Association between active commuting and low-grade inflammation: a population-based cross-sectional study

BACKGROUND

Prior studies suggest that physical activity lowers circulating C-reactive protein (CRP) levels. However, little is known about the association between regular active commuting, i.e. walking or cycling to work, and CRP concentrations. This study examines whether active commuting is associated with lower CRP.

METHODS

We conducted a cross-sectional study using population-based FINRISK data from 1997, 2002, 2007 and 2012. Participants were working adults living in Finland (n = 6208; mean age = 44 years; 53.6% women). We used linear and additive models adjusted for potential confounders to analyze whether daily active commuting, defined as the time spent walking or cycling to work, was associated with lower high-sensitivity (hs-) CRP serum concentrations compared with passive commuting.

RESULTS

We observed that daily active commuting for 45 min or more (vs. none) was associated with lower hs-CRP [% mean difference in the main model: -16.8%; 95% confidence interval (CI) -25.6% to -7.0%), and results were robust to adjustment for leisure-time and occupational physical activity, as well as diet. Similarly, active commuting for 15-29 min daily was associated with lower hs-CRP in the main model (-7.4; 95% CI -14.1 to -0.2), but the association attenuated to null after further adjustments. In subgroup analyses, associations were only observed for women.

CONCLUSIONS

Active commuting for at least 45 min a day was associated with lower levels of low-grade inflammation. Promoting active modes of transport may lead not only to reduced emissions from motorized traffic but also to population-level health benefits.

Increase in summertime ambient temperature is associated with decreased sick leave risk in Helsinki, Finland

OBJECTIVES

Climate change has increased attention to the health effects of high ambient temperatures and heatwaves worldwide. Both cause-specific mortality and hospital admissions are studied widely, mainly concentrating on warmer climates, but studies focusing on more subtle health effects and cold climates lack. This study investigated the effect of summertime daily ambient temperatures and heatwaves on sick leaves in the employed population in Helsinki, Finland, a Nordic country with a relatively cold climate.

METHODS

We obtained from the City of Helsinki personnel register data on sick leaves for the summer months (June-August) of 2002-2017. We estimated the overall cumulative association of all and short (maximum 3-day) sick leaves with daily mean temperature over a 21-day lag period using a negative binomial regression model coupled with a penalized distributed lag non-linear model (penalized DLNM). The association of sick leaves with heatwaves (cut-off temperature 20.8 °C), and prolonged heatwaves, was estimated using a negative binomial regression model coupled with DLNM. We adjusted the time series model for potential confounders, such as air pollution, relative humidity, time trends, and holidays.

RESULTS

Increasing daily temperature tended to be associated with decreased overall cumulative risk of sick leaves and short sick leaves over a 21-day lag period. In addition, heatwaves and prolonged heatwaves were associated with decreased overall cumulative risk of sick leaves compared to all other summer days: RR 0.87 (95 % CI 0.78 to 0.97) and RR 0.83 (95 % CI 0.70 to 0.98), respectively.

CONCLUSIONS

This research suggests that summertime daily temperatures that are high for this northern location have protective effects on the health of the working population.

Exposure to long-term source-specific transportation noise and incident breast cancer: A pooled study of eight Nordic cohorts

BACKGROUND

Environmental noise is an important environmental exposure that can affect health. An association between transportation noise and breast cancer incidence has been suggested, although current evidence is limited. We investigated the pooled association between long-term exposure to transportation noise and breast cancer incidence.

METHODS

Pooled data from eight Nordic cohorts provided a study population of 111,492 women. Road, railway, and aircraft noise were modelled at residential addresses. Breast cancer incidence (all, estrogen receptor (ER) positive, and ER negative) was derived from cancer registries. Hazard ratios (HR) were estimated using Cox Proportional Hazards Models, adjusting main models for sociodemographic and lifestyle variables together with long-term exposure to air pollution.

RESULTS

A total of 93,859 women were included in the analyses, of whom 5,875 developed breast cancer. The median (5th-95th percentile) 5-year residential road traffic noise was 54.8 (40.0-67.8) dB Lden, and among those exposed, the median railway noise was 51.0 (41.2-65.8) dB Lden. We observed a pooled HR for breast cancer (95 % confidence interval (CI)) of 1.03 (0.99-1.06) per 10 dB increase in 5-year mean exposure to road traffic noise, and 1.03 (95 % CI: 0.96-1.11) for railway noise, after adjustment for lifestyle and sociodemographic covariates. HRs remained unchanged in analyses with further adjustment for PM2.5 and attenuated when adjusted for NO2 (HRs from 1.02 to 1.01), in analyses using the same sample. For aircraft noise, no association was observed. The associations did not vary by ER status for any noise source. In analyses using <60 dB as a cutoff, we found HRs of 1.08 (0.99-1.18) for road traffic and 1.19 (0.95-1.49) for railway noise.

CONCLUSIONS

We found weak associations between road and railway noise and breast cancer risk. More high-quality prospective studies are needed, particularly among those exposed to railway and aircraft noise before conclusions regarding noise as a risk factor for breast cancer can be made.

Long-term exposure to traffic noise and risk of incident colon cancer: A pooled study of eleven Nordic cohorts

Background Colon cancer incidence is rising globally, and factors pertaining to urbanization have been proposed involved in this development. Traffic noise may increase colon cancer risk by causing sleep disturbance and stress, thereby inducing known colon cancer risk-factors, e.g. obesity, diabetes, physical inactivity, and alcohol consumption, but few studies have examined this. Objectives The objective of this study was to investigate the association between traffic noise and colon cancer (all, proximal, distal) in a pooled population of 11 Nordic cohorts, totaling 155,203 persons. Methods We identified residential address history and estimated road, railway, and aircraft noise, as well as air pollution, for all addresses, using similar exposure models across cohorts. Colon cancer cases were identified through national registries. We analyzed data using Cox Proportional Hazards Models, adjusting main models for harmonized sociodemographic and lifestyle data. Results During follow-up (median 18.8 years), 2757 colon cancer cases developed. We found a hazard ratio (HR) of 1.05 (95% confidence interval (CI): 0.99-1.10) per 10-dB higher 5-year mean time-weighted road traffic noise. In sub-type analyses, the association seemed confined to distal colon cancer: HR 1.06 (95% CI: 0.98-1.14). Railway and aircraft noise was not associated with colon cancer, albeit there was some indication in sub-type analyses that railway noise may also be associated with distal colon cancer. In interaction-analyses, the association between road traffic noise and colon cancer was strongest among obese persons and those with high NO₂-exposure. Discussion A prominent study strength is the large population with harmonized data across eleven cohorts, and the complete address-history during follow-up. However, each cohort estimated noise independently, and only at the most exposed façade, which may introduce exposure misclassification. Despite this, the results of this pooled study suggest that traffic noise may be a risk factor for colon cancer, especially of distal origin.

Cross-sectional associations of different types of nature exposure with psychotropic, antihypertensive and asthma medication

BACKGROUND

Exposure to natural environments is thought to be beneficial for human health, but the evidence is inconsistent.

OBJECTIVE

To examine whether exposure to green and blue spaces in urban environments is associated with mental and physical health in Finland.

METHODS

The Helsinki Capital Region Environmental Health Survey was conducted in 2015-2016 in Helsinki, Espoo and Vantaa in Finland (n=7321). Cross-sectional associations of the amounts of residential green and blue spaces within 1 km radius around the respondent's home (based on the Urban Atlas 2012), green and blue views from home and green space visits with self-reported use of psychotropic (anxiolytics, hypnotics and antidepressants), antihypertensive and asthma medication were examined using logistic regression models. Indicators of health behaviour, traffic-related outdoor air pollution and noise and socioeconomic status (SES) were used as covariates, the last of these also as a potential effect modifier.

RESULTS

Amounts of residential green and blue spaces or green and blue views from home were not associated with medications. However, the frequency of green space visits was associated with lower odds of using psychotropic medication (OR=0.67, 95% CI 0.55 to 0.82 for 3-4 times/week; 0.78, 0.63 to 0.96 for ≥5 times/week) and antihypertensive (0.64, 0.52 to 0.78; 0.59, 0.48 to 0.74, respectively) and asthma (0.74, 0.58 to 0.94; 0.76, 0.59 to 0.99, respectively) medication use. The observed associations were attenuated by body mass index, but no consistent interactions with SES indicators were observed.

CONCLUSIONS

Frequent green space visits, but not the amounts of residential green or blue spaces, or green and blue views from home, were associated with less frequent use of psychotropic, antihypertensive and asthma medication in urban environments.

Long-Term Exposure to Transportation Noise and Ischemic Heart Disease: A Pooled Analysis of Nine Scandinavian Cohorts

BACKGROUND

Transportation noise may induce cardiovascular disease, but the public health implications are unclear.

OBJECTIVES

The study aimed to assess exposure-response relationships for different transportation noise sources and ischemic heart disease (IHD), including subtypes.

