Chitinase digestion for the analysis of microplastics in chitinaceous organisms using the terrestrial isopod Oniscus asellus L. as a model organism

Chitinaceous organisms have been found to ingest microplastic; however, a standardised, validated, and time- and cost-efficient method for dissolving these organisms without affecting microplastic particles is still required. This study tested four protocols for dissolving organisms with a chitin exoskeleton: 1) potassium hydroxide (KOH) + chitinase, 2) Creon® + chitinase, 3) hydrogen peroxide (H2O2) + chitinase, and, 4) Nitric Acid (HNO3) + hydrogen peroxide (H2O2). The effects on microplastics composed of eight different polymers were also tested. The use of H2O2 followed by chitinase was found to be a highly efficient method. The three other protocols either did not digest the chitin sufficiently or negatively affected the tested polymers. A recovery test using microplastic fibres, beads and tyre particles revealed high recovery rates of 0.85, 0.89 and 1 respectively. This further supported the applicability of the H2O2 and chitinase (protocol 3) for dissolving chitinaceous organisms. Thus, we recommend that future investigations of microplastic (0.05 μm–5000 μm) in chitinaceous organisms (0.3 cm–5 cm) utilise the here presented methodology. This represents an important component of the ongoing validation and harmonization of methodological approaches that are urgently needed for the advancement of microplastic assessments globally.publishedVersio

Sequence analysis of sickness absence and disability pension in the year before and the three years following a bicycle crash; a nationwide longitudinal cohort study of 6353 injured individuals

Background:Bicyclists are the road user group with the highest number of severe injuries in the EU, yet little is known about sickness absence (SA) and disability pension (DP) following such injuries.\ua0Aims: To explore long-term patterns of SA and DP among injured bicyclists, and to identify characteristics associated with the specific patterns. Methods: A longitudinal register-based study was conducted, including all 6353 individuals aged 18–59 years and living in Sweden in 2009, who in 2010 had incident in-patient or specialized out-patient healthcare after a bicycle crash. Information about sociodemographic factors, the injury, SA (SA spells > 14 days), and DP was obtained from nationwide registers. Weekly SA/DP states over 1 year before through 3 years after the crash date were used in sequence and cluster analyses. Multinomial logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for factors associated with each identified sequence cluster. Results: Seven clusters were identified: “No SA or DP” (58.2% of the cohort), “Low SA or DP” (7.4%), “Immediate SA” (20.3%), “Episodic SA” (5.9%), “Long-term SA” (1.7%), “Ongoing part-time DP” (1.7%), and “Ongoing full-time DP” (4.8%). Compared to the cluster “No SA or DP”, all other clusters had higher ORs for women, and higher age. All clusters but “Low SA and DP” had higher ORs for inpatient healthcare. The cluster “Immediate SA” had a higher OR for: fractures (OR 4.3; CI 3.5–5.2), dislocation (2.8; 2.0–3.9), sprains and strains (2.0; 1.5–2.7), and internal injuries (3.0; 1.3–6.7) compared with external injuries. The cluster “Episodic SA” had higher ORs for: traumatic brain injury, not concussion (4.2; 1.1–16.1), spine and back (4.5; 2.2–9.5), torso (2.5; 1.4–4.3), upper extremities (2.9; 1.9–4.5), and lower extremities (3.5; 2.2–5.5) compared with injuries to the head, face, and neck (not traumatic brain injuries). The cluster “Long-term SA” had higher ORs for collisions with motor vehicles (1.9;1.1–3.2) and traumatic brain injury, not concussion (18.4;2.2–155.2). Conclusion: Sequence analysis enabled exploration of the large heterogeneity of SA and DP following a bicycle crash. More knowledge is needed on how to prevent bicycle crashes and especially those crashes/injuries leading to long-term consequences

Sickness Absence Due to Otoaudiological Diagnoses and Risk of Disability Pension: A Nationwide Swedish Prospective Cohort Study

