Sean Semple

Publications of Sean Semple

• Reduced lung function due to biomass smoke exposure in young adults in rural Nepal.

  Authors: Om P Kurmi, Graham S Devereux, W Cairns S Smith, Sean Semple, Markus F C Steiner, Padam Simkhada, Kin-Bong Hubert Lam, Jon G Ayres

  The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology. 05/2012;

  This study aimed to assess the effects of biomass smoke exposure on lung function in a Nepalese population addressing some of these methodological issues from previous studies.We carried out aThis study aimed to assess the effects of biomass smoke exposure on lung function in a Nepalese population addressing some of these methodological issues from previous studies.We carried out a cross-sectional study of adults in a population exposed to biomass smoke and a non-exposed population in Nepal. Questionnaire and lung function data were acquired along with direct measures of indoor and outdoor air quality.Ventilatory function (FEV1, FVC, FEF25-75) was significantly reduced in the population using biomass across all age groups compared to the non-biomass using population, even in the youngest (16-25) age group [mean FEV1 (95% CI) 2.65 (2.57-2.73) vs. 2.83 (2.74-2.91), p=0.004]. Airflow obstruction was twice as common among biomass users compared to liquefied petroleum gas users (8.1% vs. 3.6%, p<0.001) with similar patterns for males (7.4% vs. 3.3%, p=0.022) and females (10.8% vs. 3.8%, p<0.001) based on lower limit of normal. Smoking was a major risk factor for airflow obstruction but biomass exposure added to the risk.Exposure to biomass smoke is associated with deficits in lung function, an effect which can be detected as early as late teenage years. Biomass smoke and cigarette smoke have additive adverse effects on airflow obstruction in this setting.

• The relationship between workers' self-reported changes in health and their attitudes towards a workplace intervention: lessons from smoke-free legislation across the UK hospitality industry.

  Authors: Laura Maccalman, Sean Semple, Karen S Galea, Martie van Tongeren, Scott Dempsey, Shona Hilton, Ivan Gee, John G Ayres

  BMC public health. 05/2012; 12(1):324.

  ABSTRACT: BACKGROUND: The evaluation of smoke-free legislation (SFL) in the UK examined the impacts on exposure to second-hand smoke, workers' attitudes and changes in respiratory health. StudiesABSTRACT: BACKGROUND: The evaluation of smoke-free legislation (SFL) in the UK examined the impacts on exposure to second-hand smoke, workers' attitudes and changes in respiratory health. Studies that investigate changes in the health of groups of people often use self-reported symptoms. Due to the subjective nature it is of interest to determine whether workers' attitudes towards the change in their working conditions may be linked to the change in health they report. Bar workers were recruited before the introduction of the SFL in Scotland and England. They were asked about their attitudes towards SFL and the presence of respiratory and sensory symptoms both before SFL and one year later. Here we examine the relationship between initial attitudes and reported symptoms. RESULTS: There was no difference in the initial attitudes towards SFL between those working in Scotland and England. Bar workers who were educated to a higher level tended to be more positive towards SFL. Attitude towards SFL was not found to be related to change in reported symptoms, with the exception of respiratory symptoms reported by Scottish bar workers, where those who were initially more negative to SFL experienced a greater improvement in self-reported health. CONCLUSIONS: There was no evidence that workers who were more positive towards SFL reported greater improvements in respiratory and sensory symptoms. This may not be the case in all interventions and we recommend examining subjects' attitudes towards the proposed intervention when evaluating possible health benefits using self-reported methods.

• Secondhand smoke in cars: assessing children's potential exposure during typical journey conditions.

