Short-term effects of ambient particulates and gaseous pollutants on the incidence of transient ischaemic attack and minor stroke: a case-crossover study

BACKGROUND

While several studies have investigated the effects of short-term air pollution on cardiovascular disease, less is known about its effects on cerebrovascular disease, including stroke and transient ischaemic attack (TIA). The aim of the study was to assess the effects of short-term variation in air pollutants on the onset of TIA and minor stroke.

METHODS

We performed secondary analyses of data collected prospectively in the North West of England in a multi-centre study (NORTHSTAR) of patients with recent TIA or minor stroke. A case-crossover study was conducted to determine the association between occurrence of TIA and the concentration of ambient PM10 or gaseous pollutants.

RESULTS

A total of 709 cases were recruited from the Manchester (n = 335) and Liverpool (n = 374) areas. Data for the Manchester cohort showed an association between ambient nitric oxide (NO) and risk of occurrence of TIA and minor stroke with a lag of 3 days (odds ratio 1.06, 95% CI: 1.01 - 1.11), whereas negative association was found for the patients from Liverpool. Effects of similar magnitude, although not statistically significant, were generally observed with other pollutants. In a two pollutant model the effect of NO remained stronger and statistically significant when analysed in combination with CO or SO2, but was marginal in combination with NO2 or ozone and non-significant with PM10. There was evidence of effect modification by age, gender and season.

CONCLUSIONS

Our data suggest an association between NO and occurrence of TIA and minor stroke in Greater Manchester.

Cases of occupational dermatitis and asthma in beauticians that were reported to The Health and Occupation Research (THOR) network from 1996 to 2011

BACKGROUND

Beauticians are exposed to many potential allergens in their occupation.

AIM

To identify the sources of occupational skin and respiratory disease reported in beauticians, with an emphasis on acrylate chemicals, and to investigate the trends over time.

METHODS

We used the Health and Occupation Research (THOR) database to identify occupational disease in beauticians between 1996 and 2011. Trend analysis was carried out to look for any change in the allergens reported over this period.

RESULTS

In total, 257 cases of contact dermatitis (CD) in beauticians were identified, which were associated with 502 suspected agents. The most frequently cited source of allergic CD was acrylate chemicals. The trend analysis showed a small average annual percentage increase in work-related CD in beauticians for all agents (1.1%; 95% CI -2.5 to 4.9). There was a small decrease in cases in which acrylates were not cited (-1.7%; 95% CI -5.9 to 2.7), and a statistically significant increase when acrylates were cited (7.4%; 95% CI 0.9 to 14.4). There were 11 cases of occupational asthma.

CONCLUSION

We found an increase in cases of occupational dermatitis associated with acrylates in beauticians over a 15-year period, and describe other causes of occupational dermatitis.

Elevated N3-methylpurine-DNA glycosylase DNA repair activity is associated with lung cancer

Tobacco smoke contains a range of chemical agents that can alkylate DNA. DNA repair proteins such as N3-methylpurine-DNA glycosylase (MPG) provide protection against cell killing and mutagenicity by removing lesions such as N7-methylguanine and N3-methyladenine. However, high levels of MPG activity in transfected mammalian cells in vitro have also been associated with increased genotoxicity. The aim of this study was to examine to what extent inter-individual differences in MPG activity modify susceptibility to lung cancer. Incident cases of lung cancer (n=51) and cancer free controls (n=88) were recruited from a hospital bronchoscopy unit. Repair activity was determined in a nuclear extract of peripheral blood mononuclear cells, using a [(32)P]-based oligonucleotide cleavage assay (MPG substrate 5'-CCGCTɛAGCGGGTACCGAGCTCGAAT; ɛA=ethenoadenine). MPG activity was not related to sex or smoking status but was significantly higher in cases compared to controls (4.21±1.67 fmol/μg DNA/h vs 3.47±1.35 fmol/μg DNA/h, p=0.005). After adjustment for age, sex, presence of chronic respiratory disease and smoking duration, patients in the highest tertile of MPG activity had a three fold increased probability of lung cancer (OR 3.00, 95% CI 1.16-7.75) when compared to those patients in the lowest tertile. These results suggest that elevated MPG activity is associated with lung cancer, possibly by creating an imbalance in the base excision repair pathway.