Background: Hearing difficulties are a large public health problem. Knowledge is scarce regarding risk of disability pension among people who have been sickness absent due to these difficulties. Methods: A cohort including all 4,687,756 individuals living in Sweden in 2005, aged 20–64, and not on disability or old-age pension, was followed through 2009. Incidence rate ratios (RR) of disability pension with 95 % confidence intervals (CI) were estimated using Cox proportional hazard models. Results: In multivariable models, individuals who had a sick-leave spell due to otoaudiological diagnoses in 2005 had a 1.52fold (95 % CI: 1.43–1.62) increased risk of being granted a disability pension compared to individuals on sick leave due to other diagnoses. Hearing and tinnitus sick-leave diagnoses were associated with risk of disability pension: RR 3.38, 95 % CI: 3.04–3.75, and 3.30, 95 % CI: 2.95–3.68, respectively. No association was observed between sick leave due to vertigo diagnoses and disability pension whereas otological diagnoses and no sick leave were inversely associated with risk of disability pension compared to non-otoaudiological sick-leave diagnoses. Sick leave due to otoaudiological diagnoses was positively associated with risk of disability pension due to otoaudiological diagnoses and sick leave due to a tinnitus diagnosis was also associated with risk of disability pension due to mental diagnoses. The risk of disability pension among individuals with hearing or tinnitus sick-leave diagnoses was highest in the age group 35–44. Moreover, men had a slightl

Diagnosis-specific sickness absence among injured working-aged pedestrians: a sequence analysis

BACKGROUND: The knowledge about the long-term consequences in terms of sickness absence (SA) among pedestrians injured in a traffic-related accident, including falls, is scarce. Therefore, the aim was to explore diagnosis-specific patterns of SA during a four-year period and their association with different sociodemographic and occupational factors among all individuals of working ages who were injured as a pedestrian. METHODS: A nationwide register-based study, including all individuals aged 20-59 and living in Sweden, who in 2014-2016 had in- or specialized outpatient healthcare after a new traffic-related accident as a pedestrian. Diagnosis-specific SA (> 14\ua0days) was assessed weekly from one year before the accident up until three years after the accident. Sequence analysis was used to identify patterns (sequences) of SA, and cluster analysis to form clusters of individuals with similar sequences. Odds ratios (ORs) with 95% confidence intervals (CIs) for association of the different factors and cluster memberships were estimated by multinomial logistic regression. RESULTS: In total, 11,432 pedestrians received healthcare due to a traffic-related accident. Eight clusters of SA patterns were identified. The largest cluster was characterized by no SA, three clusters had different SA patterns due to injury diagnoses (immediate, episodic, and later). One cluster had SA both due to injury and other diagnoses. Two clusters had SA due to other diagnoses (short-term and long-term) and one cluster mainly consisted of individuals with disability pension (DP). Compared to the cluster "No SA", all other clusters were associated with older age, no university education, having been hospitalized, and working in health and social care. The clusters "Immediate SA", "Episodic SA" and "Both SA due to injury and other diagnoses" were also associated with higher odds of pedestrians who sustained a fracture. CONCLUSIONS: This nationwide study of the working-aged pedestrians observed diverging patterns of SA after their accident. The largest cluster of pedestrians had no SA, and the other seven clusters had different patterns of SA in terms of diagnosis (injury and other diagnoses) and timing of SA. Differences were found between all clusters regarding sociodemographic and occupational factors. This information can contribute to the understanding of long-term consequences of road traffic accidents

Sickness absence and disability pension among injured working-aged pedestrians - a population-based Swedish register study

Background: The knowledge is scarce about sickness absence (SA) and disability pension (DP) among pedestrians injured in a traffic-related accident, including falls. Thus, the aim was to explore the frequencies of types of accidents and injuries and their association with SA and DP among working-aged individuals.Methods: A nationwide register-based study, including all individuals aged 16-64 and living in Sweden, who in 2010 had in- or specialized outpatient healthcare after a new traffic-related accident as a pedestrian. Information on age, sex, sociodemographics, SA, DP, type of accident, injury type, and injured body region was used. Frequencies of pedestrians with no SA or DP, with ongoing SA or full-time DP already at the time of the accident, and with a new SA spell >14 days in connection to the accident were analyzed. Crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for new SA were estimated by logistic regression.Results: In total, 5576 pedestrians received healthcare due to a traffic-related accident (of which 75% were falls, with half of the falls related to snow and ice). At the time of the accident, 7.5% were already on SA and 10.8% on full-time DP, while 20% started a new SA spell. The most common types of injuries were fractures (45%) and external injuries (30%). The body region most frequently injured was the lower leg, ankle, foot, and other (in total 26%). Older individuals had a higher OR for new SA compared with younger (OR 1.91; 95% CI 1.44-2.53, for ages: 45-54 vs. 25-34). The injury type with the highest OR for new SA, compared with the reference group external injuries, was fractures (9.58; 7.39-12.43). The injured body region with the highest OR for new SA, compared with the reference group head, face, and neck, was lower leg, ankle, foot, and other (4.52; 2.78-7.36).Conclusions: In this explorative nationwide study of the working-aged pedestrians injured in traffic-related accidents including falls, one fifth started a new SA spell >14 days. Fractures, internal injuries, collisions with motor vehicle, and falls related to snow and ice\ua0had the\ua0strongest associations\ua0with new SA