METHODS

Pooled analyses were performed of nine cohorts from Denmark and Sweden, together including 132,801 subjects. Time-weighted long-term exposure to road, railway, and aircraft noise, as well as air pollution, was estimated based on residential histories. Hazard ratios (HRs) were calculated using Cox proportional hazards models following adjustment for lifestyle and socioeconomic risk factors.

RESULTS

A total of 22,459 incident cases of IHD were identified during follow-up from national patient and mortality registers, including 7,682 cases of myocardial infarction. The adjusted HR for IHD was 1.03 [95% confidence interval (CI) 1.00, 1.05] per 10 dB Lden for both road and railway noise exposure during 5 y prior to the event. Higher risks were indicated for IHD excluding angina pectoris cases, with HRs of 1.06 (95% CI: 1.03, 1.08) and 1.05 (95% CI: 1.01, 1.08) per 10 dB Lden for road and railway noise, respectively. Corresponding HRs for myocardial infarction were 1.02 (95% CI: 0.99, 1.05) and 1.04 (95% CI: 0.99, 1.08). Increased risks were observed for aircraft noise but without clear exposure-response relations. A threshold at around 55 dB Lden was suggested in the exposure-response relation for road traffic noise and IHD.

DISCUSSION

Exposure to road, railway, and aircraft noise in the prior 5 y was associated with an increased risk of IHD, particularly after exclusion of angina pectoris cases, which are less well identified in the registries. https://doi.org/10.1289/EHP10745.

Occupational noise exposure and risk of incident stroke: a pooled study of five Scandinavian cohorts

OBJECTIVES

To investigate the association between occupational noise exposure and stroke incidence in a pooled study of five Scandinavian cohorts (NordSOUND).

METHODS

We pooled and harmonised data from five Scandinavian cohorts resulting in 78 389 participants. We obtained job data from national registries or questionnaires and recoded these to match a job-exposure matrix developed in Sweden, which specified the annual average daily noise exposure in five exposure classes (LAeq8h): <70, 70-74, 75-79, 80-84, ≥85 dB(A). We identified residential address history and estimated 1-year average road traffic noise at baseline. Using national patient and mortality registers, we identified 7777 stroke cases with a median follow-up of 20.2 years. Analyses were conducted using Cox proportional hazards models adjusting for individual and area-level potential confounders.

RESULTS

Exposure to occupational noise at baseline was not associated with overall stroke in the fully adjusted models. For ischaemic stroke, occupational noise was associated with HRs (95% CI) of 1.08 (0.98 to 1.20), 1.09 (0.97 to 1.24) and 1.06 (0.92 to 1.21) in the 75-79, 80-84 and ≥85 dB(A) exposure groups, compared with <70 dB(A), respectively. In subanalyses using time-varying occupational noise exposure, we observed an indication of higher stroke risk among the most exposed (≥85 dB(A)), particularly when restricting analyses to people exposed to occupational noise within the last year (HR: 1.27; 95% CI: 0.99 to 1.63).

CONCLUSIONS

We found no association between occupational noise and risk of overall stroke after adjustment for confounders. However, the non-significantly increased risk of ischaemic stroke warrants further investigation.

Exposure–Response Functions for the Effects of Traffic Noise on Self-Reported Annoyance and Sleep Disturbance in Finland: Effect of Exposure Estimation Method

Large variations in transportation noise tolerance have been reported between communities. In addition to population sensitivity, exposure–response functions (ERFs) for the effects of transportation noise depend on the exposure estimation method used. In the EU, the new CNOSSOS-EU method will change the estimations of exposure by changing the assignment of noise levels and populations to buildings. This method was officially used for the first time in the strategic noise mapping performed by Finnish authorities in 2017. Compared to the old method, the number of people exposed to traffic noise above 55 dB decreased by 50%. The main aim of this study, conducted in the Helsinki Capital Region, Finland, was to evaluate how the exposure estimation method affects ERFs for road traffic noise. As an example, with a façade road traffic noise level of 65 dB, the ERF based on the highest façade noise level of the residential building resulted in 5.1% being highly annoyed (HAV), while the ERF based on the exposure estimation method that is similar to the CNOSSOS-EU method resulted in 13.6%. Thus, the substantial increase in the health effect estimate compensates for the reduction in the number of highly exposed people. This demonstrates the need for purpose–fitted ERFs when the CNOSSOS-EU method is used to estimate exposure in the health impact assessment of transportation noise.

Long-Term Exposure to Transportation Noise and Risk of Incident Stroke: A Pooled Study of Nine Scandinavian Cohorts

BACKGROUND

Transportation noise is increasingly acknowledged as a cardiovascular risk factor, but the evidence base for an association with stroke is sparse.

OBJECTIVE

We aimed to investigate the association between transportation noise and stroke incidence in a large Scandinavian population.

METHODS

We harmonized and pooled data from nine Scandinavian cohorts (seven Swedish, two Danish), totaling 135,951 participants. We identified residential address history and estimated road, railway, and aircraft noise for all addresses. Information on stroke incidence was acquired through linkage to national patient and mortality registries. We analyzed data using Cox proportional hazards models, including socioeconomic and lifestyle confounders, and air pollution.

RESULTS

During follow-up (median=19.5y), 11,056 stroke cases were identified. Road traffic noise (Lden) was associated with risk of stroke, with a hazard ratio (HR) of 1.06 [95% confidence interval (CI): 1.03, 1.08] per 10-dB higher 5-y mean time-weighted exposure in analyses adjusted for individual- and area-level socioeconomic covariates. The association was approximately linear and persisted after adjustment for air pollution [particulate matter (PM) with an aerodynamic diameter of ≤2.5μm (PM2.5) and NO2]. Stroke was associated with moderate levels of 5-y aircraft noise exposure (40-50 vs. ≤40 dB) (HR=1.12; 95% CI: 0.99, 1.27), but not with higher exposure (≥50 dB, HR=0.94; 95% CI: 0.79, 1.11). Railway noise was not associated with stroke.

DISCUSSION

In this pooled study, road traffic noise was associated with a higher risk of stroke. This finding supports road traffic noise as an important cardiovascular risk factor that should be included when estimating the burden of disease due to traffic noise. https://doi.org/10.1289/EHP8949.

Mortality risk related to heatwaves in Finland - Factors affecting vulnerability

BACKGROUND

Heatwaves are known to increase mortality. However, there is a need for more quantitative information on factors affecting sensitivity to the adverse health effects, particularly in countries with cool summer temperatures.

OBJECTIVES

We evaluated mortality risk related to heatwave days in Finland. Risk was examined by age, sex, cause of death, and place of death, including health and social care facilities and homes. Mortality was also analysed for different patient subgroups in healthcare facilities.

METHODS

Heatwaves were defined as periods when the daily average temperature exceeded the 90th percentile of that from May to August in 2000-2014 for ≥4 days. In addition to all heatwave days, risk was analysed for short (4-5 days) and long (≥10 days) heatwaves. Mortality analyses were based on linking registry data on i) daily non-accidental and cause-specific mortality and ii) admissions to a health or social care facility. Statistical analyses were conducted using generalised estimating equations for longitudinal data analysis, assuming a Poisson distribution for the daily mortality count.

RESULTS

During all heatwave days, mortality increased among those aged 65-74 years (6.7%, 95% confidence interval 2.9-10.8%) and ≥75 years (12.8%, 95% CI 9.8-15.9%). Mortality increased in both sexes, but the risk was higher in women. Positive associations were observed for deaths due to respiratory diseases, renal diseases, mental and behavioural disorders, diseases of the nervous system, and cardiovascular diseases. Overall, effects were stronger for long than short heatwaves. During all heatwave days, mortality increased in healthcare facilities in outpatients (26.9%, 95% CI 17.3-37.2%) and inpatients. Among inpatients, the risk was higher in long-term inpatients (stay in ward > 30 days, 13.1%, 95% CI 8.6-17.7%) than others (5.8%, 95% CI 2.7-9.0%). At homes, mortality increased by 8.1% (95% CI 1.9-14.6%). Elevated risk estimates were also detected for social care facilities.

CONCLUSIONS

In Finland, a cold-climate Northern country, heatwaves increase mortality risk significantly among the elderly. Women are more susceptible than men, and many chronic diseases are important risk factors. To reduce heatwave-related deaths, preparedness should be improved particularly in hospital and healthcare centre wards, where the most vulnerable are long-term inpatients. However, measures are also needed to protect the elderly at home and in social care facilities, especially during prolonged hot periods.