Modelling air pollution for epidemiologic research--part II: predicting temporal variation through land use regression

Over recent years land use regression (LUR) has become a frequently used method in air pollution exposure studies, as it can model intra-urban variation in pollutant concentrations at a fine spatial scale. However, very few studies have used the LUR methodology to also model the temporal variation in air pollution exposure. The aim of this study is to estimate annual mean NO(2) and PM(10) concentrations from 1996 to 2008 for Greater Manchester using land use regression models. The results from these models will be used in the Manchester Asthma and Allergy Study (MAAS) birth cohort to determine health effects of air pollution exposure. The Greater Manchester LUR model for 2005 was recalibrated using interpolated and adjusted NO(2) and PM(10) concentrations as dependent variables for 1996-2008. In addition, temporally resolved variables were available for traffic intensity and PM(10) emissions. To validate the resulting LUR models, they were applied to the locations of automatic monitoring stations and the estimated concentrations were compared against measured concentrations. The 2005 LUR models were successfully recalibrated, providing individual models for each year from 1996 to 2008. When applied to the monitoring stations the mean prediction error (MPE) for NO(2) concentrations for all stations and years was -0.8μg/m³ and the root mean squared error (RMSE) was 6.7μg/m³. For PM(10) concentrations the MPE was 0.8μg/m³ and the RMSE was 3.4μg/m³. These results indicate that it is possible to model temporal variation in air pollution through LUR with relatively small prediction errors. It is likely that most previous LUR studies did not include temporal variation, because they were based on short term monitoring campaigns and did not have historic pollution data. The advantage of this study is that it uses data from an air dispersion model, which provided concentrations for 2005 and 2010, and therefore allowed extrapolation over a longer time period.

Pesticide exposure and screen-positive neuropsychiatric disease in British sheep farmers

BACKGROUND

Epidemiological evidence linking low dose pesticide exposure and chronic ill-health in UK sheep farmers is limited. Our aim was to examine whether neuropsychiatric disorders were associated with low dose chronic and/or more acute pesticide exposure in sheep farmers.

METHODS

A cohort of British farmers working in the 1970s was sent a screening questionnaire which asked about their health and work history. The prevalence of screen-positive depression, dementia, Parkinsonism and neuropathy was determined using a priori algorithms. Self-reported pesticide exposure was assessed by whether the participant had ever handled the pesticide concentrate (for low dose chronic exposure) or sought advice for pesticide poisoning (acute exposure) and participants categorised into those with only acute or chronic exposure, those with both acute and chronic exposure and those with neither acute nor chronic exposure. Associations between acute and chronic pesticide exposure, and screen-positive ill-health were determined after adjustment for demographic, lifestyle, occupation and somatic severity scores and other variables.

RESULTS

In those participants, who had never sought advice for pesticide poisoning, handling the pesticide concentrate for treating sheep was associated with elevated ORs for screen-positive neuropathy (ORadi 1.57 95%CI 0.97-2.54) and Parkinsonism (ORadj 1.56 95%CI 0.95-2.56) but not depression or dementia. In those participants who had handled the pesticide concentrate, seeking advice for pesticide poisoning was associated with screen-positive depression (Odds ratio, ORadj=9.97 95%CI 4.76-20.8 ), dementia (OR=6.94 95%CI 3.44-14.0), Parkinsonism (ORadj=4.77 95% 2.39-9.52), and neuropathy (ORadj=4.77 95%CI 2.39-9.52). Adjustment for somatic severity score modified little the associations with pesticide handling in those not acutely exposed but reduced the ORs for seeking advice for pesticide poisoning in those exposed chronically. Furthermore, stratification of results based upon somatic severity score indicated that the highest ORs for handling the pesticide concentrate associated with neuropathy and Parkinsonism were found in those participants whose somatic score was minimal.

CONCLUSIONS

Results are consistent with low-dose exposure to pesticides being associated with screen-positive neuropathy and Parkinsonism but the stronger associations between seeking advice for pesticide poisoning and screen-positive ill-health suggest that acute pesticide exposure remains an important determinant of ill-health. Further work is required to better delineate to what extent low dose exposures may contribute to ill-health in populations without acute exposures. Somatising tendency does not appear to play an important role in this population.