  Authors: Sean Semple, Andrew Apsley, Karen S Galea, Laura Maccalman, Brenda Friel, Vicki Snelgrove

  Tobacco control. 01/2012;

  ObjectiveTo measure levels of fine particulate matter in the rear passenger area of cars where smoking does and does not take place during typical real-life car journeys.MethodsFine particulateObjectiveTo measure levels of fine particulate matter in the rear passenger area of cars where smoking does and does not take place during typical real-life car journeys.MethodsFine particulate matter (PM(2.5)) was used as a marker of secondhand smoke and was measured and logged every minute of each car journey undertaken by smoking and non-smoking study participants. The monitoring instrument was located at breathing zone height in the rear seating area of each car. Participants were asked to carry out their normal driving and smoking behaviours over a 3-day period.Results17 subjects (14 smokers) completed a total of 104 journeys (63 smoking journeys). Journeys averaged 27 min (range 5-70 min). PM(2.5) levels averaged 85 and 7.4 μg/m(3) during smoking and non-smoking car journeys, respectively. During smoking journeys, peak PM(2.5) concentrations averaged 385 μg/m(3), with one journey measuring over 880 μg/m(3). PM(2.5) concentrations were strongly linked to rate of smoking (cigarettes per minute). Use of forced ventilation and opening of car windows were very common during smoking journeys, but PM(2.5) concentrations were still found to exceed WHO indoor air quality guidance (25 μg/m(3)) at some point in the measurement period during all smoking journeys.ConclusionsPM(2.5) concentrations in cars where smoking takes place are high and greatly exceed international indoor air quality guidance values. Children exposed to these levels of fine particulate are likely to suffer ill-health effects. There are increasing numbers of countries legislating against smoking in cars and such measures may be appropriate to prevent the exposure of children to these high levels of secondhand smoke.

• Secondhand smoke levels in Scottish bars 5 years on from the introduction of smoke-free legislation.

  Authors: Andrew Apsley, Sean Semple

  Tobacco control. 10/2011;

  ObjectiveTo determine current secondhand smoke (SHS) concentrations in bars previously assessed as part of an evaluation of Scottish smoke-free legislation 5 years ago.DesignComparison between SHSObjectiveTo determine current secondhand smoke (SHS) concentrations in bars previously assessed as part of an evaluation of Scottish smoke-free legislation 5 years ago.DesignComparison between SHS levels measured in 2006 and 2011 in 39 pubs in 2 Scottish cities.MethodsFine particulate matter (PM(2.5)) was measured discreetly for 30 min in each bar on one or two visits 5 years after the previous visit in May/June 2006. These 5-year follow-up visits were undertaken on the same day of the week and at approximately the same time of day.ResultsAverage PM(2.5) levels measured in a total of 51 bar visits in 2011 were 12 μg/m(3) (range 2-155 μg/m(3)) compared to 20 μg/m(3) (range 6-104 μg/m(3)) in the period immediately after the ban in 2006. Fine particulate concentrations in all but two visits in 2011 were comparable to PM(2.5) levels measured in outside ambient air on the same day, with 92% of visits (n=47) providing 30-min average PM(2.5) concentrations less than 25 μg/m(3).ConclusionsThese results are one of the longest follow-up of any national smoke-free legislation and indicate that, 5 years after introduction, compliance is high and that the legislation continues to provide bar workers and non-smoking customers protection from SHS.

• A survey of schoolchildren's exposure to secondhand smoke in Malaysia.

  Authors: Emilia Zainal Abidin, Sean Semple, Affandi Omar, Hejar A Rahman, Stephen W Turner, Jon G Ayres

  BMC public health. 08/2011; 11:634.

  There is a lack of data describing the exposure of Malaysian schoolchildren to Secondhand Smoke (SHS). The aim of this study is to identify factors influencing schoolchildren's exposures to SHS inThere is a lack of data describing the exposure of Malaysian schoolchildren to Secondhand Smoke (SHS). The aim of this study is to identify factors influencing schoolchildren's exposures to SHS in Malaysia. This cross-sectional study was carried out to measure salivary cotinine concentrations among 1064 schoolchildren (10-11 years) attending 24 schools in Malaysia following recent partial smoke-free restrictions. Parents completed questionnaires and schoolchildren provided saliva samples for cotinine assay. The geometric mean (GM) salivary cotinine concentrations for 947 non-smoking schoolchildren stratified by household residents' smoking behaviour were: for children living with non-smoking parents 0.32 ng/ml (95% CI 0.28-0.37) (n = 446); for children living with a smoker father 0.65 ng/ml (95% CI 0.57-0.72) (n = 432); for children living with two smoking parents 1.12 ng/ml (95% CI 0.29-4.40) (n = 3); for children who live with an extended family member who smokes 0.62 ng/ml (95% CI 0.42-0.89) (n = 33) and for children living with two smokers (father and extended family member) 0.71 ng/ml (95% CI 0.40-0.97) (n = 44). Parental-reported SHS exposures showed poor agreement with children's self-reported SHS exposures. Multiple linear regression demonstrated that cotinine levels were positively associated with living with one or more smokers, urban residence, occupation of father (Armed forces), parental-reported exposure to SHS and education of the father (Diploma/Technical certificate). This is the first study to characterise exposures to SHS using salivary cotinine concentrations among schoolchildren in Malaysia and also the first study documenting SHS exposure using salivary cotinine as a biomarker in a South-East Asian population of schoolchildren. Compared to other populations of similarly aged schoolchildren, Malaysian children have higher salivary cotinine concentrations. The partial nature of smoke-free restrictions in Malaysia is likely to contribute to these findings. Enforcement of existing legislation to reduce exposure in public place settings and interventions to reduce exposure at home, especially to implement effective home smoking restriction practices are required.