Self-reported health in the vicinity of five wind power production areas in Finland

In many countries, some people living in the vicinity of wind power production areas report having symptoms that they intuitively associate with wind turbines. Recently public discussions have focused especially on wind turbine infrasound. However, scientific evidence supporting an association is lacking. The aim of this study was to assess the association between exposure to wind turbines and the prevalence of self-reported symptoms, diseases and medications. A cross-sectional questionnaire study (n = 2,828) was conducted in the vicinity of five wind power production areas in Finland in 2015-2016. Each area had 3-16 turbines with a nominal power of 2.4-3.3 MW. The response rate was 50% (n = 1,411). Continuous and categorised (≤ 2.5, > 2.5-5, > 5-10 km) distance between the respondents' home and the closest wind turbine was used to represent exposure to wind turbines. Wind turbine sound pressure level outdoors could be reliably modelled only for the closest distance zone where the yearly average was 34 dB and maximum 43 dB. The data on symptoms (headache, nausea, dizziness, tinnitus, ear fullness, arrhythmia, fatigue, difficulties in falling asleep, waking up too early, anxiety, stress), diseases (hypertension, heart insufficiency, diabetes), and medications (analgesics for headache, joint/muscle pain and other pain, and medication for sleep disturbance, anxiety and depression, and hypertension) was obtained from the questionnaire. Logistic regression analyses were adjusted for age, sex, marital status, education, work situation, smoking, alcohol consumption, physical activity, body mass index, and hearing problems. Annoyance and sleep disturbance due to wind turbine noise were inversely associated with the distance to the closest wind turbine. The prevalence of symptoms, diseases and medications was essentially the same in all distance categories. In multivariate regression modelling, the odds ratio estimates were generally close to unity and statistically non-significant. Beyond annoyance and sleep disturbance, there were no consistent associations between exposure to wind turbines and self-reported health problems. The results do not support the hypothesis that broadband sound or infrasound from wind turbines could cause the proposed health problems.

Long-term exposure to ambient fine particulate matter originating from traffic and residential wood combustion and the prevalence of depression

Introduction

Air pollution has been suggested to be associated with depression. However, current evidence is conflicting, and no study has considered different sources of ambient particulate matter with an aerodynamic diameter below 2.5 µm (PM_2.5). We evaluated the associations of long-term exposure to PM_2.5 from road traffic and residential wood combustion with the prevalence of depression in the Helsinki region, Finland.

Methods

We conducted a cross-sectional analysis based on the Helsinki Capital Region Environmental Health Survey 2015–2016 (N=5895). Modelled long-term outdoor concentrations of PM_2.5 were evaluated using high-resolution emission and dispersion modelling on an urban scale and linked to the home addresses of study participants. The outcome was self-reported doctor-diagnosed or treated depression. We applied logistic regression and calculated the OR for 1 μg/m³ increase in PM_2.5, with 95% CI. Models were adjusted for potential confounders, including traffic noise and urban green space.

Results

Of the participants, 377 reported to have been diagnosed or treated for depression by a doctor. Long-term exposure to PM_2.5 from road traffic (OR=1.23, 95% CI 0.86 to 1.73; n=5895) or residential wood combustion (OR=0.78, 95% CI 0.43 to 1.41; n=5895) was not associated with the prevalence of depression. The estimates for PM_2.5 from road traffic were elevated, but statistically non-significant, for non-smokers (OR=1.38, 95% CI 0.94 to 2.01; n=4716).

Conclusions

We found no convincing evidence of an effect of long-term exposure to PM_2.5 from road traffic or residential wood combustion on depression.

Symptoms intuitively associated with wind turbine infrasound

In many countries, a certain proportion of individuals living in the vicinity of wind power areas have reported symptoms that they have intuitively associated with infrasound from wind turbines. While the reason for these symptoms remains under debate, this is the first study to describe the phenomenon by assessing the prevalence and severity of these wind turbine infrasound related symptoms as well as factors associated with being symptomatic. Four wind power areas in Finland assessed to have the most problems intuitively associated with wind turbine infrasound were selected for the study. The questionnaire was mailed to 4847 adults in four distance zones (≤ 2.5 km, > 2.5-5 km, > 5-10 km, > 10-20 km from the closest wind turbine), and 28% responded. In the closest distance zone, 15% of respondents reported having symptoms that they have intuitively associated with wind turbine infrasound. In the whole study area, the symptom prevalence was 5%. Many of the symptomatic respondents were annoyed by audible wind turbine sound and associated their symptoms also with vibration or electromagnetic field from wind turbines. One third of the symptomatic respondents rated their symptoms severe, and the symptom spectrum was very broad covering several organ systems. In multivariate models, many factors such as proximity to wind turbines, impaired health status, being annoyed by different aspects of wind turbines and considering wind turbines as a health risk were associated with having wind turbine infrasound related symptoms. Although causal relationships cannot be assessed based on a cross-sectional questionnaire study, it can be speculated that interpretations of symptoms are affected by many other factors in addition to actual exposure.

Heat, heatwaves and cardiorespiratory hospital admissions in Helsinki, Finland

Background

There is a lack of knowledge concerning the effects of heat on morbidity in Northern Europe. Therefore, this study aimed to evaluate the relationships of daily summer-time temperature and heatwaves with cardiorespiratory hospital admissions in Helsinki, Finland.

Methods

Time-series models adjusted for potential confounders such as air pollution were used to investigate the associations of daily temperature and heatwaves with cause-specific cardiorespiratory hospital admissions, during the summer months of 2000-2017. Daily number of hospitalizations was obtained from the national hospital discharge register, weather information from the Finnish meteorological institute.

Results

Heatwave-days were associated with an increased risk of pneumonia (RR: 1.17, 95%CI: 1.04-1.31), any respiratory disease in some age groups, and myocardial infarction (RR: 1.54, 95% CI: 1.12-2.12) among person 65-74 years of age. In addition, high effect estimates were observed for many types of cardiorespiratory diseases in association with heatwaves in some age-groups. In contrast, risk of arrhythmia was decreased during heatwaves (RR: 0.81, 95% CI: 0.70-0.93).

Conclusions

We found no associations and even protective associations between daily mean temperature and cardiorespiratory hospital admissions. However, our results suggest that heatwaves are a serious health threat affecting the morbidity even in the Northern climate

Key messages

Heatwaves are associated with increased risk of cardio-respiratory hospital admissions. There is a need to adapt to climate change in the public health sector also in Northern Europe to protect vulnerable population groups.

Wood stove use and other determinants of personal and indoor exposures to particulate air pollution and ozone among elderly persons in a Northern Suburb

A six-month winter-spring study was conducted in a suburb of the northern European city of Kuopio, Finland, to identify and quantify factors determining daily personal exposure and home indoor levels of fine particulate matter (PM_2.5 , diameter <2.5 µm) and its light absorption coefficient (PM_2.5abs ), a proxy for combustion-derived black carbon. Moreover, determinants of home indoor ozone (O₃ ) concentration were examined. Local central site outdoor, home indoor, and personal daily levels of pollutants were monitored in this suburb among 37 elderly residents. Outdoor concentrations of the pollutants were significant determinants of their levels in home indoor air and personal exposures. Natural ventilation in the detached and row houses increased personal exposure to PM_2.5 , but not to PM_2.5abs , when compared with mechanical ventilation. Only cooking out of the recorded household activities increased indoor PM_2.5 . The use of a wood stove room heater or wood-fired sauna stove was associated with elevated concentrations of personal PM_2.5 and PM_2.5abs , and indoor PM_2.5abs . Candle burning increased daily indoor and personal PM_2.5abs , and it was also a determinant of indoor ozone level. In conclusion, relatively short-lasting wood and candle burning of a few hours increased residents' daily exposure to potentially hazardous, combustion-derived carbonaceous particulate matter.

Traffic noise, noise annoyance and psychotropic medication use

BACKGROUND

Road-traffic noise can induce stress, which may contribute to mental health disorders. Mental health problems have not received much attention in noise research. People perceive noise differently, which may affect the extent to which noise contributes to poor mental health at the individual level. This paper aims to assess the relationships between outdoor traffic noise and noise annoyance and the use of psychotropic medication.

METHODS

We conducted a survey to assess noise annoyance and psychotropic medication among residents of the Helsinki Capital Region of Finland. We also assessed the associations of annoyance and road-traffic noise with sleep disorders, anxiety and depression. Respondents were randomly sampled from the Finnish Population registry, and data was collected using a self-administered questionnaire. Outdoor traffic noise was modelled using the Nordic prediction model. Associations between annoyance and modelled façade-noise levels with mental health outcome indicators were assessed using a binary logistic regression while controlling for socioeconomic, lifestyle and exposure-related factors.

RESULTS

A total of 7321 respondents returned completed questionnaires. Among the study respondents, 15%, 7% and 7% used sleep medication, anxiolytic and antidepressant medications, respectively, in the year preceding the study. Noise annoyance was associated with anxiolytic drug use, OR = 1.41 (95% CI: 1.02-1.95), but not with sedative or antidepressant use. There was suggestive association between modelled noise at levels higher than 60 dB and anxiolytic or antidepressant use. In respondents whose bedroom windows faced the street, modelled noise was definitively associated with antidepressant use. Noise sensitivity did not modify the effect of noise but was associated with an increased use of psychotropic medication.