Bicycle crashes and sickness absence - A population-based Swedish register study of all individuals of working ages

Background: In recent years, bicycle injuries have increased, yet little is known about the impact of such injures on sickness absence (SA) and disability pension (DP). The aim was to explore SA and DP among individuals of working ages injured in a bicycle crash. Method: A nationwide register-based study, including all individuals aged 16-64 years and living in Sweden, who in 2010 had in- or specialized out-patient healthcare (including emergency units) after a bicycle crash. Information on age, sex, sociodemographics, SA, DP, crash type, injury type, and injured body region was used. We analyzed individuals with no SA or DP, with ongoing SA or full-time DP already at the time of the crash, and with new SA > 14 days in connection to the crash. Crude and adjusted odds ratios (OR) with 95% confidence intervals for new SA were estimated by logistic regression. Results: In total, 7643 individuals had healthcare due to a new bicycle crash (of which 85% were single-bicycle crashes). Among all, 10% were already on SA or full-time DP at the time of the crash, while 18% had a new SA spell. The most common types of injuries were external injuries (38%) and fractures (37%). The body region most frequently injured was the upper extremities (43%). Women had higher OR (1.40; 1.23-1.58) for new SA than men, as did older individuals compared with younger (OR 2.50; 2.02-3.09, for ages: 55-64 vs. 25-34). The injury types with the highest ORs for new SA, compared with the reference group external injuries was fractures (8.04; 6.62-9.77) and internal injuries (7.34; 3.67-14.66). Individuals with traumatic brain injury and injuries to the vertebral column and spinal cord had higher ORs for SA compared with other head, face, and neck injuries (2.72; 1.19-6.22 and 3.53; 2.24-5.55, respectively). Conclusions: In this explorative nationwide study of new bicycle crashes among individuals of working ages, 18% had a new SA spell in connection to the crash while 10% were already on SA or DP. The ORs for new SA were higher among women, older individuals, and among individuals with a fracture

Plastic recycling plant as a point source of microplastics to sediment and macroinvertebrates in a remote stream

Microplastic is now ubiquitous in freshwater, sediment and biota, globally. This is as a consequence of inputs from, for example, waste mismanagement, effluents from wastewater treatment plants and surface runoff from agricultural areas. In this study, we investigated point source pollution of plastic to an upland stream, originating from a recycling plant that recycles polyethylene film in a remote area of Norway. Sediment (~2 kg) and macroinvertebrates (549 individuals in total) were sampled at one site upstream and two sites downstream of the recycling plant to study microplastic deposition and food web uptake. In total, 340 microplastic films were identified through a combination of visual and µFTIR analysis in the sediment samples. This corresponded to a concentration of 0.23 (± 0.057) items per g sediment upstream of the plastic recycling plant and 0.45 (± 0.017) and 0.58 (± 0.34) items per g downstream. The dominant plastic polymer was polyethylene, which increased significantly downstream of the plastic recycling plant. This indicates the role of the plastic recycling plant as a point source for microplastic in this catchment. Among the three sites investigated, a fairly constant concentration of polypropylene was found, indicating a diffuse source of polypropylene films across the catchment possibly relating to low-intensity agricultural land-use. Low levels of polyethylene were also observed upstream, which may be linked to either local or longer-distance atmospheric transport. Despite the considerable presence of microplastic in sediments, concentrations in macroinvertebrates were extremely low with only a single microplastic particle identified in the total of 549 macroinvertebrates—belonging to three different feeding groups—investigated. Our study suggests that: 1) microplastic pollution can be transferred to remote areas as unintended losses from recycling facilities, 2) remote areas with limited land-use pressure still have detectable levels of microplastic and 3) microplastic is only taken up by stream macroinvertebrates to a limited degree despite relatively high sediment concentrations, and thus there are no strong indications for ecological risks posed by microplastic to this ecological group at this location.publishedVersio

Trends in Diagnosis-Specific Work Disability Before and After Stroke : A Longitudinal Population-Based Study in Sweden

