Explore the vast range of titles available.

Biological risks potentially affect workers in multiple occupational sectors through their exposure to pathogenic agents. These risks must be carefully assessed to prevent adverse health effects. This article identifies and critically analyzes approaches that manage the qualitative evaluation of biological risk (EvBR) as part of occupational health and safety prevention, for which no standard method yet exists. Bibliographic and computing references were searched to identify qualitative EvBR approaches, which were then analyzed based on defined criteria, such as the risks studied and the type of assessment. Approaches proposing the most representative types of assessment were analyzed. EvBR approaches in an occupational setting were identified in 32 sources. “Workstation analysis” combined with “assessment by risk level” were the most common approaches. The predominant risk descriptors (RDs) were defined in a characterized and quantifiable way, and a variety of hazard levels and exposure indices were created. Overall, the risk was determined by summing or multiplying the hazard level and exposure indicators. The results confirmed that no methodological consensus currently exists regarding the EvBR and no approach has yet been described that integrates all the parameters to allow for a full assessment of biological risk. Based on the detailed analysis of the existing data, the present paper proposes a general approach.

A study was carried out in a waste sorting plant (WSP) located in France, treating dry recyclable household waste (DRHW) as well as dry recyclable commercial and industrial waste (DRCIW). Stationary and personal inhalable samples were collected in the WSP in order to investigate bioaerosols (sampling on a filter; 2 L/min and 10 L/min) and airborne dust (CIP; 10 L/min). The aim of the study was to assess the extent to which the measurement of concentration, species composition, and particle size distribution contributes to a better assessment of the biological risks associated with exposure. The results confirmed that waste and waste sorting activities are sources of airborne fungi. Indeed, ambient concentrations ranged from 7.3 × 103 to 8.5 × 105 colony-forming units (CFU)/m3 for culturable fungi and up to 4 mg/m3 for dust. Personal exposure to inhalable dust was found up to 3 mg/m3 for dust and ranged from 8.6 × 103 to 1.5 × 106 CFU/m3 for fungi. Airborne fungal communities were found to be dominated by the Penicillium genera in both bioaerosols and settled dust samples, followed by the Aspergillus, Cladosporium, Wallemia, Mucor, and Rhizopus genera. Fungi were carried by particles of aerodynamic diameters, mainly between around 2.0 and 10.0 µm. The findings dealing with size distribution and biodiversity of bioaerosols suggest that employees are exposed to complex bioaerosols during their work and help to make a finer diagnosis of the risks involved, which is often difficult in the absence of any occupational exposure limit (OEL) value for bioaerosols in general.

The measurement of airborne endotoxins is often necessary because of the inhalation of these lipopolysaccharides from most Gram-negative bacteria is known to provoke harmful effects on worker’s health including acute respiratory symptoms. Sampling on filters is one of the most widely used methods for measuring endotoxins in the air, and the present article confirms that there is a wide variety of filters used for the measurement. This article provides an expert opinion based on a mini review on the influence of the nature of the filter used on the measurement results. First, the analysis of published studies shows that the measurement of endotoxins, either at the workplace or in laboratory conditions, is carried out with different measurement protocols from one study to another, at least with regard to the filter used. Secondly, this is questioning since the equivalence of protocols in terms of measurement performance has not been fully investigated. In particular, the review of studies that have investigated the effect of the filter on the measurement of airborne endotoxins is quite contradictory, and no recent published study has provided any tangible evidence. This leads to the conclusion that the current recommendations regarding the type of filters to be used for endotoxin measurements are based on insufficient data. Thus, additional experimental studies are required. Thirdly, a detailed and argued survey of the mechanisms involved in the measurement has been carried in order to facilitate the construction of further studies. This allowed identifying the factors, including either physical or chemical properties of the filter, to be taken into account in studies on the effect of the filter on the measurement of endotoxins in the air and specifying the issues that have not yet been investigated. Finally, the results of these studies should allow a more objective orientation towards a given type of filter and could complement the recommendations of the EN14031 standard.