The validity and reliability of diagnoses of work-related mental ill-health

OBJECTIVES

To establish the reliability and validity of work-related mental ill-health diagnoses.

BACKGROUND

A UK-based surveillance scheme for work-related ill-health involving occupational physicians (OPs) reporting suggests that mental ill-health incidence is increasing by around 13% per year, with anxiety, depression and "other work-related stress" being the most common diagnoses. There have been no studies of the validity and reliability of such diagnoses. Given the existence of a large network of psychiatrists (PSYs) also involved in surveillance of work-related ill-health, an opportunity arose to measure the concurrent validity and reliability of work-related mental ill-health diagnoses.

METHODS

100 anonymised summaries of cases previously reported by OPs or PSYs were collected; each was sent to 5 PSYs and 5 OPs, who assigned a diagnosis and judged whether the case was work-related. Concurrent validity of the ill-health aspect of the diagnoses, and of the opinion as to work-relatedness, was assessed by comparing the overall classifications of cases by OPs and PSYs. Reliability of the diagnostic classification was measured by kappa matrices.

RESULTS

Diagnostic proportions for PSYs and OPs demonstrated good agreement for anxiety, depression, anxiety plus depression and "stress" (11%, 34%, 27%, 14%) and (14%, 30%, 27%, 17%), respectively. In both groups, kappa coefficients were high for a psychotic diagnosis (0.78, 95% CI: 0.74 to 0.83), but not as high for anxiety (0.27, 95% CI: 0.23 to 0.32), depression (0.34, 95% CI: 0.29 to 0.38) and "stress" (0.15, 95% CI: 0.10 to 0.19). The odds ratio of classifying a case as work-related among PSYs compared to OPs was 2.39 (95% CI: 1.68 to 3.38), p<0.001.

CONCLUSIONS

The overall agreement between OPs and PSYs on mental ill-health diagnoses suggests that OP diagnoses are valid for epidemiological purposes. However, the within-group reliability of the diagnosis "stress" is low. Given differences in judgements about work-relatedness, further research is needed to investigate this aspect of a diagnosis.

On the importance of primary and community healthcare in relation to global health and environmental threats: lessons from the COVID-19 crisis

In the course of the COVID-19 pandemic, it has become clear that primary healthcare systems play a critical role in clinical care, such as patient screening, triage, physical and psychological support and also in promoting good community advice and awareness in coordination with secondary healthcare and preventive care. Because of the role of social and environmental factors in COVID-19 transmission and burden of disease, it is essential to ensure that there is adequate coordination of population-based health services and public health interventions. The COVID-19 pandemic has shown the primary and community healthcare (P&CHC) system’s weaknesses worldwide. In many instances, P&CHC played only a minor role, the emphasis being on hospital and intensive care beds. This was compounded by political failures, in supporting local community resilience. Placing community building, social cohesion and resilience at the forefront of dealing with the COVID-19 crisis can help align solutions that provide a vision of ‘planetary health’. This can be achieved by involving local well-being and participation in the face of any pervasive health and environmental crisis, including other epidemics and large-scale ecological crises. This paper proposes that P&CHC should take on two critical roles: first, to support local problem-solving efforts and to serve as a partner in innovative approaches to safeguarding community well-being; and second, to understand the local environment and health risks in the context of the global health perspective. We see this as an opportunity of immediate value and broad consequence beyond the control of the COVID-19 pandemic.

Physicians' beliefs in the assessment of work attribution when reporting musculoskeletal disorders

BACKGROUND

There is considerable uncertainty about work-relatedness and musculoskeletal disorders in general, and it is also not clear how physicians decide whether work has caused a disorder in an individual patient.

AIMS

To investigate physicians' beliefs about assessment of occupational attribution for work-related musculoskeletal disorders.

METHODS

A questionnaire survey was sent to 526 occupational physicians and 248 rheumatologists on: characteristics of cases seen, assessment of work attribution, definition of work-relatedness and threshold for case reporting. Continuous variables were analysed by mean, standard deviation, an independent two-sample t-test and the Mann-Whitney test. Mean and median values were calculated and Spearman's rank test was applied to ranked data.