• Exposure to dust and endotoxin in textile processing workers.

  Authors: Priyamvada Paudyal, Sean Semple, Robert Niven, Gael Tavernier, Jonathan G Ayres

  The Annals of occupational hygiene. 12/2010; 55(4):403-9.

  Inhalation of cotton-based particulate has been associated with respiratory symptoms and overt lung disease related to endotoxin exposure in some studies. This cross-sectional study measures personalInhalation of cotton-based particulate has been associated with respiratory symptoms and overt lung disease related to endotoxin exposure in some studies. This cross-sectional study measures personal exposure to inhalable dust and endotoxin in the textile industry of Nepal. This study was conducted in four sectors (garment making, carpet making, weaving, and recycling) of the textile industry in Kathmandu, Nepal. Personal exposure to inhalable dust and airborne endotoxin was measured during a full-shift for 114 workers.   Personal exposure to cotton dust was generally low [geometric mean (GM) 0.81 mg m(-3)) compared to the UK workplace exposure limit (WEL) (2.5 mg m(-3)) but with nearly 18% (n = 20) of the workers sampled exceeding the limit. Exposures were lowest in the weaving and the garment sector (GM = 0.30 mg m(-3)), higher in the carpet sector (GM = 1.16 mg m(-3)), and highest in the recycling sector (GM = 3.36 mg m(-3)). Endotoxin exposures were high with the overall data (GM = 2160 EU m(-3)) being more than 20-fold higher than the Dutch health-based guidance value of 90 EU m(-3). The highest exposures were in the recycling sector (GM = 5110 EU m(-3)) and the weaving sector (GM = 2440 EU m(-3)) with lower levels in the garment sector (GM = 157 EU m(-3)). The highest endotoxin concentrations expressed as endotoxin units per milligram inhalable dust were found in the weaving sector (GM = 165 EU mg(-1)). There was a statistically significant correlation between inhalable dust concentrations and endotoxin concentrations (r = 0.37; P < 0.001) and this was particularly strong in the garment (r = 0.82; P = 0.004) and the carpet sector (r = 0.81; P < 0.001).   Inhalable dust exposures measured in the weaving, carpet, and garment sectors were all below the UK WEL for cotton dust. A significant proportion of the measurements from the cotton recycling sector were above the UK WEL suggesting that better hygiene control measures are required. Airborne endotoxin concentrations in all sectors were found to exceed the Dutch health-based guidance limit of 90 EU m(-3) and may be associated with respiratory health effects.

• High carbon dioxide concentrations in the classroom: the need for research on the effects of children's exposure to poor indoor air quality at school.

  Authors: Janice Miller, Sean Semple, Stephen Turner

  Occupational and environmental medicine. 11/2010; 67(11):799.

• Reconstructing past occupational exposures: how reliable are women's reports of their partner's occupation?

  Authors: Nara Tagiyeva, Sean Semple, Graham Devereux, Andrea Sherriff, John Henderson, Peter Elias, Jon G Ayres

  Occupational and environmental medicine. 11/2010; 68(6):452-6.

