Epidemiology of occupational hypersensitivity pneumonitis; reports from the SWORD scheme in the UK from 1996 to 2015.

OBJECTIVE: To estimate the reported incidence of occupational hypersensitivity pneumonitis (OHP) in the UK and to consider whether the pattern of attributed causation has changed over time. METHODS: All cases of OHP reported to the SWORD scheme between January 1996 and December 2015 were classified into 1 of 10 categories of the suspected agent. Cases were grouped into four 5-year time periods to examine any changing pattern in incidence or suspected causation. For each time period, the annual incidence was calculated using the estimated number of reported cases and the working population of the UK. RESULTS: Between 1996 and 2015, there were 202 actual cases of OHP reported to SWORD, equating to an estimated 818 cases, when adjusting for the sampling ratio. Over this period, the annual UK incidence was 1.4 per million workers. The mean (SD) age of reported cases was 52 (13) years, and cases were four-times more likely to be men than women. Over the study period, there was a fall in the proportion of cases reported to be due to agricultural exposures (44-12%), and an increase in cases due to metalworking fluids (MWFs, 2-45%). CONCLUSIONS: Over the last 20 years, the incidence of OHP in the UK has been ∼1-2 cases per million workers per year. Working with water-based MWFs is now the most commonly suspected causative exposure for OHP cases reported to the SWORD scheme in the UK.

UK asbestos imports and mortality due to idiopathic pulmonary fibrosis.

BACKGROUND: Previous studies have demonstrated that the rising mortality due to mesothelioma and asbestosis can be predicted from historic asbestos usage. Mortality due to idiopathic pulmonary fibrosis (IPF) is also rising, without any apparent explanation. AIMS: To compare mortality due to these conditions and examine the relationship between mortality and national asbestos imports. METHODS: Mortality data for IPF and asbestosis in England and Wales were available from the Office for National Statistics. Data for mesothelioma deaths in England and Wales and historic UK asbestos import data were available from the Health & Safety Executive. The numbers of annual deaths due to each condition were plotted separately by gender, against UK asbestos imports 48 years earlier. Linear regression models were constructed. RESULTS: For mesothelioma and IPF, there was a significant linear relationship between the number of male and female deaths each year and historic UK asbestos imports. For asbestosis mortality, a similar relationship was found for male but not female deaths. The annual numbers of deaths due to asbestosis in both sexes were lower than for IPF and mesothelioma. CONCLUSIONS: The strength of the association between IPF mortality and historic asbestos imports was similar to that seen in an established asbestos-related disease, i.e. mesothelioma. This finding could in part be explained by diagnostic difficulties in separating asbestosis from IPF and highlights the need for a more accurate method of assessing lifetime occupational asbestos exposure.

Asthma in furniture and wood processing workers: a systematic review.

BACKGROUND: Wood dust is a common cause of occupational asthma. There is potential for high exposure to wood dust during furniture and wood manufacturing processes. AIMS: To evaluate the evidence for non-neoplastic respiratory ill health associated with work in the furniture and wood manufacturing sector. METHODS: A systematic review was performed according to PRISMA guidelines. Articles were graded using SIGN (Scottish Intercollegiate Guideline Network) and MERGE (Methods for Evaluating Research Guidelines and Evidence) criteria, with data grouped by study outcome. RESULTS: Initial searches identified 1328 references, from which 55 articles were included in the review. Fourteen studies were graded A using MERGE or >2++ using SIGN. All but one paper describing airway symptoms reported an increased risk in higher wood dust exposed workers in comparison to lower or non-exposed groups. Five studies reporting asthma examined dose response; three found a positive effect. The relative risk for asthma in exposed workers in the single meta-analysis was 1.5 (95% CI 1.25-1.87). Two studies reported more obstructive lung function (forced expiratory volume in 1 s [FEV1]/forced vital capacity < 0.7) in exposed populations. Excess longitudinal FEV1 decline was reported in female smokers with high wood dust exposures in one study population. Where measured, work-related respiratory symptoms did not clearly relate to specific wood immunoglobulin E positivity. CONCLUSIONS: Work in this sector was associated with a significantly increased risk of respiratory symptoms and asthma. The evidence for wood dust exposure causing impaired lung function is less clearly established. Further study is required to better understand the prevalence, and causes, of respiratory problems within this sector.

Systematic review of respiratory case definitions in metalworking fluid outbreaks.

BACKGROUND: Since the mid-1990s, outbreaks of asthma and extrinsic allergic alveolitis (EAA) have been identified in workers exposed to metalworking fluids (MWFs). The cause of these outbreaks remains to be determined. AIMS: To identify and review all previously published occupational lung disease case definitions and diagnostic criteria that have been utilized during MWF outbreak investigations. METHODS: Respiratory outbreaks due to MWFs were identified by a systematic literature search for articles published between 1990 and October 2011. Investigations reporting the usage of disease case definitions or diagnostic criteria for respiratory disease were reviewed and summarized. RESULTS: The literature search identified 35 papers relating to 27 outbreaks of respiratory disease in MWF-exposed workers. Fourteen case definitions for MWF-related respiratory disease were identified: seven for EAA, five for occupational asthma and one each for humidifier fever and industrial bronchitis. A single paper was identified where any comparison of different disease case definitions (for EAA) had been performed. CONCLUSIONS: A range of case definitions and diagnostic criteria for MWF respiratory disease have been utilized in outbreak investigations, but the majority have been produced for individual outbreak investigations without previous validation. It may be difficult to compare the findings of future workplace studies without a more standardized approach to case identification and diagnosis.