Rationale and objectivesCompost workers have more airway irritation symptoms and increased inflammation markers than non-exposed workers. We studied which activities and processed wastes are involved.Methods90 compost workers were followed-up for 18 months with a medical examination every 6 months. At each visit, two questionnaires on the preceding six-months, regarding the tasks of a typical work-week and respiratory health and irritation symptoms, were administered. Fractional exhaled nitric oxide (NOe) measures, spirometry and a methacholine challenge test (MCT) were performed. Skin prick-tests for common aeroallergens were performed on the first visit, and immunoglobulin (Ig) E and G specific to airborne microorganisms commonly observed in composting plants were quantified on two visits. ResultsSixty-one subjects (68%) worked in 20 green waste (GW) plants and 29 (32%) in 15 sewage sludge (SS) plants. Thirteen workers (14%) were drivers or mechanics considered as having low exposure. Thirty-seven workers were atopic (42%) and 12 (13%) had ever-asthma. Workers in plants processing the highest quantities of waste had more upper (OR = 7.5, IC95%=[1.3; 42.7]) and lower (OR = 1.05, IC95%=[1.0; 1.1]) airway irritation symptoms and digestive symptoms (OR = 1.23, IC95%=[1.0; 1.5]), and more frequently altered FVC (OR = 1.3, IC95%=[1,1; 1,5]) and FEV1 (OR = 1.2, IC95%=[1.0; 1.4]). Mixing materials (OR = 1.04, IC95%=[1.0; 1.1]) and handling compost (OR = 1.13, IC95%=[1.0; 1; 2]) were tasks associated with more asthma-like symptoms. Cleaning activities were associated with a higher MCT dose-response slope ( beta = -0.010, IC95%=[-0.019; -0.001]). Workers in GW plants had a higher risk of having an increased NOe than workers in SS plants (OR = 45.8, IC95%=[2.6; 808.2]). Less exposed workers had a lower level of IgE specific to actinomycetes (exp( beta )=1.17, IC95%=[1.04; 1.32]). ConclusionThis is the first time the characteristics of the plants, tasks performed and types of waste processed have been linked to markers of airway inflammation and symptoms in compost workers.

Biological degreasing system is a new technology based on the degradation capabilities of microorganisms to remove oil, grease, or lubricants from metal parts. No data is available about the potential biological health hazards in such system. Thus, a health risk assessment linked to the bacterial populations present in this new degreasing technology is, therefore, necessary for workers. We performed both cultural and molecular approaches in several biological degreasing systems for various industrial contexts to investigate the composition and dynamics of bacterial populations. These biological degreasing systems did not work with the original bacterial populations. Indeed, they were colonized by a defined and restricted group of bacteria. This group replaced the indigenous bacterial populations known for degrading complex substrates. Klebsiella pneumoniae, Klebsiella oxytoca, Pseudomonas aeruginosa, and Pantoea agglomérons were important members of the microflora found in most of the biological degreasing systems. These bacteria might represent a potential health hazard for workers.

The aim of this work was to study how the location of a carbon source and of bacterial cells in soil can enhance the growth of a bacterial inoculum. Studies were performed using irradiated soil and two pairs of strains of Bradyrhizobium japonicum and Pseudomonas fluorescens. For each species, an antibiotic-resistant mutant was used as inoculant and introduced into a sterile soil pre-colonised with its parent strain. The inocula and a glycerol amendment were introduced together or separately into soil using porous microgranules or by spraying a suspension onto the bulk soil. Competition was assessed by plate counts of both inoculant and established populations. Both B. japonicum and P. fluorescens parent strains established at a high density level (10 9 cells g −1 of dry soil) in the sterile soil. The effects of the amendment on the inoculant strain in soil were strongly dependent on the way the cells and the substrate were introduced into the soil. Joint introduction of cells and substrate into soil improved the growth of the inoculant strain, but the effect of the amendment was also shown to be dependent on the inoculant carrier. Location of glycerol and the inoculant strain in microgranules gave a competitive advantage to the inoculated bacterium for a part of the amendment. We suggest that diffusion of glycerol from microgranules to the soil limits the competitive advantage of such location effects.

The aim of this work was to study how the location of a carbon source and of bacterial cells in soil can enhance the growth of a bacterial inoculum. Studies were performed using irradiated soil and two pairs of strains of Bradyrhizobium japonicum and Pseudomonas fluorescens. For each species, an antibiotic-resistant mutant was used as inoculant and introduced into a sterile soil pre-colonised with its parent strain. The inocula and a glycerol amendment were introduced together or separately into soil using porous microgranules or by spraying a suspension onto the bulk soil. Competition was assessed by plate counts of both inoculant and established populations. Both B. japonicum and P. fluorescens parent strains established at a high density level (10(9) cells g(-1) of dry soil) in the sterile soil. The effects of the amendment on the inoculant strain in soil were strongly dependent on the way the cells and the substrate were introduced into the soil. Joint introduction of cells and substrate into soil improved the growth of the inoculant strain, but the effect of the amendment was also shown to be dependent on the inoculant carrier. Location of glycerol and the inoculant strain in microgranules gave a competitive advantage to the inoculated bacterium for a part of the amendment. We suggest that diffusion of glycerol from microgranules to the soil limits the competitive advantage of such location effects.