Background-Although a stroke event often leads to work disability, diagnoses behind work disability before and after stroke are largely unknown. We examined the pre-event and postevent trends in diagnosis-specific work disability among patients of working age. Methods and Results-We included all new nonfatal stroke events in 2006-2008 from population-based hospital registers in Sweden among women and men aged 25 to 60 years (n=12 972). Annual days of diagnosis-specific work disability were followed for 4 years before and after stroke. Repeated measures negative binomial regression models using the generalized estimating equations method were fitted to examine trends in diagnosis-specific work disability before and after the event. Already during the 4 pre-event years, work disability attributed to circulatory diseases increased among women (rate ratio, 1.99; 95% confidence interval, 1.68-2.36) and men (rate ratio, 2.20; 95% confidence interval, 1.88-2.57). Increasing trends before stroke were also found for work disability attributed to mental disorders, musculoskeletal diseases, neoplasms, diseases of the nervous, respiratory, and digestive systems, injuries, and diabetes mellitus. As expected, a sharp increase in work disability days attributed to circulatory diseases was found during the first year after the event among both sexes. Overall, during 4 years after the stroke, there was a decreasing trend for circulatory diseases and injuries, whereas the trend was increasing for nervous diseases and diabetes mellitus. Conclusions-Work disability attributed to several mental and somatic diagnoses is higher already before a stroke event.Peer reviewe

Trends in diagnosis-specific work disability before and after ischaemic heart disease : a nationwide population-based cohort study in Sweden

Objectives We examined trends of diagnosis-specific work disability before and after ischaemic heart disease (IHD). Design Participants were followed 4 years before and 4 years after an IHD event for diagnosis-specific work disability (sickness absence and disability pension). Setting and participants A Swedish population-based cohort study using register data on all individuals aged 25-60 years, living in Sweden, and who suffered their first IHD event in 2006-2008 (n=23 971) was conducted. Results Before the event, the most common diagnoses of work disability were musculoskeletal disorders (21 annual days for men and 44 for women) and mental disorders (19 men and 31 for women). After multivariable adjustments, we observed a fivefold increase (from 12 to 60 days) in work disability due to diseases of the circulatory system in the first postevent year compared with the last pre-event year among men. Among women, the corresponding increase was fourfold (from 14 to 62 days). By the second postevent year, the number of work disability days decreased significantly compared with the first postevent year among both sexes (to 19 days among men and 23 days among women). Among women, mean days of work disability due to diseases of the circulatory system remained at a higher level than among men during the postevent years. Work disability risk after versus before an IHD event was slightly higher among men (rate ratio (RR) 2.49; 95% CI 2.36 to 2.62) than among women (RR 2.29, 95% CI 2.12 to 2.49). When pre-event long-term work disability was excluded, diseases of the circulatory system were the most prevalent diagnosis for work disability after an IHD event among both men and women. Conclusions An IHD event was strongly associated with an increase in work disability due to diseases of the circulatory system, especially among men and particularly in the first postevent year.Peer reviewe

Permanent work disability before and after ischaemic heart disease or stroke event : a nationwide population-based cohort study in Sweden

Objectives We examined the risk of disability pension before and after ischaemic heart disease (IHD) or stroke event, the burden of stroke compared with IHD and which factors predicted disability pension after either event. Design A population-based cohort study with follow-up 5 years before and after the event. Register data were analysed with general linear modelling with binary and Poisson distributions including interaction tests for event type (IHD/stroke). Setting and participants All people living in Sweden, aged 25-60 years at the first event year, who had been living in Sweden for 5 years before the event and had no indication of IHD or stroke prior to the index event in 2006-2008 were included, except for cases in which death occurred within 30 days of the event. People with both IHD and stroke were excluded, resulting in 18 480 cases of IHD (65%) and 9750 stroke cases (35%). Primary outcome measures Disability pension. Results Of those going to suffer IHD or stroke event, 25% were already on disability pension a year before the event. The adjusted OR for disability pension at first postevent year was 2.64-fold (95% CI 2.25 to 3.11) for people with stroke compared with IHD. Economic inactivity predicted disability pension regardless of event type (OR=3.40; 95% CI 2.85 to 4.04). Comorbid mental disorder was associated with the greatest risk (OR=3.60; 95% CI 2.69 to 4.83) after an IHD event. Regarding stroke, medical procedure, a proxy for event severity, was the largest contributor (OR=2.27, 95% CI 1.43 to 3.60). Conclusions While IHD event was more common, stroke involved more permanent work disability. Demographic, socioeconomic and comorbidity-related factors were associated with disability pension both before and after the event. The results help occupational and other healthcare professionals to identify vulnerable groups at risk for permanent labour market exclusion after such an event.Peer reviewe