Historical legacies of river pollution reconstructed from fish scales

Many rivers have been impacted by heavy metal pollution in the past but the long-term legacies on biodiversity are difficult to estimate. The River Ulla (NW Spain) was impacted by tailings from a copper mine during the 1970-1980s but absence of baseline values and lack of subsequent monitoring have prevented a full impact assessment. We used archived fish scales of Atlantic salmon to reconstruct levels of historical copper pollution and its effects on salmon fitness. Copper bioaccumulation significantly increased over baseline values during the operation of the mine, reaching sublethal levels for salmon survival. Juvenile growth and relative population abundance decreased during mining, but no such effects were observed in a neighbouring river unaffected by mining. Our results indicate that historical copper exposure has probably compromised the fitness of this Atlantic salmon population to the present day, and that fish scales are suitable biomarkers of past river pollution

Occupational asthma caused by an epoxy amine hardener

We describe a 43-year-old epoxy floor layer who developed work-related asthma while exposed to an epoxy hardener based on isophorone diamine (IPDA). Challenge exposures to the curing of the epoxy resin system and subsequently to the polyfunctional amine hardener containing IPDA both elicited delayed asthmatic reactions. This report further indicates that exposure to epoxy hardeners containing polyfunctional amines should be considered as a potential cause of occupational asthma. Appropriate work hygiene measures should be implemented to minimize airborne exposure to these volatile compounds

Sputum Inflammatory Patterns are Associated with Distinct Clinical Characteristics in Subjects with Occupational Asthma Independently from the Causal Agent.

Clinical heterogeneity in sensitizer-induced occupational asthma (OA) and its relationship to airway inflammatory profiles remain poorly elucidated. To further characterize the interactions between induced sputum inflammatory patterns, asthma-related outcomes and the high- or low-molecular-weight category of causal agents in a large cohort of subjects with OA. This multicenter, retrospective, cross-sectional study was conducted among 296 subjects with OA ascertained by a positive specific inhalation challenge who completed induced sputum assessment before and 24 hours after challenge exposure. Multivariate logistic regression analysis revealed that sputum eosinophilia ≥3% was significantly associated with a high dose of inhaled corticosteroid (odds ratio [95% confidence interval], 1.31 [1.11-1.55] for each 250-µg increment in daily dose), short-acting b2-agonist use less than once a day (3.54 [1.82-7.00]), and the level of baseline nonspecific bronchial hyperresponsiveness (mild: 2.48 [1.21-5.08]); moderate/severe: 3.40 [1.44-8.29]). Sputum neutrophilia ≥76% was associated with age (1.06 [1.01-1.11]), male gender (3.34 [1.29-9.99]), absence of corticosteroid use (5.47 [2.09-15.16]), short-acting b2-agonist use once or more a day (4.09 [1.71-10.01]), ≥2 severe exacerbations during the last 12 months at work (4.22 [1.14-14.99]), and isolated early reactions during the SIC (4.45 [1.85-11.59]). The findings indicate that sputum inflammatory patterns in subjects with OA are associated with distinct phenotypic characteristics and further highlight the differential effects of neutrophils and eosinophils on asthma-related outcomes. These associations between inflammatory patterns and clinical characteristics share broad similarities with what has been reported in nonoccupational asthma and are not related to the type of causal agent

Phenotyping occupational asthma caused by acrylates in a multicentre cohort study.