Work-related symptoms in nail salon technicians.

BACKGROUND: Nail salons are a rapidly expanding small business sector. Environmental health practitioners have raised concerns about potential health and safety issues. AIMS: To establish the extent of work-related health issues reported by nail salon technicians, their knowledge of health and safety regulations and of the products used. METHODS: Nail technicians completed a researcher-administered questionnaire, and responses were compared to those of non-exposed office-based control subjects. RESULTS: In all, 39 of 588 nail salons approached agreed to participate (7%), with all 71 (100%) of the available nail technicians within these salons completing study questionnaires. The majority of the nail technicians (99%) had received training that had included aspects of health and safety and most reported being aware of the Control of Substances Hazardous to Health regulations (59/70, 84%) and risk assessments (65/70, 93%). Compared to the control group, the nail technicians reported statistically significant increased levels of work-related neck (OR 5.0, 95% CI 1.6-15.6), shoulder (15.0, 3.1-71.8), wrist/hand (3.6, 1.2-10.7) and lower back problems (3.5, 1.0-12.5). Work-related nasal symptoms were also significantly more common in nail technicians (6.2, 1.3-30.7). CONCLUSIONS: This study demonstrated a higher prevalence of a range of musculoskeletal problems and respiratory symptoms reported by nail technicians compared to office-based controls. An ergonomic and exposure assessment of work practices in this industry is warranted to identify the working practices associated with these symptoms, in order to inform best practice, supplement industry and regulatory guidance and develop appropriate practical work-based training.

Respiratory symptoms in insect breeders.

BACKGROUND: A number of specialist food suppliers in the UK breed and distribute insects and insect larvae as food for exotic pets, such as reptiles, amphibians and invertebrates. AIMS: To investigate the extent of work-related (WR) symptoms and workplace-specific serum IgE in workers potentially exposed to a variety of biological contaminants, including insect and insect larvae allergens, endotoxin and cereal allergens at a UK specialist insect breeding facility. METHODS: We undertook a study of respiratory symptoms and exposures at the facility, with subsequent detailed clinical assessment of one worker. All 32 workers were assessed clinically using a respiratory questionnaire and lung function. Eighteen workers consented to provide serum for determination of specific IgE to workplace allergens. RESULTS: Thirty-four per cent (11/32) of insect workers reported WR respiratory symptoms. Sensitization, as judged by specific IgE, was found in 29% (4/14) of currently exposed workers. Total inhalable dust levels ranged from 1.2 to 17.9 mg/m(3) [mean 4.3 mg/m(3) (SD 4.4 mg/m(3)), median 2.0 mg/m(3)] and endotoxin levels of up to 29435 EU/m(3) were recorded. CONCLUSIONS: Exposure to organic dusts below the levels for which there are UK workplace exposure limits can result in respiratory symptoms and sensitization. The results should alert those responsible for the health of similarly exposed workers to the potential for respiratory ill-health and the need to provide a suitable health surveillance programme.

Occupational asthma and rhinitis due to detergent enzymes in healthcare.

BACKGROUND: The use of proteolytic enzymes to improve the cleaning efficacy of washing powders was introduced in the mid 1960s. Many microbial enzymes are known to be potent respiratory sensitizers but previously there has been only one case of occupational asthma associated with workplace exposure in a healthcare worker. AIMS: To report two cases of occupational asthma associated with exposure to biological enzymes in health-care workers and related occupational cases. METHODS: Reporting of clinical case reports from three different work places. RESULTS: One case of occupational asthma and three other cases with work-related asthma or rhinitis occurred in one workplace. A single case of probable occupational asthma presented at a second workplace with another case of work-related asthma at a third workplace. Exposures occurred in areas used for cleaning medical instruments and endoscopy suites. Hygiene measurements confirmed the potential for exposure. Control measures were not in place and recognition of the hazard was missing in these workplaces. CONCLUSIONS: Detergent enzymes when used in healthcare settings should be recognized as potential respiratory sensitizers. Healthcare institutions and professional bodies that recommend the use of detergent enzymes should review their risk assessments to ensure that the most appropriate methods for preventing or reducing exposure are in place.

Chronic cough - occupational considerations.