CONCLUSION

We observed suggestive associations between high levels of road-traffic noise and psychotropic medication use. Noise sensitivity was associated with psychotropic medication use.

Acute effects of visits to urban green environments on cardiovascular physiology in women: A field experiment

BACKGROUND

Epidemiological studies have reported positive associations between the amount of green space in the living environment and mental and cardiovascular human health. In a search for effect mechanisms, field studies have found short-term visits to green environments to be associated with psychological stress relief. Less evidence is available on the effect of visits on cardiovascular physiology.

OBJECTIVES

To evaluate whether visits to urban green environments, in comparison to visits to a built-up environment, lead to beneficial short-term changes in indicators of cardiovascular health.

METHODS

Thirty-six adult female volunteers visited three different types of urban environments: an urban forest, an urban park, and a built-up city centre, in Helsinki, Finland. The visits consisted of 15min of sedentary viewing, and 30min of walking. During the visits, blood pressure and heart rate were measured, and electrocardiogram recorded for the determination of indicators of heart rate variability. In addition, levels of respirable ambient particles and environmental noise were monitored.

RESULTS

Visits to the green environments were associated with lower blood pressure (viewing period only), lower heart rate, and higher indices of heart rate variability [standard deviation of normal-to-normal intervals (SDNN), high frequency power] than visits to the city centre. In the green environments, heart rate decreased and SDNN increased during the visit. Associations between environment and indicators of cardiovascular health weakened slightly after inclusion of particulate air pollution and noise in the models.

CONCLUSIONS

Visits to urban green environments are associated with beneficial short-term changes in cardiovascular risk factors. This can be explained by psychological stress relief with contribution from reduced air pollution and noise exposure during the visits. Future research should evaluate the amount of exposure to green environments needed for longer-term benefits for cardiovascular health.

Biometeorological Assessment of Mortality Related to Extreme Temperatures in Helsinki Region, Finland, 1972-2014

Climate change is expected to increase heat-related and decrease cold-related mortality. The extent of acclimatization of the population to gradually-changing thermal conditions is not well understood. We aimed to define the relationship between mortality and temperature extremes in different age groups in the Helsinki-Uusimaa hospital district in Southern Finland, and changes in sensitivity of the population to temperature extremes over the period of 1972-2014. Time series of mortality were made stationary with a method that utilizes 365-day Gaussian smoothing, removes trends and seasonality, and gives relative mortality as the result. We used generalized additive models to examine the association of relative mortality to physiologically equivalent temperature (PET) and to air temperature in the 43-year study period and in two 21-year long sub-periods (1972-1992 and 1994-2014). We calculated the mean values of relative mortality in percentile-based categories of thermal indices. Relative mortality increases more in the hot than in the cold tail of the thermal distribution. The increase is strongest among those aged 75 years and older, but is somewhat elevated even among those younger than 65 years. Above the 99th percentile of the PET distribution, the all-aged relative mortality decreased in time from 18.3 to 8.6%. Among those ≥75 years old, the decrease in relative mortality between the sub-periods were found to be above the 90th percentile. The dependence of relative mortality on cold extremes was negligible, except among those ≥75 years old, in the latter period. Thus, heat-related mortality is also remarkable in Finland, but the sensitivity to heat stress has decreased over the decades.

Effects of long-range transported air pollution from vegetation fires on daily mortality and hospital admissions in the Helsinki metropolitan area, Finland

INTRODUCTION

Fine particulate matter (PM_2.5) emissions from vegetation fires can be transported over long distances and may cause significant air pollution episodes far from the fires. However, epidemiological evidence on health effects of vegetation-fire originated air pollution is limited, particularly for mortality and cardiovascular outcomes.

OBJECTIVE

We examined association between short-term exposure to long-range transported PM_2.5 from vegetation fires and daily mortality due to non-accidental, cardiovascular, and respiratory causes and daily hospital admissions due to cardiovascular and respiratory causes in the Helsinki metropolitan area, Finland.

METHODS

Days significantly affected by smoke from vegetation fires between 2001 and 2010 were identified using air quality measurements at an urban background and a regional background monitoring station, and modelled data on surface concentrations of vegetation-fire smoke. Associations between daily PM_2.5 concentration and health outcomes on i) smoke-affected days and ii) all other days (i.e. non-smoke days) were analysed using Poisson time series regression. All statistical models were adjusted for daily temperature and relative humidity, influenza, pollen, and public holidays.

RESULTS

On smoke-affected days, 10µg/m³ increase in PM_2.5 was associated with a borderline statistically significant increase in cardiovascular mortality among total population at a lag of three days (12.4%, 95% CI -0.2% to 26.5%), and among the elderly (≥65 years) following same-day exposure (13.8%, 95% CI -0.6% to 30.4%) and at a lag of three days (11.8%, 95% CI -2.2% to 27.7%). Smoke day PM_2.5 was not associated with non-accidental mortality or hospital admissions due to cardiovascular causes. However, there was an indication of a positive association with hospital admissions due to respiratory causes among the elderly, and admissions due to chronic obstructive pulmonary disease or asthma among the total population. In contrast, on non-smoke days PM_2.5 was generally not associated with the health outcomes, apart from suggestive small positive effects on non-accidental mortality at a lag of one day among the elderly and hospital admissions due to all respiratory causes following same-day exposure among the total population.

CONCLUSIONS

Our research provides suggestive evidence for an association of exposure to long-range transported PM_2.5 from vegetation fires with increased cardiovascular mortality, and to a lesser extent with increased hospital admissions due to respiratory causes. Hence, vegetation-fire originated air pollution may have adverse effects on public health over a distance of hundreds to thousands of kilometres from the fires.

Latent class analysis reveals clinically relevant atopy phenotypes in 2 birth cohorts

BACKGROUND

Phenotypes of childhood-onset asthma are characterized by distinct trajectories and functional features. For atopy, definition of phenotypes during childhood is less clear.

OBJECTIVE

We sought to define phenotypes of atopic sensitization over the first 6 years of life using a latent class analysis (LCA) integrating 3 dimensions of atopy: allergen specificity, time course, and levels of specific IgE (sIgE).

METHODS

Phenotypes were defined by means of LCA in 680 children of the Multizentrische Allergiestudie (MAS) and 766 children of the Protection against allergy: Study in Rural Environments (PASTURE) birth cohorts and compared with classical nondisjunctive definitions of seasonal, perennial, and food sensitization with respect to atopic diseases and lung function. Cytokine levels were measured in the PASTURE cohort.

RESULTS

The LCA classified predominantly by type and multiplicity of sensitization (food vs inhalant), allergen combinations, and sIgE levels. Latent classes were related to atopic disease manifestations with higher sensitivity and specificity than the classical definitions. LCA detected consistently in both cohorts a distinct group of children with severe atopy characterized by high seasonal sIgE levels and a strong propensity for asthma; hay fever; eczema; and impaired lung function, also in children without an established asthma diagnosis. Severe atopy was associated with an increased IL-5/IFN-γ ratio. A path analysis among sensitized children revealed that among all features of severe atopy, only excessive sIgE production early in life affected asthma risk.

CONCLUSIONS

LCA revealed a set of benign, symptomatic, and severe atopy phenotypes. The severe phenotype emerged as a latent condition with signs of a dysbalanced immune response. It determined high asthma risk through excessive sIgE production and directly affected impaired lung function.

Microbial secondary metabolites in homes in association with moisture damage and asthma

We aimed to characterize the presence of microbial secondary metabolites in homes and their association with moisture damage, mold, and asthma development. Living room floor dust was analyzed by LC-MS/MS for 333 secondary metabolites from 93 homes of 1-year-old children. Moisture damage was present in 15 living rooms. At 6 years, 8 children had active and 15 lifetime doctor-diagnosed asthma. The median number of different metabolites per house was 17 (range 8-29) and median sum load 65 (4-865) ng/m(2) . Overall 42 different metabolites were detected. The number of metabolites present tended to be higher in homes with mold odor or moisture damage. The higher sum loads and number of metabolites with loads over 10 ng/m(2) were associated with lower prevalence of active asthma at 6 years (aOR 0.06 (95% CI <0.001-0.96) and 0.05 (<0.001-0.56), respectively). None of the individual metabolites, which presence tended (P < 0.2) to be increased by moisture damage or mold, were associated with increased risk of asthma. Microbial secondary metabolites are ubiquitously present in home floor dust. Moisture damage and mold tend to increase their numbers and amount. There was no evidence indicating that the secondary metabolites determined would explain the association between moisture damage, mold, and the development of asthma.