RESULTS

Questionnaires were completed by 68% occupational physicians and 64% rheumatologists. Both groups of physicians believed that 'history of onset in relation to workplace changes' and 'symptoms consistent with work exposure' were the most important factors suggesting work attribution. They considered that the most important objective of a reporting scheme was detection of trends in disease incidence and that the most suitable criteria for defining work-relatedness was the probability that exposure at work 'more likely than not' caused the condition (mean 0.73; SD=0.17), in a perceived likelihood scale (0-1).

CONCLUSION

There was a strong agreement between occupational physicians and rheumatologists on questions about work-relatedness and musculoskeletal disorders. The level of probability for concluding work-relatedness has been quantified.

Medium-density fibreboard and occupational asthma. A case series

BACKGROUND

Medium-density fibreboard (MDF) is a wood composite material, composed primarily of softwood, bonded with a synthetic formaldehyde-based resin. It is increasingly used, as it has various advantages over natural woods.

METHODS

Enquiry of the national reporting scheme data and three case reports were used to further the evidence base linking this exposure to occupational asthma (OA).

RESULTS

From 1991 to 2007, 21 cases of occupational sensitization to MDF were reported to the UK voluntary reporting scheme, Surveillance of Work Related Occupational Respiratory Disease (SWORD): 18 reported as occupational asthma (OA) and 3 as occupational rhinitis. All workers were male, with a mean age of 48 years, working in education, furniture manufacturing or joinery among other employments.

CONCLUSIONS

Whilst reporting scheme data identified relatively small numbers of cases of OA likely to be due to MDF, the evidence base supporting this link is generally lacking. The three cases presented, where OA was attributed to MDF exposure, add to this evidence.

Surveillance for work-related audiological disease in the UK: 1998-2006

BACKGROUND

Noise-induced hearing loss (NIHL) from prolonged occupational exposure to noise continues to rank among the top worldwide work-related ill-health problems.

AIMS

To provide an overview of incident cases based on work-related audiological ill-health data collected over a 9-year period from occupational physicians (OPs), audiological physicians (APs), general practitioners and otorhinolaryngologists.

METHODS

Analysis of numerator data reported by physicians to surveillance schemes within The Health and Occupation Reporting network (THOR). The actual cases were multiplied by the sampling ratio to provide estimated numerator numbers, followed by calculation of incidence rates using denominator data derived from the Labour Force Survey and from surveys of participating OPs.

RESULTS

Two thousand five hundred and eighty-two estimated cases (2584 estimated diagnoses) were received from OPs (Occupational Physicians Reporting Activity [OPRA]), and 2192 estimated cases (3208 estimated diagnoses) of work-related audiological ill-health were received from consultant APs [Occupational Surveillance Scheme for Audiological physicians (OSSA)] from 1998 to 2006. Cases where the causal agent was noise exposure (NIHL and tinnitus) made up of 95 and 97% of all cases reported to OPRA and OSSA, respectively. The annual average incidence rate for noise-induced audiological disorders was 7.9 [95% confidence interval (CI) 4.6-11.1] per 100 000 persons employed (OPRA) and 0.8 (95% CI 0.7-1.0) per 100 000 persons employed (OSSA). Workers with the highest incidence were older males employed in public administration and defence and the manufacture of metals.

CONCLUSIONS

THOR data show that diagnoses related to work-related noise exposure (NIHL/tinnitus), as reported to THOR, remain important health problems, despite preventive measures being in place.

Transgenerational metabolic determinants of fetal birth weight

BACKGROUND

Infants born with a higher birth weight have long been associated with an increased incidence of developing the metabolic syndrome starting from early childhood and persisting into adult life. Such risk factors include genetic tendencies as well as environmental factors. Of these, certain maternal anthropometric characteristics such as obesity or carbohydrate intolerance alter the intrauterine environment to one of nutritional plenty, thus impacting on intrauterine development. This hypernutrition pathway has led to the hypothesis of 'fuel mediated teratogenesis' and an obesogenic environment.

AIM

The aim was to identify a relationship across 3 generations relating to body weight and birth weight in order to identify whether a genetic and/or nutritional role are involved in the observed transmission.