  Most of the evidence on agreement between self- and proxy-reported occupational data comes from interview-based studies. The authors aimed to examine agreement between women's reports of theirMost of the evidence on agreement between self- and proxy-reported occupational data comes from interview-based studies. The authors aimed to examine agreement between women's reports of their partner's occupation and their partner's own description using questionnaire-based data collected as a part of the prospective, population-based Avon Longitudinal Study of Parents and Children. Information on present occupation was self-reported by women's partners and proxy-reported by women through questionnaires administered at 8 and 21 months after the birth of a child. Job titles were coded to the Standard Occupational Classification (SOC2000) using software developed by the University of Warwick (Computer-Assisted Structured Coding Tool). The accuracy of proxy-report was expressed as percentage agreement and kappa coefficients for four-, three- and two-digit SOC2000 codes obtained in automatic and semiautomatic (manually improved) coding modes. Data from 6016 couples at 8 months and 5232 couples at 21 months postnatally were included in the analyses. The agreement between men's self-reported occupation and women's report of their partner's occupation in fully automatic coding mode at four-, three- and two-digit code level was 65%, 71% and 77% at 8 months and 68%, 73% and 76% at 21 months. The accuracy of agreement was slightly improved by semiautomatic coding of occupations: 73%/73%, 78%/77% and 83%/80% at 8/21 months respectively. While this suggests that women's description of their partners' occupation can be used as a valuable tool in epidemiological research where data from partners are not available, this study revealed no agreement between these young women and their partners at the two-digit level of SOC2000 coding in approximately one in five cases. Proxy reporting of occupation introduces a statistically significant degree of error in classification. The effects of occupational misclassification by proxy reporting in retrospective occupational epidemiological studies based on questionnaire data should be considered.

• The global burden of air pollution on mortality: the need to include exposure to household biomass fuel-derived particulates.

  Authors: Jamie Rylance, Duncan G Fullerton, Sean Semple, Jon G Ayres

  Environmental health perspectives. 10/2010; 118(10):A424; author reply A424-5.

• Acute exposure to biomass smoke causes oxygen desaturation in adult women.

  Authors: Om P Kurmi, Santosh Gaihre, Sean Semple, Jon G Ayres

  Thorax. 09/2010; 66(8):724-5.

• Outdoor air pollution is associated with rapid decline of lung function in alpha-1-antitrypsin deficiency.

  Authors: Alice M Wood, Roy M Harrison, Sean Semple, Jon G Ayres, Robert A Stockley

  Occupational and environmental medicine. 08/2010; 67(8):556-61.

  Outdoor air pollutants are associated with respiratory morbidity and mortality, but little longitudinal work has been undertaken in this area in chronic obstructive pulmonary disease (COPD). PatientsOutdoor air pollutants are associated with respiratory morbidity and mortality, but little longitudinal work has been undertaken in this area in chronic obstructive pulmonary disease (COPD). Patients with alpha-1-antitrypsin deficiency (AATD) typically exhibit faster decline of lung function than subjects with usual COPD and thus represent a group in whom studies of factors influencing decline may be more easily clarified. Decline of FEV(1) and KCO in subjects of the PiZZ genotype from the UK AATD registry were studied. Pollution levels (PM(10), ozone, sulphur dioxide, nitrogen dioxide) during the exposure window were extracted from GIS maps, matching the measurement to each patient's home address. Clinical predictors of decline were sought using generalised estimating equations, and pollutants added to these subsequently. Single pollutant models were used due to multicollinearity. In the FEV(1) decline analysis, higher baseline FEV(1) was associated with rapid decline of FEV(1) (p<0.001). High PM(10) exposure predicted more rapid decline of FEV(1) (p=0.024). In a similar analysis for KCO decline, higher baseline KCO predicted rapid decline (p<0.001) as did higher exposure to ozone (p=0.018). High PM(10) exposure also showed a trend towards this effect (p=0.056). Exposure to ozone and PM(10) predicts decline of lung function in AATD.

• Airborne endotoxin concentrations in homes burning biomass fuel.

  Authors: Sean Semple, Delan Devakumar, Duncan G Fullerton, Peter S Thorne, Nervana Metwali, Anthony Costello, Stephen B Gordon, Dharma S Manandhar, Jon G Ayres

  Environmental health perspectives. 03/2010; 118(7):988-91.