Natural history of bleeding and characteristics of early bleeders among warfarin initiators - a cohort study in Finland

Aims

The demand for oral anticoagulant therapy will continue to increase in the future along with the aging of the population. This study aimed to determine the rate of bleeding requiring hospitalization and to characterize early bleeders among persons initiating warfarin therapy. Characterization of those most susceptible to early bleeding is important in order to increase the safety of warfarin initiation.

Patients and methods

Using data from nationwide health registers, we identified persons initiating warfarin therapy between January 1, 2009 and June 30, 2012, n=101,588, and followed them until hospitalization for bleeding, death, or administrative end of the study (December 31, 2012). We defined early bleeders as persons with a bleeding requiring hospitalization within 30 days since warfarin initiation.

Results

The rate of hospitalization for bleeding during a median follow-up of 1.9 years was 2.6% per person-year (95% confidence interval [CI] 2.5%–2.7%), with a peak within the first 30 days of warfarin initiation (6.5% per person-year, 95% CI 6.0%–7.1%). In a multivariable Cox proportional hazards regression analysis, early bleeders were characterized by prior bleeding (<180 days before initiation, hazard ratio [HR] =13.7, 95% CI 10.9–17.1; during 180 days–7 years before initiation, HR =1.48, 95% CI 1.15–1.90), male sex (HR =1.32, 95% CI 1.10–1.57), older age (HR =1.13, 95% CI 1.04–1.22, per 10-year increase), venous thrombosis (HR =1.83, 95% CI 1.44–2.34), pulmonary embolism (HR =1.46, 95% CI 1.11–1.91), alcohol abuse (HR =1.59, 95% CI 1.08–2.35), rheumatic disease (HR =1.40, 95% CI 1.07–1.83), and exposure to drugs with dynamic interaction mechanism with warfarin (HR =1.43, 95% CI 1.20–1.71). In age-adjusted models, Charlson comorbidity index and number of drugs predicted a graded increase in the hazard of early bleeding.

Conclusion

The rate of hospitalizations for bleeding peaked in the beginning of warfarin therapy. Early bleeders were characterized by venous thrombosis, pulmonary embolism, and factors that increase bleeding risk without affecting the international normalized ratio.

Impact of Statin Adherence on Cardiovascular Morbidity and All-Cause Mortality in the Primary Prevention of Cardiovascular Disease: A Population-Based Cohort Study in Finland

OBJECTIVES

To assess the extent to which adherence to statins is associated with the incidence of cardiovascular (CV) events and all-cause mortality in the primary prevention of CV diseases and whether different analytical approaches influence the observed associations.

METHODS

This population-based cohort study used data from Finnish registers. The cohort included 97,575 new statin users aged 45 to 75 years in 2001 to 2004 with no CV diseases at baseline. Exposure was defined as adherence to statins (proportion of days covered [PDC]). The primary outcome was any CV event or death during a 3-year follow-up. Different analytical approaches, including multivariable-adjusted Cox regression, inverse probability weighting with time-varying adherence, and propensity score calibration, were used.

RESULTS

During the first year of follow-up, 53% displayed good (PDC ≥80%), 26% had intermediate (PDC 40%-79%), and 21% exhibited poor (PDC <40%) adherence. After adjustment for sociodemographic and clinical covariates, a 25% relative risk reduction (hazard ratio [HR] 0.75; 95% confidence interval [CI] 0.71-0.79) was observed in the rate of any CV event or death among good versus poor adherers. Good adherers also had a lower incidence than poor adherers of acute coronary syndrome (HR 0.56; 95% CI 0.49-0.65) and acute cerebrovascular disease events (HR 0.67; 95% CI 0.60-0.76). The different analytical approaches achieved comparable results for all the outcomes.

CONCLUSIONS

The incidence of CV events and mortality was higher in poor versus good adherers. Different analytical methods that took into account changes in adherence and confounding at baseline did not appreciably affect the results.

Long-term effects of elemental composition of particulate matter on inflammatory blood markers in European cohorts

BACKGROUND

Epidemiological studies have associated long-term exposure to ambient particulate matter with increased mortality from cardiovascular and respiratory disorders. Systemic inflammation is a plausible biological mechanism behind this association. However, it is unclear how the chemical composition of PM affects inflammatory responses.

OBJECTIVES

To investigate the association between long-term exposure to elemental components of PM and the inflammatory blood markers high-sensitivity C-reactive protein (hsCRP) and fibrinogen as part of the European ESCAPE and TRANSPHORM multi-center projects.

METHODS

In total, 21,558 hsCRP measurements and 17,428 fibrinogen measurements from cross-sections of five and four cohort studies were available, respectively. Residential long-term concentrations of particulate matter <10μm (PM10) and <2.5μm (PM2.5) in diameter and selected elemental components (copper, iron, potassium, nickel, sulfur, silicon, vanadium, zinc) were estimated based on land-use regression models. Associations between components and inflammatory markers were estimated using linear regression models for each cohort separately. Cohort-specific results were combined using random effects meta-analysis. As a sensitivity analysis the models were additionally adjusted for PM mass.

RESULTS

A 5ng/m(3) increase in PM2.5 copper and a 500ng/m(3) increase in PM10 iron were associated with a 6.3% [0.7; 12.3%] and 3.6% [0.3; 7.1%] increase in hsCRP, respectively. These associations between components and fibrinogen were slightly weaker. A 10ng/m(3) increase in PM2.5 zinc was associated with a 1.2% [0.1; 2.4%] increase in fibrinogen; confidence intervals widened when additionally adjusting for PM2.5.

CONCLUSIONS

Long-term exposure to transition metals within ambient particulate matter, originating from traffic and industry, may be related to chronic systemic inflammation providing a link to long-term health effects of particulate matter.

Air Pollution from Road Traffic and Systemic Inflammation in Adults: A Cross-Sectional Analysis in the European ESCAPE Project

BACKGROUND

Exposure to particulate matter air pollution (PM) has been associated with cardiovascular diseases.

OBJECTIVES

In this study we evaluated whether annual exposure to ambient air pollution is associated with systemic inflammation, which is hypothesized to be an intermediate step to cardiovascular disease.

METHODS

Six cohorts of adults from Central and Northern Europe were used in this cross-sectional study as part of the larger ESCAPE project (European Study of Cohorts for Air Pollution Effects). Data on levels of blood markers for systemic inflammation-high-sensitivity C-reactive protein (CRP) and fibrinogen-were available for 22,561 and 17,428 persons, respectively. Land use regression models were used to estimate cohort participants' long-term exposure to various size fractions of PM, soot, and nitrogen oxides (NOx). In addition, traffic intensity on the closest street and traffic load within 100 m from home were used as indicators of traffic air pollution exposure.

RESULTS

Particulate air pollution was not associated with systemic inflammation. However, cohort participants living on a busy (> 10,000 vehicles/day) road had elevated CRP values (10.2%; 95% CI: 2.4, 18.8%, compared with persons living on a quiet residential street with < 1,000 vehicles/day). Annual NOx concentration was also positively associated with levels of CRP (3.2%; 95% CI: 0.3, 6.1 per 20 μg/m3), but the effect estimate was more sensitive to model adjustments. For fibrinogen, no consistent associations were observed.

CONCLUSIONS

Living close to busy traffic was associated with increased CRP concentrations, a known risk factor for cardiovascular diseases. However, it remains unclear which specific air pollutants are responsible for the association.

Road-traffic noise: annoyance, risk perception, and noise sensitivity in the Finnish adult population

Exposure to road-traffic noise commonly engenders annoyance, the extent of which is determined by factors not fully understood. Our aim was to estimate the prevalence and determinants of road-traffic noise annoyance and noise sensitivity in the Finnish adult population, while comparing the perceptions of road-traffic noise to exhausts as environmental health problems. Using a questionnaire that yielded responses from 1112 randomly selected adult Finnish respondents, we estimated road-traffic noise- and exhausts-related perceived exposures, health-risk perceptions, and self-reported annoyance on five-point scales, while noise sensitivity estimates were based on four questions. Determinants of noise annoyance and sensitivity were investigated using multivariate binary logistic regression and linear regression models, respectively. High or extreme noise annoyance was reported by 17% of respondents. Noise sensitivity scores approximated a Gaussian distribution. Road-traffic noise and exhausts were, respectively, considered high or extreme population-health risks by 22% and 27% of respondents. Knowledge of health risks from traffic noise, OR: 2.04 (1.09–3.82) and noise sensitivity, OR: 1.07 (1.00–1.14) were positively associated with annoyance. Knowledge of health risks (p < 0.045) and positive environmental attitudes (p < 000) were associated with higher noise sensitivity. Age and sex were associated with annoyance and sensitivity only in bivariate models. A considerable proportion of Finnish adults are highly annoyed by road-traffic noise, and perceive it to be a significant health risk, almost comparable to traffic exhausts. There is no distinct noise-sensitive population subgroup. Knowledge of health risks of road-traffic noise, and attitudinal variables are associated with noise annoyance and sensitivity.