METHODS/MATERIALS

The study utilized 2 clinical databases. The first consisted of a cohort of 182 women born in 1987 and who delivered a child between 2004-2010 [2nd Generation]. A total of 233 infants were born [3rd Generation]. This was further linked to another database of women who had delivered a child in 1987 [1st Generation]. The birth weight of the 2nd and 3rd generations and the pre-pregnancy body mass index (BMI) of the 1st and 2nd generation were registered as was the development of features of the metabolic syndrome in the 1st generation population. The 1st generation population was subdivided into 2 groups based on the BMI: BMI <25 kg/m2 (n=76) and BMI >=25 kg/m2 (n=106). The mean birth weights and pre-pregnancy BMI of the subsequent generations were compared using the student t-test.

RESULTS

There was no direct transgenerational link between the first generation BMI and third generation birth weight. Rather, birth weight was directly linked to maternal BMI. Furthermore in this study we also studied the presence of metabolic syndrome in first generation mothers. The presence or absence of metabolic syndrome did not cause any statistically significant difference in the birth weight of 2nd and 3rd generations.

CONCLUSIONS

This study supports previous reports that environmental factors play a key role in determining fetal birth weight. Identifying women with a higher pre-pregnancy BMI and educating them with regards to dietary modification in order to reduce body weight prior to pregnancy would contribute towards less adverse outcomes to the mother and her child in both the short and the long term.

Occupational exposure limits for therapeutic substances

Few therapeutic substances have occupational exposure limits (OELs) set by regulatory bodies and reliance is often placed on in-house OELs derived from a formula based on the therapeutic dose. This mode of derivation relies on assumptions about pharmacokinetics, pharmacodynamics and risk acceptability which might not be soundly based for occupational health purposes. Pharmacodynamic evidence shows that occupational exposure to airborne therapeutic substances can be associated with a much higher risk of an adverse health effect especially on the lungs or skin than by their therapeutic administration. Pharmacokinetic studies indicate that for certain therapeutic substances occupational exposure by inhalation results in a more rapid and complete systemic absorption than a similar dose administered (usually orally) for therapeutic purposes. These and other considerations are used to develop a systematic strategy for deriving OELs for therapeutic substances. The first stage of this consists of a qualitative assessment and ranking of likely occupational health effects. This is based on pharmacological studies, analogy and specific workplace studies. Subsequently assessment of the relevant pharmacological data together with environmental monitoring and exposure-linked health surveillance provides the quantitative data for the setting of appropriate OELs.

Occupational asthma from tafenoquine in the pharmaceutical industry: implications for QSAR

We report occupational asthma and rhinitis in a formulation pharmacist, employed in the development of tafenoquine. Tafenoquine is a new anti-malarial drug in development; the pure drug substance has an asthma hazard index of zero and previously was not known to be a respiratory sensitizing agent. The implications of this finding for the refinement of quantitative structural analysis of asthmagenic chemicals are discussed.

A comparison of population air pollution exposure estimation techniques with personal exposure estimates in a pregnant cohort

There is increasing evidence of the harmful effects for mother and fetus of maternal exposure to air pollutants. Most studies use large retrospective birth outcome datasets and make a best estimate of personal exposure (PE) during pregnancy periods. We compared estimates of personal NOx and NO2 exposure of pregnant women in the North West of England with exposure estimates derived using different modelling techniques. A cohort of 85 pregnant women was recruited from Manchester and Blackpool. Participants completed a time-activity log and questionnaire at 13-22 weeks gestation and were provided with personal Ogawa samplers to measure their NOx/NO2 exposure. PE was compared to monthly averages, the nearest stationary monitor to the participants' home, weighted average of the closest monitor to home and work location, proximity to major roads, as well as to background modelled concentrations (DEFRA), inverse distance weighting (IDW), ordinary kriging (OK), and a land use regression model with and without temporal adjustment. PE was most strongly correlated with monthly adjusted DEFRA (NO2r = 0.61, NOxr = 0.60), OK and IDW (NO2r = 0.60; NOxr = 0.62) concentrations. Correlations were stronger in Blackpool than in Manchester. Where there is evidence for high temporal variability in exposure, methods of exposure estimation which focus solely on spatial methods should be adjusted temporally, with an improvement in estimation expected to be better with increased temporal variability.

Preference of distance learning methods among post-graduate occupational physicians and hygienists

BACKGROUND

The Centre for Occupational and Environmental Health at the University of Manchester has successfully run distance-learning courses for a number of decades. These are based on hundreds of pages of (paper-based) written text, specially commissioned, packaged and distributed in eight binders. Converting printed text to an online format has the potential to improve learning through the benefits of information and communication technology as well as to save printing and distribution costs.

