Do chronic workplace irritant exposures cause asthma?

Abstract

Evidence of a causal effect of chronic workplace irritant exposure in new-onset asthma remains limited, mainly because of a lack of longitudinal studies and the difficulty to evaluate irritant exposures. However, recent epidemiological studies strengthen the evidence of an effect of chronic exposure to irritants in work-related asthma. The underlying mechanism remains unknown but may be related to oxidative stress, neurogenic inflammation and dual irritant and adjuvant effects. However, disentangling chronic irritant effects from either acute irritant-induced asthma or immunological low molecular weight agent-induced asthma is difficult for some agents. Further research is needed to improve assessment of irritant exposures and identify biomarkers.

Occupational exposure to disinfectants and asthma control in US nurses

“…[17] Moreover, we evaluated asthma control using a standardized and validated definition (ACT) [1, 22], integrating the main domains of asthma control (symptoms, use of rescue therapy, sleep interference, activity limitations). Many studies on work-related asthma have focused on distinguishing risk factors for occupational asthma (i.e., new-onset asthma caused by occupational exposure) and work-exacerbated asthma (worsening of a pre-existing asthma) [23, 24]. In the current study, the association between use of disinfectants and poor asthma control was similar among nurses with childhood-onset (i.e., pre-existing) and adult-onset (i.e., potentially caused by occupational exposures) asthma.…”

“…Some products (e.g. enzyme-based products) have sensitizing potential, but most agents are assumed to act as respiratory irritants [11], and may cause injury of the airway epithelium, oxidative stress and long-lasting neurogenic inflammation [23, 24, 29]. Regardless of the exact mechanisms, our results support the need to consider occupation and potential exposure to disinfectants in clinical practice to improve management of patients with asthma [6, 30].…”

Update of an occupational asthma-specific job exposure matrix to assess exposure to 30 specific agents

“…Agriculture workers are exposed to many agents associated with asthma 3. These agents are often heterogeneous in terms of mechanisms, as they may include both allergens, such as animal proteins, and irritants, such as pesticides and cleaning products.…”

“…The proportion of asthma in adults attributable to occupational exposures is estimated to be around 15% 2. The burden of work-related asthma is underestimated partly due to limited knowledge about occupational exposure to well-established asthmagens 3. In addition, new asthmagens are constantly being reported 4.…”

Opportunities and obstacles in translating evidence to policy in occupational asthma

“…High-level accidental exposures to irritant gases can induce OA without latency, commonly called reactive airways dysfunction syndrome. In addition, chronic exposure to lower levels of irritants may result in asthma as well, although this remains under investigation [81]. With other disinfecting ingredients, sensitizing mechanisms are suspected but often only partially understood.…”