Source-specific fine particulate air pollution and systemic inflammation in ischaemic heart disease patients

OBJECTIVE

To compare short-term effects of fine particles (PM2.5; aerodynamic diameter <2.5 µm) from different sources on the blood levels of markers of systemic inflammation.

METHODS

We followed a panel of 52 ischaemic heart disease patients from 15 November 2005 to 21 April 2006 with clinic visits in every second week in the city of Kotka, Finland, and determined nine inflammatory markers from blood samples. In addition, we monitored outdoor air pollution at a fixed site during the study period and conducted a source apportionment of PM2.5 using the Environmental Protection Agency's model EPA PMF 3.0. We then analysed associations between levels of source-specific PM2.5 and markers of systemic inflammation using linear mixed models.

RESULTS

We identified five source categories: regional and long-range transport (LRT), traffic, biomass combustion, sea salt, and pulp industry. We found most evidence for the relation of air pollution and inflammation in LRT, traffic and biomass combustion; the most relevant inflammation markers were C-reactive protein, interleukin-12 and myeloperoxidase. Sea salt was not positively associated with any of the inflammatory markers.

CONCLUSIONS

Results suggest that PM2.5 from several sources, such as biomass combustion and traffic, are promoters of systemic inflammation, a risk factor for cardiovascular diseases.

Arterial blood pressure and long-term exposure to traffic-related air pollution: an analysis in the European Study of Cohorts for Air Pollution Effects (ESCAPE)

BACKGROUND

Long-term exposure to air pollution has been hypothesized to elevate arterial blood pressure (BP). The existing evidence is scarce and country specific.

OBJECTIVES

We investigated the cross-sectional association of long-term traffic-related air pollution with BP and prevalent hypertension in European populations.

METHODS

We analyzed 15 population-based cohorts, participating in the European Study of Cohorts for Air Pollution Effects (ESCAPE). We modeled residential exposure to particulate matter and nitrogen oxides with land use regression using a uniform protocol. We assessed traffic exposure with traffic indicator variables. We analyzed systolic and diastolic BP in participants medicated and nonmedicated with BP-lowering medication (BPLM) separately, adjusting for personal and area-level risk factors and environmental noise. Prevalent hypertension was defined as ≥ 140 mmHg systolic BP, or ≥ 90 mmHg diastolic BP, or intake of BPLM. We combined cohort-specific results using random-effects meta-analysis.

RESULTS

In the main meta-analysis of 113,926 participants, traffic load on major roads within 100 m of the residence was associated with increased systolic and diastolic BP in nonmedicated participants [0.35 mmHg (95% CI: 0.02, 0.68) and 0.22 mmHg (95% CI: 0.04, 0.40) per 4,000,000 vehicles × m/day, respectively]. The estimated odds ratio (OR) for prevalent hypertension was 1.05 (95% CI: 0.99, 1.11) per 4,000,000 vehicles × m/day. Modeled air pollutants and BP were not clearly associated.

CONCLUSIONS

In this first comprehensive meta-analysis of European population-based cohorts, we observed a weak positive association of high residential traffic exposure with BP in nonmedicated participants, and an elevated OR for prevalent hypertension. The relationship of modeled air pollutants with BP was inconsistent.

Fish consumption, omega-3 fatty acids, and environmental contaminants in relation to low-grade inflammation and early atherosclerosis

BACKGROUND

Fish consumption and omega-3 polyunsaturated fatty acid (PUFA) intake are shown to protect from cardiovascular diseases (CVD). However, most fish contain environmental contaminants such as dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and methylmercury (MeHg) that may have adverse effects on cardiovascular health.

OBJECTIVE

Our aim was to elucidate the associations of fish consumption, omega-3 PUFAs, environmental contaminants with low-grade inflammation, early atherosclerosis, and traditional CVD risk factors.

METHODS

The Health 2000 survey participants (n=1173) represented the general Finnish population and the Fishermen study participants (n=255) represented a population with high fish consumption and high exposure to environmental contaminants. Model-adjusted geometric means and tests for linear trend were calculated for CVD risk factors by tertiles of fish consumption and serum omega-3 PUFAs, and additionally in the Fishermen study only, by tertiles of serum PCDD/F+PCB, and blood MeHg.

RESULTS

Serum triglyceride decreased across omega-3 PUFA tertiles in both sexes and studies. Insulin resistance, C-reactive protein, tumour necrosis factor α, and interleukin 6 decreased across omega-3 PUFA tertiles among the Health 2000 survey participants. Among the Fishermen study men, insulin resistance and arterial stiffness indicated by β-stiffness index tended to increase and the RR estimate for carotid artery plaque tended to decrease across tertiles of PCDD/F+PCB and MeHg.

CONCLUSION

Previously established hypotriglyceridemic and anti-inflammatory effects of omega-3 PUFAs were seen also in this study. The hypothesised favourable effect on insulin sensitivity and arterial elasticity was suggested to be counteracted by high exposure to environmental contaminants but the effect on plaque prevalence appeared not to be harmful.

Low-level exposure to ambient particulate matter is associated with systemic inflammation in ischemic heart disease patients

Short-term exposure to ambient air pollution is associated with increased cardiovascular mortality and morbidity. This adverse health effect is suggested to be mediated by inflammatory processes. The purpose of this study was to determine if low levels of particulate matter, typical for smaller cities, are associated with acute systemic inflammation. Fifty-two elderly individuals with ischemic heart disease were followed for six months with biweekly clinical visits in the city of Kotka, Finland. Blood samples were collected for the determination of inflammatory markers interleukin (IL)-1β, IL-6, IL-8, IL-12, interferon (IFN)γ, C-reactive protein (CRP), fibrinogen, myeloperoxidase and white blood cell count. Particle number concentration and fine particle (particles with aerodynamic diameters <2.5 μm (PM(2.5))) as well as thoracic particle (particles with aerodynamic diameters <10 μm (PM(10))) mass concentration were measured daily at a fixed outdoor measurement site. Light-absorbance of PM(2.5) filter samples, an indicator of combustion derived particles, was measured with a smoke-stain reflectometer. In addition, personal exposure to PM(2.5) was measured with portable photometers. During the study period, wildfires in Eastern Europe led to a 12-day air pollution episode, which was excluded from the main analyses. Average ambient PM(2.5) concentration was 8.7 μg/m(3). Of the studied pollutants, PM(2.5) and absorbance were most strongly associated with increased levels of inflammatory markers; most notably with C-reactive protein and IL-12 within a few days of exposure. There was also some evidence of an effect of particulate air pollution on fibrinogen and myeloperoxidase. The concentration of IL-12 was considerably (227%) higher during than before the forest fire episode. These findings show that even low levels of particulate air pollution from urban sources are associated with acute systemic inflammation. Also particles from wildfires may exhibit pro-inflammatory effects.

Odor annoyance near waste treatment centers: a population-based study in Finland

Decomposition of biodegradable waste in municipal waste centers may produce odor emissions and subsequently cause discomfort to nearby residents. The public health importance of the resulting nuisance has not been sufficiently characterized. The aim of this study was to study the perception and annoyance of waste odor among residents in relation to distance from the large-scale source. In 2006, 1142 randomly selected residents living within 5 km from the boundaries of five waste treatment centers were interviewed by telephone. These centers were landfilling municipal waste and composting source-separated biowaste and/or sludge. The questionnaire consisted of 102 items containing questions on perceived environmental nuisance. Odds ratios (ORs) and confidence intervals (CIs) were calculated adjusting for sex and age. The proportion of respondents perceiving odor varied by center and distance (< 1.5 km: 66-100%; 1.5 to < 3 km: 13-84%; 3 to < 5 km: 2-64%). The pooled OR for odor annoyance was 6.1 (95% CI 3.7-10) in the intermediate and 19 (95% CI 12-32) in the innermost zone compared with residents in the outermost zone. Intensity of odor characterized as very strong or fairly strong affected odor annoyance more than weekly or more frequently perceived odor. The high level of odor perception and annoyance in residents living near waste treatment centers draws attention to the need to prevent odor nuisance constricting emission peaks and frequent emissions. Because odors may affect fairly distant (even 1.5 to < 3 km) residential areas, planning of the locations of waste treatment operations is essential.

Fish consumption and polyunsaturated fatty acids in relation to psychological distress

BACKGROUND

It has been suggested that high fish consumption improves mental well-being. The aim of this study was to assess whether high fish consumption or omega-3 polyunsaturated fatty acid (PUFA) intake was associated with reduced self-reported psychological distress.

METHODS

We used three cross-sectional data sets, the nationwide Health 2000 Survey (n = 5840), the Fishermen Study on Finnish fishermen and their family members (n = 1282) and the Finntwin16 Study on young adults (n = 4986). Data were based on self-administered questionnaires, interviews, health examinations and blood samples. Psychological distress was measured using the 12-item and 21-item General Health Questionnaires (GHQs). Fish consumption was measured by a food frequency questionnaire (FFQ, g/day) and independent frequency questions (times/month). Dietary intake (g/day) and serum concentrations (% from fatty acids) of PUFAs were determined. Relationships were analysed using regression analysis.