Chronic cough is a common symptom in a wide range of respiratory conditions, and may also occur as a result of upper airway or gastro-esophageal problems. Whilst chronic cough of any cause may be exacerbated by work, in some cases it has a direct occupational cause, resulting from a harmful acute or chronic workplace exposure. Such occupational conditions may only be suspected by taking a detailed occupational history, and directly asking employed patients whether their cough improves away from work. Early and accurate diagnosis, linked with tailored drug therapy, modification of workplace exposures, and expert compensation advice is likely to offer the best outcome for this group of patients.

Approaches to the diagnosis and management of occupational asthma amongst UK respiratory physicians.

This study aimed to assess the approach to the diagnosis and management of occupational asthma amongst general (non-specialist) respiratory consultants in the UK. A random sample of 100 UK general respiratory physicians were invited to participate, and asked to provide information on their diagnostic approach to a case scenario of a patient with possible occupational asthma relating to flour exposure. Participation rates were 42% for the main part of the study. Less than half of consultants specifically reported they would ask whether symptoms improved away from work, and just over a third mentioned examining the patient. All of those interviewed recommended a chest X-ray, and 98% simple spirometry. Eighty-six per cent suggested measurement of serial peak flows, recorded for between 2 and 8 weeks, with measurements taken half-twelve hourly. Less than half advocated a specific flour allergy test, and almost one-quarter (23%) would not perform any immunological test at all. Once a diagnosis of occupational asthma was confirmed, less than two-thirds of those interviewed commented they would recommend some form of exposure reduction, and only 28% specifically stated they would offer compensation advice. The diagnosis of occupational asthma by general respiratory physicians within the UK lacks standardisation, and in some cases falls short of evidence-based best practise.

Respiratory symptoms, lung function and cell surface markers in a group of hemp fiber processors.

BACKGROUND: Hemp dust exposure is associated with byssinosis and accelerated lung loss in longitudinal studies. The immunological changes associated with hemp dust exposure are less well understood. METHODS: We studied a small group of current male hemp processors with a mean age of 43 years. Questionnaire data, lung function, serial FEV(1) and blood were collected from all workers. RESULTS: In total, seven workers (64%) complained of at least one respiratory symptom (one with byssinosis). The mean percentage predicted FEV(1) was 91.5, FVC 97.7, PEF 92.1, and FEF(25-75) 79.5. Serial FEV(1) measurements in the two workers with work-related respiratory symptoms revealed a mean change in FEV(1) on the first working day of -12.9%. This contrasted with +6.25% on the last working day. Respective values for the two workers without work-related symptoms were -1.4 and +3.2%. CONCLUSIONS: Lung function changes and abnormalities in a profile of cell surface activation markers and antibodies were noted to relate to the presence of work-related respiratory symptoms, not seen in the control group.

Differential regulation of CENP-A and histone H3 phosphorylation in G2/M.

After DNA replication, cells condense their chromosomes in order to segregate them during mitosis. The condensation process as well as subsequent segregation requires phosphorylation of histone H3 at serine 10. Histone H3 phosphorylation initiates during G2 in pericentric foci prior to H3 phosphorylation in the chromosome arms. Centromere protein A (CENP-A), a histone H3-like protein found uniquely at centromeres, contains a sequence motif similar to that around H3 Ser10, suggesting that CENP-A phosphorylation might be linked to pericentric initiation of histone H3 phosphorylation. To test this hypothesis, we generated peptide antibodies against the putative phosphorylation site of CENP-A. ELISA, western blot and immunocytochemical analyses show that CENP-A is phosphorylated at the shared motif. Simultaneous co-detection demonstrates that phosphorylation of CENP-A and histone H3 are separate events in G2/M. CENP-A phosphorylation occurs after both pericentric initiation and genome-wide stages of histone H3 phosphorylation. Quantitative immunocytochemistry reveals that CENP-A phosphorylation begins in prophase and reaches maximal levels in prometaphase. CENP-A phosphoepitope reactivity is lost during anaphase and becomes undetectable in telophase cells. Duplication of prekinetochores, detected as the doubling of CENP-A foci, occurs prior to complete histone H3 phosphorylation in G2. Mitotic phosphorylation of histone H3-family proteins shows tight spatial and temporal control, occurring in three phases: (1) pericentric H3 phosphorylation, (2) chromosome arm H3 phosphorylation and (3) CENP-A phosphorylation at kinetochores. These observations reveal new cytological landmarks characteristic of G2 progression.

Using a breastfeeding prevalence survey to identify a population for targeted programs.

Often, efforts to improve overall population health require identifying and targeting programs to specific high-risk populations. Breastfeeding is an example. In order to determine initiation and duration rates among various groups in the City of Toronto, a random sample of 434 mothers with infants at four months of age was surveyed to determine the prevalence of breastfeeding and major impacts on its duration. The study found that, overall, 83% of mothers initiated breastfeeding at birth. The greatest rate of decline occurred during the first month. At four months postpartum, 57% of mothers continued to breastfeed, including 35% who were exclusively breastfeeding and 22% who were supplementing breast milk with formula. Breastfeeding duration was related to a number of factors, including information and support, parity, education, use of formula supplements and country of birth. Specific groups are identified for targeted programs, and a number of strategies are proposed.