  About half of the world's population is exposed to smoke from burning biomass fuels at home. The high airborne particulate levels in these homes and the health burden of exposure to this smoke areAbout half of the world's population is exposed to smoke from burning biomass fuels at home. The high airborne particulate levels in these homes and the health burden of exposure to this smoke are well described. Burning unprocessed biological material such as wood and dried animal dung may also produce high indoor endotoxin concentrations. In this study we measured airborne endotoxin levels in homes burning different biomass fuels. Air sampling was carried out in homes burning wood or dried animal dung in Nepal (n = 31) and wood, charcoal, or crop residues in Malawi (n = 38). Filters were analyzed for endotoxin content expressed as airborne endotoxin concentration and endotoxin per mass of airborne particulate. Airborne endotoxin concentrations were high. Averaged over 24 hr in Malawian homes, median concentrations of total inhalable endotoxin were 24 endotoxin units (EU)/m(3) in charcoal-burning homes and 40 EU/m(3) in wood-burning homes. Short cooking-time samples collected in Nepal produced median values of 43 EU/m(3) in wood-burning homes and 365 EU/m(3) in dung-burning homes, suggesting increasing endotoxin levels with decreasing energy levels in unprocessed solid fuels. Airborne endotoxin concentrations in homes burning biomass fuels are orders of magnitude higher than those found in homes in developed countries where endotoxin exposure has been linked to respiratory illness in children. There is a need for work to identify the determinants of these high concentrations, interventions to reduce exposure, and health studies to examine the effects of these sustained, near-occupational levels of exposure experienced from early life.

• COPD and chronic bronchitis risk of indoor air pollution from solid fuel: a systematic review and meta-analysis.

  Authors: Om P Kurmi, Sean Semple, Padam Simkhada, W Cairns S Smith, Jon G Ayres

  Thorax. 03/2010; 65(3):221-8.

  Over half the world is exposed daily to the smoke from combustion of solid fuels. Chronic obstructive pulmonary disease (COPD) is one of the main contributors to the global burden of disease and canOver half the world is exposed daily to the smoke from combustion of solid fuels. Chronic obstructive pulmonary disease (COPD) is one of the main contributors to the global burden of disease and can be caused by biomass smoke exposure. However, studies of biomass exposure and COPD show a wide range of effect sizes. The aim of this systematic review was to quantify the impact of biomass smoke on the development of COPD and define reasons for differences in the reported effect sizes. A systematic review was conducted of studies with sufficient statistical power to calculate the health risk of COPD from the use of solid fuel, which followed standardised criteria for the diagnosis of COPD and which dealt with confounding factors. The results were pooled by fuel type and country to produce summary estimates using a random effects model. Publication bias was also estimated. There were positive associations between the use of solid fuels and COPD (OR=2.80, 95% CI 1.85 to 4.0) and chronic bronchitis (OR=2.32, 95% CI 1.92 to 2.80). Pooled estimates for different types of fuel show that exposure to wood smoke while performing domestic work presents a greater risk of development of COPD and chronic bronchitis than other fuels. Despite heterogeneity across the selected studies, exposure to solid fuel smoke is consistently associated with COPD and chronic bronchitis. Efforts should be made to reduce exposure to solid fuel by using either cleaner fuel or relatively cleaner technology while performing domestic work.

• UK smoke-free legislation: changes in PM2.5 concentrations in bars in Scotland, England, and Wales.

  Authors: Sean Semple, Martie van Tongeren, Karen S Galea, Laura MacCalman, Ivan Gee, Odette Parry, Audrey Naji, Jon G Ayres

  The Annals of occupational hygiene. 02/2010; 54(3):272-80.