AIM

To determine which distance learning method is preferred by postgraduate occupational health students: paper-based text, or online text with embedded interactive questions and separate practical exercises.

METHODS

From approximately 50 paper-based textual course sub-units, one was converted to an online format, incorporating a variety of interactive text and supplemental practical exercises. Occupational medicine and hygiene students were provided with both the paper-based and online versions and asked, via anonymous postal questionnaire, a series of questions, including their preference for future course sub-units.

RESULTS

Sixty-two replies were received from 91 registered students (68% response). Apart from one student who had never tried the internet, all others described themselves as 'frequent' or 'occasional' internet users, with 78% having access both at home and work. Opinion was overwhelmingly positive with regard to ease of navigation, quality of the interactive exercises and online photo quality. Students tended to prefer multiple-choice questions and photo exercises and disliked interactive functions asking for words to complete paragraphs. Regarding preference for future teaching sub-units, the majority of students answering this question (67%) expressed a desire for mostly paper-based text supplemented with interactive online exercises.

CONCLUSION

Currently enrolled students prefer core teaching materials to remain in the printed medium, with the addition of online practical exercises to supplement learning.

A study of work-related musculoskeletal case reports to The Health and Occupation Reporting network (THOR) from 2002 to 2003

BACKGROUND

Occupational musculoskeletal disorders are frequently seen by occupational physicians and rheumatologists, and there are well-established UK-based schemes set-up for reporting these conditions. An apparent fall in case reporting for work-related musculoskeletal disorders in Great Britain to The Health and Occupation Reporting network (THOR) was observed from 2002 to 2003.

AIMS

To investigate changes in case reporting for musculoskeletal disorders sent by occupational physicians to Occupational Physicians Reporting Activity (OPRA) and by rheumatologists to Musculoskeletal Occupational Surveillance Scheme (MOSS) between 2002 and 2003.

METHODS

Musculoskeletal cases returned by more than 800 physicians from Great Britain reporting to OPRA and MOSS in 2002-2003 were analysed. Changes in reporting are described at individual physician and group levels in: numbers of participants, levels of response, and numbers of case reports by disease category and major occupational and industrial groups.

RESULTS

In 2002-2003, musculoskeletal disease was the most frequently reported major disease category in OPRA. Between 2002 and 2003, the proportion of musculoskeletal case reporting fell by 37% in OPRA, and 7% in MOSS. This fall was seen in many disease categories, across a wide range of occupations and industries. In OPRA, the greatest fall in reporting (74%) was for the category Raynaud's/Hand-Arm Vibration Syndrome/Vibration White Finger.

CONCLUSIONS

The fall in occupational musculoskeletal case reporting between 2002 and 2003 cannot be explained by internal factors within the reporting system. This observation highlights the need for systematic investigation of trends in case reporting for work-related ill-health.

Has the fit note reduced general practice sickness certification rates?

BACKGROUND

In 2010, the fit note replaced the sick note to help focus on what people are capable of doing, rather than signing patients 'off sick'.

AIMS

To compare proportions of work-related ill-health issued with sickness certification pre- and post-fit note introduction and assess sickness absence trends.

METHODS

General practitioners (GPs) report data on work-related ill-health and sickness absence via The Health and Occupation Research network in General Practice. The proportion of cases issued with sickness certification 4 years before and 3 years after the fit note introduction were compared. Changes in certification incidence rate ratios were measured over time.

RESULTS

Participating GPs reported 5517 cases of work-related ill-health. Pre-fit note introduction 50% of cases were certified sick. There was no change in the proportion of cases certified sick in the first year post-fit note, despite 13% of cases classified as 'maybe fit'. However, in the second year, the proportion of cases certified sick had reduced significantly (41%) and a larger proportion (19%) was advised on workplace adjustments. In the third year post-introduction, there was a slight rise in the proportion of cases certified sick; therefore, although there was a fall of 2% per annum in certification rates, this was not significant.

CONCLUSIONS

In the first year post-fit note introduction, modifications to work were recommended for people who would previously have been declared fit. Trends analyses showed a slight decrease in the certification rate, possibly indicating GPs will become more practised in advising on workplace adjustments.