years of age and adults 15 to 64 years of age living off reserve. The prevalence of asthma was 14.3% in children and 14.0% in adults. Children and adults with Inuit ancestry had a significantly lower prevalence of asthma than those with North American Indian and Métis ancestries. Factors significantly associated with ever asthma in children included male sex, allergy, low birth weight, obesity, poor dwelling conditions and urban residence. In adults, factors associated with ever asthma varied among Aboriginal groups; however, age group, sex and urban residence were associated with ever asthma in all four Aboriginal groups. The prevalence of asthma was lower in Aboriginal children and higher in Aboriginal adults compared with that reported for the Canadian population. Variation in the prevalence of and risk factors for asthma among Aboriginal ancestry groups may be related to genetic and environmental factors that require further investigation.

Do clinicians working within the same context make consistent return-to-work recommendations?

Introduction Healthcare providers play important roles in the process of making return-to-work (RTW) recommendations, which have important consequences for injured workers and their employers. We studied the inter-rater reliability of RTW determinations between clinicians in a specific workers’ compensation setting. Methods Three case scenarios were given to clinicians working at one rehabilitation facility to examine consistency between clinicians in RTW recommendations. Additionally, we examined what information clinicians relied on to make decisions. Analysis included percentage agreement and other descriptive statistics. Results Thirty-six clinicians (13 physiotherapists, 10 occupational therapists, 8 exercise therapists, and 5 physicians) responded to the questionnaire. Subjects showed a high percentage agreement regarding RTW readiness on fracture and dislocation scenarios (97.2 and 94.4%, respectively), while agreement on a back pain scenario was modest (55.6%). In all cases, more than 50% of clinicians relied on biomedical information, such as physical examination. Conclusions Clinicians demonstrated a high level of agreement (>94%) when making RTW recommendations for injuries with clear pathology. However, a lower level of agreement (56%) was observed for back pain where the etiology of pain and disability is often more complex. Clinicians most commonly recommended RTW with restrictions, underlining the importance of workplace accommodations and modified duties in facilitating resumption of work.

Relationship of endotoxin and tobacco smoke exposure to wheeze and diurnal peak expiratory flow variability in children and adolescents

Background and objective:  The relationship between endotoxin exposure and asthma severity (wheeze and airways obstruction) is not well described. The effects of endotoxin and tobacco smoke exposure on self‐reported wheeze and diurnal PEF variability (DV‐PEF) were examined in children aged 6–18 years with asthma or wheeze.