  Evaluate the effect of smoke-free legislation on fine particulate [particulate matter <2.5 microm in diameter (PM(2.5))] air pollution levels in bars in Scotland, England, and Wales. Design: AirEvaluate the effect of smoke-free legislation on fine particulate [particulate matter <2.5 microm in diameter (PM(2.5))] air pollution levels in bars in Scotland, England, and Wales. Design: Air quality was measured in 106 randomly selected bars in Scotland, England, and Wales before and after the introduction of smoking restrictions. PM(2.5) concentrations were measured covertly for 30-min periods before smoke-free legislation was introduced, again at 1-2 months post-ban (except Wales) and then at 12-months post-baseline (except Scotland). In Scotland and England, overt measurements were carried out to assess bar workers' full-shift personal exposures to PM(2.5). Postcode data were used to determine socio-economic status of the bar location. PM(2.5) levels prior to smoke-free legislation were highest in Scotland (median 197 microg m(-3)), followed by Wales (median 184 microg m(-3)) and England (median 92 microg m(-3)). All three countries experienced a substantial reduction in PM(2.5) concentrations following the introduction of the legislation with the median reduction ranging from 84 to 93%. Personal exposure reductions were also within this range. There was evidence that bars located in more deprived postcodes had higher PM(2.5) levels prior to the legislation. Prior to legislation PM(2.5) concentrations within bars across the UK were much higher than the 65 microg m(-3) 'unhealthy' threshold for outdoor air quality as set by the US Environmental Protection Agency. Concentrations in Scottish and Welsh bars were, on average, two or more times greater than in English bars for which seasonal influences may be responsible. Legislation in all three countries produced improvements in indoor air quality that are consistent with other international studies.

• Dermal Exposure to Metalworking Fluids and Medium-Chain Chlorinated Paraffin (MCCP).

  Authors: John W Cherrie, Sean Semple

  The Annals of occupational hygiene. 12/2009;

  Metalworking fluids (MWF) may contain a variety of additives, including medium-chain chlorinated paraffin (MCCP). There is concern that exposure to MCCP may be associated with increased risks forMetalworking fluids (MWF) may contain a variety of additives, including medium-chain chlorinated paraffin (MCCP). There is concern that exposure to MCCP may be associated with increased risks for kidney toxicity. MCCP has been undergoing an evaluation as part of a European regulatory risk assessment and consequently it is important that an estimate is made of the likely occupational exposure. This paper reviews the available published data on dermal exposure to MWF and derives typical and reasonable worst-case (RWC) estimates of MCCP exposure. Estimates were highest for oil-based fluids (520 and 35 000 mg typical daily exposure and RWC exposure, respectively) and lowest for water-based fluids (30 and 520 mg for typical and RWC, respectively). Comparison with published inhalation exposure data suggests dermal and inhalation exposure may be of comparable magnitude.

• Solvent Exposure and Cognitive Ability at Age 67: A Follow-Up Study of the 1947 Scottish Mental Survey.

  Authors: Finlay D Dick, Victoria J Bourne, Sean Semple, Helen C Fox, Brian G Miller, Ian J Deary, Lawrence J Whalley

  Occupational and environmental medicine. 11/2009;

  OBJECTIVES: Organic solvent exposure may be associated with cognitive impairment in later life although the evidence for this association is inconsistent. This study sought to examine the associationOBJECTIVES: Organic solvent exposure may be associated with cognitive impairment in later life although the evidence for this association is inconsistent. This study sought to examine the association between organic solvent exposure and cognitive function in later life. METHODS: A prospective longitudinal study set in Aberdeen, Scotland involved 336 men and women born in 1936 who participated in the 1947 Scottish Mental Survey. Cognitive function, aged 67 years, was measured using Trail Making Test B (TMT B), digit symbol (DS), and auditory verbal learning test (AVLT). Occupational hygienists reviewed occupational histories, blind to cognitive function, and estimated lifetime solvent exposures. Multiple regression analyses were employed to explore the association between solvent exposure and cognitive performance after adjustment for confounders. RESULTS: After adjusting for childhood IQ, smoking, alcohol and sex, the solvent-exposed group took on average almost 10 seconds longer than the unexposed to complete TMT B, a highly significant difference. For DS, after adjusting for childhood IQ, smoking and gender, the exposed group scored on average two points lower than the unexposed, again highly significant. There was no evidence of an effect for cumulative solvent exposure on TMT B or DS. For AVLT there were no significant differences associated with exposure. CONCLUSIONS: This study, of subjects with generally low exposures, found no clear evidence of an association between solvent exposure and cognitive function.

• Biomass Fuel Use and Indoor Air Pollution in Homes in Malawi.

