Bioaerosol exposure assessment in the workplace: the past, present and recent advances

Abstract

Louis Pasteur described the first measurements of airborne microorganisms in 1861. A century later, the inhalation of spores from thermophilic microorganisms was shown to induce attacks of farmers' lung in patients with this disease, while endotoxins originating from Gram-negative bacteria were identified as causal agents for byssinosis in cotton workers. Further epidemiological and toxicological studies have demonstrated inflammatory, respiratory, and pathogenic effects following exposure to bioaerosols. Exposure assessment is often confounded by the diversity of bioaerosol agents in the environment. Microorganisms represent a highly diverse group that may vary in toxicity. Fungi and bacteria are mainly quantified as broad groups using a variety of viable and nonviable assessment methods. Endotoxins and β(1 → 3)-glucans are mainly measured by their activity in the Limulus amebocyte lysate assay, enzymes by immuno-chemical methods and mycotoxins by liquid chromatography-mass spectrometry. Few health-based occupational exposure limits (OELs) are available for risk assessment. spores recently proposed a lowest observed effect level of 100 000 spores m −3 for non-pathogenic and non-mycotoxin producing species based on inflammatory respiratory effects. Recent developments in bioaerosol assessment were presented at the Organic Dust Tromsł Symposium including molecular biological methods for infectious agents and organisms that are difficult to cultivate; studies of submicronic and hyphal fragments from fungi; the effect of biodiversity of microorganisms in asthma studies; and new/improved measurement methods for fungal antigens, enzymes and allergens. Although exposure assessment of bioaerosol agents is complex and limited by the availability of methods and criteria, the field is rapidly evolving. HHS Public Access

Current Status of the Red King Crab (Paralithodes camtchaticus) and Snow Crab (Chionoecetes opilio) Industries in Norway

“…Norway lacks occupational exposure limits and standardized, reproducible methods for collecting and analyzing such samples (Douwes et al, 1995;Eduard et al, 2012). Since there are no known safe levels of exposure, the main measures taken by processing factories are to reduce exposure by installing shields on work stations and applying more automatic processing operations.…”

Occupational Exposure to Bioaerosols in Norwegian Crab Processing Plants

“…Attempts to compare and evaluate bioaerosol exposure levels are hampered by the lack of occupational exposure limits and standardised, reproducible methods for collecting and analysing the samples (Eduard et al 2012;Douwes et al 1995). The levels of exposure to total protein and allergens such as tropomyosin have been measured to some extent in other studies in the seafood industry.…”

“…Adverse health effects from bioaerosol exposure (Eduard et al 2012;Shiryaeva et al 2013;Watanabe et al 2016;Gautrin et al 2010;Jeebhay et al 2008) such as immunological sensitisation, respiratory symptoms, bronchial hyper-responsiveness and occupational asthma have been found in exposed seafood workers. Sensitisation is documented in workers processing fish, mussels, prawns and crabs.…”

Bioaerosol deposition on an air-conditioning cooling coil

“…In addition to microbial DNA, 323 environmental DNA-containing bioaerosols can include pollen, viral DNA, vegetation debris 324 and insect debris (Eduard et al, 2012). 325…”