RESULTS

Regardless of the measure, fish consumption and omega-3 PUFA dietary intake were not associated with distress in any of the data sets. In contrast to the hypothesis, high serum docosahexaenoic acid was associated with high distress in the Fisherman Study men. Some non-linear associations were detected between serum omega-3 PUFAs or fish consumption (times/month) and distress. In the Fishermen Study, the associations were modified by alcohol consumption, smoking and physical activity.

CONCLUSIONS

Our results do not support the hypothesis that fish consumption or omega-3 PUFA intake are associated with reduced psychological distress in the general population or in a population with high fish consumption.

Ozone and cause-specific cardiorespiratory morbidity and mortality

BACKGROUND

Health effects of ozone have been observed in numerous studies. However, analyses of more cause-specific morbidity or mortality outcomes have rarely been performed. A study was undertaken to determine the short-term associations of ozone with cause-specific cardiorespiratory mortality and morbidity by age groups.

METHODS

Daily levels of ozone were measured at a background measurement station in 1998-2004 in Helsinki, Finland. All analyses were a priori restricted to the warm season. Daily cause-specific cardiorespiratory mortality and hospital admissions were studied in elderly people (> or =65 years) and adults (15-64 years) and associations between ozone and asthma emergency room visits in children (<15 years) were analysed. All models were adjusted for PM(2.5) and Poisson regression was used for the analyses.

RESULTS

There was a positive association between ozone and admissions for asthma-chronic obstructive pulmonary disease (COPD) in elderly people (9.6%; 95% CI 2.0% to 17.8% at 0-day lag for 25 microg/m(3) increase in ozone). Consistent associations were also found between ozone and asthma emergency room visits in children (12.6%; 95% CI 0.8% to 25.1%, 0-day lag). There was a suggestion of an association between ozone and admissions for arrhythmia among elderly people (6.4%; 95% CI 0.63% to 12.5%, 1-day lag), which was slightly confounded by PM(2.5).

CONCLUSIONS

Positive associations were found for ambient ozone with asthma visits among children and with pooled asthma/COPD admissions among elderly people. The evidence for a positive association between ozone and cardiovascular health was weaker.

Effects of cold weather on mortality: results from 15 European cities within the PHEWE project

Weather-related health effects have attracted renewed interest because of the observed and predicted climate change. The authors studied the short-term effects of cold weather on mortality in 15 European cities. The effects of minimum apparent temperature on cause- and age-specific daily mortality were assessed for the cold season (October-March) by using data from 1990-2000. For city-specific analysis, the authors used Poisson regression and distributed lag models, controlling for potential confounders. Meta-regression models summarized the results and explored heterogeneity. A 1 degrees C decrease in temperature was associated with a 1.35% (95% confidence interval (CI): 1.16, 1.53) increase in the daily number of total natural deaths and a 1.72% (95% CI: 1.44, 2.01), 3.30% (95% CI: 2.61, 3.99), and 1.25% (95% CI: 0.77, 1.73) increase in cardiovascular, respiratory, and cerebrovascular deaths, respectively. The increase was greater for the older age groups. The cold effect was found to be greater in warmer (southern) cities and persisted up to 23 days, with no evidence of mortality displacement. Cold-related mortality is an important public health problem across Europe. It should not be underestimated by public health authorities because of the recent focus on heat-wave episodes.

Urban air pollution, and asthma and COPD hospital emergency room visits

BACKGROUND

There is little previous information of the effects of size fractioned particulate air pollution and source specific fine particles (PM(2.5); <2.5 microm) on asthma and chronic obstructive pulmonary disease (COPD) among children, adults and the elderly.

OBJECTIVES

To determine the effects of daily variation in levels of different particle size fractions and gaseous pollutants on asthma and COPD by age group.

METHODS

Levels of particulate air pollution, NO(2) and CO were measured from 1998 to 2004 at central outdoor monitoring sites in Helsinki, Finland. Associations between daily pollution levels and hospital emergency room visits were evaluated for asthma (ICD10: J45+J46) in children <15 years old, and for asthma and COPD (ICD10: J41+J44) in adults (15-64 years) and the elderly (>or=65 years).

RESULTS

Three to 5 day lagged increases in asthma visits were found among children in association with nucleation (<0.03 microm), Aitken (0.03-0.1 microm) and accumulation (0.1-0.29 microm) mode particles, gaseous pollutants and traffic related PM(2.5) (7.8% (95% CI 3.5 to 12.3) for 1.1 microg/m(3) increase in traffic related PM(2.5) at lag 4). Pooled asthma-COPD visits among the elderly were associated with lag 0 of PM(2.5), coarse particles, gaseous pollutants and long range transported and traffic related PM(2.5) (3.9% (95% CI 0.28 to 7.7) at lag 0). Only accumulation mode and coarse particles were associated with asthma and COPD among adults.

CONCLUSIONS

Among children, traffic related PM(2.5) had delayed effects, whereas among the elderly, several types of particles had effects that were more immediate. These findings suggest that the mechanisms of the respiratory effects of air pollution, and responsible pollutants, differ by age group.

Comparison of methods for editing of ectopic beats in measurements of short-term non-linear heart rate dynamics

Non-linear heart rate (HR) dynamics characterizes the fractal properties and complexity of the variations in HR. Ventricular and supraventricular ectopic beats might introduce a mathematical artefact to the analyses on sinus rhythm. We therefore evaluated the effects of different editing practices for ectopic beats such that 753 40-min ECG recordings were (i) not edited for the ectopic beats, or the ectopic beats were edited with (ii) an interpolation or with (iii) a deletion method before the analyses of non-linear HR dynamics. The non-linear HR dynamics analyses included detrended fluctuation analysis (DFA), approximate entropy, symbolic dynamics (SymDyn), fractal dimension and return map (RM). We found that the short-term scaling exponent (alpha1) of DFA, forbidden words of SymDyn and RM were sensitive measurements to the ectopic beats and there were strong correlations between these measurements and the number of ectopic beats. In addition, the unedited ectopic beats significantly lowered the stability of these measurements. However, the editing either with interpolation or deletion method corrected the measurements for the bias caused by the ectopic beats. On the contrary, the entropy measurements were not as sensitive to the ectopic beats. In conclusion, the ectopic beats affect the non-linear HR dynamics of sinus rhythm differently, causing a more marked bias in fractal than in complexity measurements of non-linear HR dynamics. This erroneous effect of ectopic beats can be corrected with a proper editing of these measurements. Therefore, there is an obvious need for standardized editing practices for ectopic beats before the analysis of non-linear HR dynamics.

Source-specific fine particles in urban air and respiratory function among adult asthmatics

Fine and ultrafine particles in ambient air are more consistently associated with severe adverse health effects than coarse particles. We assessed whether the effects of PM(2.5) on peak expiratory flow (PEF) and respiratory symptoms in asthma patients differ by the source or the chemical properties of particles. A panel of 57 adult asthmatics was followed for 181 days from November 1996 to April 1997 with 3 daily PEF measurements and diaries. Air quality, including elemental analyses of PM(2.5) filters every 2 days (n= 83), was monitored at a central site. Daily concentrations of PM(2.5) from different sources were estimated using principal component analysis and multiple linear regression. Associations of PM(2.5) from different sources with respiratory endpoints were examined using a generalized least squares autoregressive model after adjustment for covariates. PM(2.5) attributable to local combustion was consistently negatively associated with all measurements of PEF. One interquartile increase (1.3 microg/m(3)) in 5-day average concentrations of PM(2.5) attributable to local combustion was associated with an average 1.14 L/min decline in evening PEF (95% CI: -1.95 to -0.33 L/min). We also observed that PM(2.5) attributable to long-range transport was positively, and soil-derived PM(2.5) negatively, associated with PEF. No consistent associations were observed between source-specific PM(2.5) and respiratory symptoms or between individual chemical elements and any respiratory endpoints. Our results suggest that the negative effects of PM(2.5) on PEF in adult asthmatics are mainly mediated by particles related to local combustion sources.

Associations of Fine and Ultrafine Particulate Air Pollution With Stroke Mortality in an Area of Low Air Pollution Levels

Background and Purpose— Daily variation in outdoor concentrations of inhalable particles (PM 10 <10 μm in diameter) has been associated with fatal and nonfatal stroke. Toxicological and epidemiological studies suggest that smaller, combustion-related particles are especially harmful. We therefore evaluated the effects of several particle measures including, for the first time to our knowledge, ultrafine particles (<0.1 μm) on stroke.

Methods— Levels of particulate and gaseous air pollution were measured in 1998 to 2004 at central outdoor monitoring sites in Helsinki. Associations between daily levels of air pollutants and deaths caused by stroke among persons aged 65 years or older were evaluated in warm and cold seasons using Poisson regression.