  Authors: Duncan G Fullerton, Sean Semple, Francis Kalambo, Rose Malamba, Aryo Suseno, George Henderson, Jon G Ayres, Stephen B Gordon

  Occupational and environmental medicine. 09/2009;

  BACKGROUND: Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. The work describes the nature and quantity of smoke exposure fromBACKGROUND: Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. The work describes the nature and quantity of smoke exposure from biomass fuel in Malawian homes. METHODS: Markers of indoor air quality were measured in 62 homes (31 rural and 31 urban) over a typical 24 hour period. Four different devices were used (one gravimetric device, two photometric devices (Sidepak and University of California Berkley), and a carbon monoxide (HOBO) monitor). Gravimetric samples were analysed for transition metal content. Data on cooking and lighting fuel type together with information on indicators of socio-economic status were collected by questionnaire. RESULTS: Respirable dust levels in both the urban and rural environment were high with the mean 24h average levels being 226microg/m3 (SD 206microg/m3). Data from real-time instruments indicated respirable dust concentrations were >250microg/m3 for over 1 hour per day in 52% of rural homes and 17% of urban homes. Average carbon monoxide levels were significantly higher in urban compared to rural homes (6.14ppm vs 1.87ppm; p<0.001). The transition metal content of the smoke was low, with no significant difference found between urban and rural homes. CONCLUSIONS: Indoor air pollution levels in Malawian homes are high. Further investigation is justified because the levels that we have demonstrated are hazardous and are likely to be damaging to health. Interventions should be sought to reduce exposure to concentrations less harmful to health.

• Bar workers' Health and Environmental Tobacco Smoke Exposure (BHETSE): Symptomatic improvement in bar staff following smoke-free legislation in Scotland.

  Authors: Jon G Ayres, Sean Semple, Laura Maccalman, Scott Dempsey, Shona Hilton, Finton J Hurley, Brian G Miller, Audrey Naji, Mark Petticrew

  Occupational and environmental medicine. 03/2009;

  OBJECTIVE: To examine changes in the health of bar workers after the introduction of smoke-free legislation. DESIGN: Longitudinal study following bar workers from before the introduction ofOBJECTIVE: To examine changes in the health of bar workers after the introduction of smoke-free legislation. DESIGN: Longitudinal study following bar workers from before the introduction of legislation (26th March 2006), at 2 months after introduction and again at 1 year post-baseline to control for seasonal differences. SETTING: Bars across a range of socio-economic settings in Scotland. PARTICIPANTS: 371 bar workers recruited from 72 bars. INTERVENTION: Introduction of smoke-free legislation prohibiting smoking in enclosed public places, including bars. Main outcomes measures: Change in prevalence of self-reported respiratory and sensory symptoms. RESULTS: 371 bar workers were recruited prior to introduction of the legislation. Of the 191 (51%) seen at 1-year follow-up the percentage of those reporting any respiratory symptom fell from 69 to 57% (p=0.02) and for sensory symptoms from 75 to 64% (p=0.02) following reductions in exposure. Reductions in the percentage of those reporting respiratory symptoms were greater at two months, probably due at least in part to the effect of season. Excluding respondents who reported having a cold, either at baseline or at one year, the reduction in respiratory symptoms was similar, although the reduction was greater for "any" reported sensory symptom (69% falling to 54%; p=0.011). For non-smokers (n=57) the reductions in reported symptoms were significant for phlegm production (32% to 14%, p=0.011) and red/irritated eyes (44% to 18%, p=0.001). There was no clear relationship between baseline salivary cotinine levels, or change in salivary cotinine levels, and change in symptoms. CONCLUSIONS: Bar workers in Scotland report significantly fewer respiratory and sensory symptoms one year after their working environment became smoke-free. These improvements, controlled for seasonal variations, were seen in both non-smokers and in smokers, and indicate that smoke-free working environments may have potentially important benefits even for smokers.

• Particulate matter exposure during domestic work in Nepal.

  Authors: Om P Kurmi, Sean Semple, Markus Steiner, George D Henderson, Jon G Ayres

  The Annals of occupational hygiene. 08/2008; 52(6):509-17.