BACKGROUND While acrylates are well-known skin sensitisers, they are not classified as respiratory sensitisers although several cases of acrylate-induced occupational asthma (OA) have been reported. OBJECTIVES The aim of this study was to evaluate the characteristics of acrylate-induced OA in a large series of cases and compare those with OA induced by other low-molecular-weight (LMW) agents. METHODS Jobs and exposures, clinical and functional characteristics, and markers of airway inflammation were analysed in an international, multicentre, retrospective cohort of subjects with OA ascertained by a positive inhalation challenge to acrylates (n= 55) or other LMW agents (n=418) including isocyanates (n=125). RESULTS Acrylate-containing glues were the most prevalent products and industrial manufacturing, dental work and beauty care were typical occupations causing OA. Work related rhinitis was more common in acrylate than isocyanate-induced asthma (p<0.001). The increase in post-challenge fractional exhaled nitric oxide (FeNO) was significantly greater in acrylate-induced OA (26.0, 8.2-38.0 ppb) than in OA induced by other LMW agents (3.0, -1.0-10.0 ppb, p<0.001) or isocyanates (5.0, 2.0-16.0 ppb, p=0.010). Multivariable models confirmed that OA induced by acrylates was significantly and independently associated with a post-challenge increase in FeNO (≥17.5 ppb). CONCLUSIONS Acrylate-induced OA shows specific characteristics, concomitant work-related rhinitis and exposure-related increases in FeNO, suggesting that acrylates may induce asthma through different immunological mechanisms than other LMW agents. Our findings reinforce the need for a re-evaluation of the hazard classification of acrylates, and further investigation of the pathophysiological mechanisms underlying their respiratory sensitizing potential

Characterization of Occupational Eosinophilic Bronchitis in a Multicenter Cohort of Subjects with Work-Related Asthma Symptoms

Background: Occupational eosinophilic bronchitis (OEB) has been described only as anecdotal case reports. Objective: We investigated the clinical and inflammatory characteristics of subjects with OEB identified in a cohort of subjects who completed a specific inhalation challenge (SIC) with occupational agents. Methods: In this retrospective multicenter study, OEB was defined by (1) a fall in FEV1 less than 15% during the SIC and the absence of nonspecific bronchial hyperresponsiveness both before and after the SIC and (2) a postchallenge increase of 3% or more in sputum eosinophils. The subjects who fulfilled these criteria were compared with 226 subjects with a negative SIC and 30 subjects with a positive SIC who failed to show baseline nonspecific bronchial hyperresponsiveness. Results: An isolated increase in postchallenge sputum eosinophils was documented in 33 of 259 subjects (13%) with a negative SIC. These subjects reported significantly more often an isolated cough at work compared with the negative and positive SIC controls. When compared with positive SIC controls, the subjects with OEB experienced less frequently work-related wheezing and reported a shorter duration of symptoms at work. The sensitivity of the post-SIC increase in fractional exhaled nitric oxide in identifying OEB among subjects with a negative SIC was low, ranging from 43% to 24% using cutoff values of 8 ppb to 17.5 ppb, whereas the specificity was high (90%-97%). Conclusions: This study highlights the relevance of induced sputum analysis in the investigation of work-related asthma symptoms to identify isolated increases in sputum eosinophils that are consistent with a diagnosis of OEB

Individual movements, home ranges and habitat use by native rheophilic cyprinids and non-native catfish in a large regulated river

The mobility patterns of two native species, barbel, Barbus barbus (L.) and chub, Squalius cephalus (L.), and of one non-native fish species, the catfish Silurus glanis (L.), were assessed on a 35.5-km reach of the Upper Rhône River, a strong flowing river with notable thermal regime alterations. An active acoustic tracking technique adapted to large rivers allowed (1) the identification of longitudinal home ranges, movements and preferred habitat at large scale, and (2) the analysis of the influence of discharge and water temperature on the movement patterns of the fish. The active fish-tracking system recorded 1,572 fish localisations over 7 months on a weekly basis for 80% of the tagged fish (37 barbel, 23 chub and 13 catfish). Compared with the catfish, barbel and chub showed wider longitudinal home ranges, more movements >1 km and higher interindividual variability. The catfish preferred artificially heated habitats with less morphological diversity. The three species were more often localised in river sections with high density of woody debris. The results suggest that habitat degradation is more damaging for cyprinids in large modified rivers, while the catfish seemed less, impacted