Results— There was a total of 1304 and 1961 deaths from stroke in warm and cold seasons, respectively. During the warm season, there were positive associations of stroke mortality with current- and previous-day levels of fine particles (<2.5 μm, PM 2.5 ) (6.9%; 95% CI, 0.8% to 13.8%; and 7.4%; 95% CI, 1.3% to 13.8% for an interquartile increase in PM 2.5 ) and previous-day levels of ultrafine particles (8.5%; 95% CI, −1.2% to 19.1%) and carbon monoxide (8.3; 95% CI, 0.6 to 16.6). Associations for fine particles were mostly independent of other pollutants. There were no associations in the cold season.

Conclusions— Our results suggest that especially PM 2.5 , but also ultrafine particles and carbon monoxide, are associated with increased risk of fatal stroke, but only during the warm season. The effect of season might be attributable to seasonal differences in exposure or air pollution mixture.

Associations of traffic related air pollutants with hospitalisation for first acute myocardial infarction: the HEAPSS study

BACKGROUND

Acute myocardial infarction (AMI) is the leading cause of death attributed to cardiovascular diseases. An association between traffic related air pollution and AMI has been suggested, but the evidence is still limited.

OBJECTIVES

To evaluate in a multicentre study association between hospitalisation for first AMI and daily levels of traffic related air pollution.

METHODS

The authors collected data on first AMI hospitalisations in five European cities. AMI registers were available in Augsburg and Barcelona; hospital discharge registers (HDRs) were used in Helsinki, Rome and Stockholm. NO2, CO, PM10 (particles <10 microm), and O3 were measured at central monitoring sites. Particle number concentration (PNC), a proxy for ultrafine particles (<0.1 microm), was measured for a year in each centre, and then modelled retrospectively for the whole study period. Generalised additive models were used for statistical analyses. Age and 28 day fatality and season were considered as potential effect modifiers in the three HDR centres.

RESULTS

Nearly 27,000 cases of first AMI were recorded. There was a suggestion of an association of the same day CO and PNC levels with AMI: RR = 1.005 (95% CI 1.000 to 1.010) per 0.2 mg/m3 and RR = 1.005 (95% CI 0.996 to 1.015) per 10000 particles/cm3, respectively. However, associations were only observed in the three cities with HDR, where power for city-specific analyses was higher. The authors observed in these cities the most consistent associations among fatal cases aged <75 years: RR at 1 day lag for CO = 1.021 (95% CI 1.000 to 1.048) per 0.2 mg/m3, for PNC = 1.058 (95% CI 1.012 to 1.107) per 10000 particles/cm3, and for NO2 = 1.032 (95% CI 0.998 to 1.066) per 8 microg/m3. Effects of air pollution were more pronounced during the warm than the cold season.

CONCLUSIONS

The authors found support for the hypothesis that exposure to traffic related air pollution increases the risk of AMI. Most consistent associations were observed among fatal cases aged <75 years and in the warm season.

Comparison of different methods in analyzing short-term air pollution effects in a cohort study of susceptible individuals

BACKGROUND

Short-term fluctuations of ambient air pollution have been associated with exacerbation of cardiovascular disease. A multi-city study was designed to assess the probability of recurrent hospitalization in a cohort of incident myocardial infarction survivors in five European cities. The objective of this paper is to discuss the methods for analyzing short-term health effects in a cohort study based on a case-series.

METHODS

Three methods were considered for the analyses of the cohort data: Poisson regression approach, case-crossover analyses and extended Cox regression analyses. The major challenge of these analyses is to appropriately consider changes within the cohort over time due to changes in the underlying risk following a myocardial infarction, slow time trends in risk factors within the population, dynamic cohort size and seasonal variation.

RESULTS

Poisson regression analyses, case-crossover analyses and Extended Cox regression analyses gave similar results. Application of smoothing methods showed the capability to adequately model the complex time trends.

CONCLUSION

From a practical point of view, Poisson regression analyses are less time-consuming, and therefore might be used for confounder selection and most of the analyses. However, replication of the results with Cox models is desirable to assure that the results are independent of the analytical approach used. In addition, extended Cox regression analyses would allow a joint estimation of long-term and short-term health effects of time-varying exposures.

Effects of ultrafine and fine particulate and gaseous air pollution on cardiac autonomic control in subjects with coronary artery disease: the ULTRA study

Previous studies have shown an association between elevated concentrations of particulate air pollution and cardiovascular morbidity and mortality. Therefore, the association between daily variation of ultrafine and fine particulate air pollution and cardiac autonomic control measured as heart rate variability (HRV) was studied in a large multicenter study in Amsterdam, the Netherlands, Erfurt, Germany, and Helsinki, Finland. Elderly subjects (n=37 in Amsterdam, n=47 in both Erfurt and Helsinki) with stable coronary artery disease were followed for 6 months with biweekly clinical visits. During the visits, ambulatory electrocardiogram was recorded during a standardized protocol including a 5-min period of paced breathing. Time and frequency domain analyses of HRV were performed. A statistical model was built for each center separately. The mean 24-h particle number concentration (NC) (1,000/cm(3)) of ultrafine particles (diameter 0.01-0.1 microm) was 17.3 in Amsterdam, 21.1 in Erfurt, and 17.0 in Helsinki. The corresponding values for PM2.5 were 20.0, 23.1, and 12.7 microg/m(3). During paced breathing, ultrafine particles, NO(2), and CO were at lags of 0-2 days consistently and significantly associated with decreased low-to-high frequency ratio (LF/HF), a measure of sympathovagal balance. In a pooled analysis across the centers, LF/HF decreased by 13.5% (95% confidence interval: -20.1%, -7.0%) for each 10,000/cm(3) increase in the NC of ultrafine particles (2-day lag). PM2.5 was associated with reduced HF and increased LF/HF in Helsinki, whereas the opposite was true in Erfurt, and in Amsterdam, there were no clear associations between PM2.5 and HRV. The results suggest that the cardiovascular effects of ambient ultrafine and PM2.5 can differ from each other and that their effect may be modified by the characteristics of the exposed subjects and the sources of PM2.5.

Dust sampling methods for endotoxin - an essential, but underestimated issue

Exposure to farming environment in early life has been associated with lower risk for allergic diseases possibly caused by increased exposure to endotoxin. The aims of this study were to compare the reproducibility of different sampling methods for endotoxin, and to determine whether environmental characteristics have different effect on endotoxin levels of different sample types. The reproducibility of sampling methods (bed dust, floor dust, vacuum cleaner dust bag dust, settled dust and air samples) was studied with repeated sampling (five visits during 1 year) in five farming and five urban homes. To examine determinants of endotoxin for different types of dust sample, sampling was conducted once in 12 farming and 17 urban homes. Endotoxin was analyzed using Limulus Amebocyte Lysate assay. Bed dust samples had the best reproducibility (intraclass correlation, ICC=66%), but the difference between farming and non-farming homes was not clear with this sample type. The reproducibility of floor (ICC=52%) and settled dust (ICC=51%) was moderate. With these sample types the difference between farming and non-farming homes was clear. Settled dust had some seasonal variation. Based on this study, the best compromise for sampling for endotoxin appears to be floor dust sample followed by bed and settled dust samples. Practical Implications Endotoxins have been widely measured, even though the validity of different sample types to reflect the endotoxin exposure level of an indoor environment is poorly known. This study shows that bed dust samples have the best reproducibility, but they do not reflect the differences in exposure due to environmental factors such as farming. Floor dust samples with moderate reproducibility may be the best choice for sampling of endotoxin in large field studies.

Stability over time of short-term heart rate variability

Heart rate variability (HRV) is a widely used method to assess cardiac autonomic control. However, the reproducibility of especially short-term HRV has not been properly evaluated. Therefore, we assessed the stability of short-term HRV over a three to four month period. We had seven consecutive electrocardiographic (ECG) recordings from 89 subjects with stable coronary artery disease obtained during a large multicenter study. The HRV assessments were performed from these 40-minute ECG-recordings simulating normal daily activities, i. e., recordings consisting of 5 to 10 minute periods of rest, paced breathing, standing, submaximal exercise and recovery. Both time and frequency domain HRV analyses were conducted from the whole 40-minute recordings and from the 5-minute periods of rest and paced breathing. The coefficient of variation (CV) varied between 5.1-16.7% for the 40-minute and 6.0-37.1% for the 5-minute time domain and 4.4-11.0 % for the 40-minute and 7.2-16.5 % for the 5-minute frequency domain measurements. The mean of the RR intervals and the total power showed the highest stability over time. The most unstable measure was the standard deviation of all NN intervals (SDNN). In conclusion, most short-term HRV measures were highly stable over time indicating low physiological variation. However, the SDNN showed large variability in consecutive recordings.