  To measure particulate matter (PM) exposure of people involved in domestic work (i.e. housework by a resident, not paid work) in urban and rural Nepal, with exposure to biomass smoke in the ruralTo measure particulate matter (PM) exposure of people involved in domestic work (i.e. housework by a resident, not paid work) in urban and rural Nepal, with exposure to biomass smoke in the rural areas, and to examine the performance of photometric devices in collecting these data. This paper details the results of these measurements and derives calibration factors for two photometric devices compared to gravimetric measures. Between April 2006 and February 2007, respirable dust and PM(2.5) levels were measured over a 24-h period in 490 households in a range of urban and rural settings in the Kathmandu valley of Nepal. Sampling was carried out by photometric and gravimetric methods with the co-located gravimetric data used to derive a calibration factor for the photometric devices. The time-weighted average (TWA) (24 h) respirable dust levels measured by gravimetric sampler ranged from 13 to 2600 microg m(-3) in the rural settings and 3 to 110 microg m(-3) in the urban settings. The co-located photometric and gravimetric devices indicate that the SidePak Personal Aerosol Monitor device required a calibration factor of 0.48 and 0.51 for rural and urban data, respectively, whereas the DustTrak device required a factor of 0.31 and 0.35 for rural and urban settings to correct for the particle size and density of the biomass smoke. The photometric devices provide time history data on PM concentration levels and generally indicate two distinct peaks around a morning and early evening cooking time. Those involved in domestic work in rural Nepal are exposed to average respirable dust concentrations of approximately 1400 microg m(-3). Converted to an 8-h TWA, this equates to more than the current UK limit for respirable dust (4000 microg m(-3)). Homemakers, primarily women, spend a large proportion of their lives indoors in these high respirable dust concentrations and these exposures are likely to produce respiratory illness. Exposure can be controlled by the use of different fuel types and/or the use of flued stoves.

• Exposure to occupational carcinogens in great britain.

  Authors: John W Cherrie, Martie van Tongeren, Sean Semple

  The Annals of occupational hygiene. 12/2007; 51(8):653-64.

  INTRODUCTION: This paper describes the available exposure information for carcinogens in Great Britain and discusses some of the issues involved in using such data to inform an assessment of theINTRODUCTION: This paper describes the available exposure information for carcinogens in Great Britain and discusses some of the issues involved in using such data to inform an assessment of the attributable occupational cancer burden. METHODS: Carcinogenic agents or occupations/industries such as hairdressers were identified from the list of International Agency for Research on Cancer groups 1 and 2a evaluations and estimates of exposure prevalence for 1990-1993 were obtained for a subset of these agents/circumstances from the CARcinogen EXposure (CAREX) database, compiled as part of the Europe Against Cancer programme. Estimated prevalence of exposure was added for some carcinogenic exposure circumstances not covered by CAREX. Information about the level of exposure to chemical agents was obtained from the Health and Safety Executive's (HSE) National Exposure Database. Other information was obtained from relevant databases such as the Central Index of Dose Information for ionizing radiation or published sources. RESULTS: In total, there were 64 carcinogenic agents/circumstances identified with almost seven million people exposed in Great Britain. The top 30 entries covered 99.5% of the estimated exposed population. The CAREX data were generally higher than the comparable data on the numbers of people exposed to those agents available from the HSE, although in some individual cases there was considerable over- or underestimation of the exposure prevalence when using the CAREX database. The level of exposure varied greatly between substances and between workplaces. For some agents, e.g. radon and sunlight, there are important regional differences in exposure within the country. Exposure to carcinogenic agents in Great Britain was different from that in other countries: in some cases higher and in others lower. Exposure levels in the past in Britain were mostly greater than today. CONCLUSIONS: Generalizing risk estimates from epidemiological studies in different countries or the past to estimate the fraction of cancers attributable to work must be done with care, particularly in the case of population-based case-control studies where exposure estimates are generally crude. Better estimates of the distribution of levels and the prevalence of occupational exposure to carcinogenic substances in Great Britain are needed and systems should be put in place to track this information in the future. With commitment from all stakeholders, it is possible that by 2025 exposure to known occupational chemical carcinogens could be essentially eliminated in Great Britain.