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Cardiovascular diseases and air pollution in Novi Sad, Serbia

100%

Jevtić M., Dragić N., Bijelović S., Popović M.

International Journal of Occupational Medicine and Environmental Health

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2014

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vol. 27

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issue 2

153-164

EN

Objectives: A large body of evidence has documented that air pollutants have adverse effect on human health as well as on the environment. The aim of this study was to determine whether there was an association between outdoor concentrations of sulfur dioxide (SO₂) and nitrogen dioxide (NO₂) and a daily number of hospital admissions due to cardiovascular diseases (CVD) in Novi Sad, Serbia among patients aged above 18. Material and Methods: The investigation was carried out during over a 3-year period (from January 1, 2007 to December 31, 2009) in the area of Novi Sad. The number (N = 10 469) of daily CVD (ICD-10: I00-I99) hospital admissions was collected according to patients' addresses. Daily mean levels of NO₂ and SO₂, measured in the ambient air of Novi Sad via a network of fixed samplers, have been used to put forward outdoor air pollution. Associations between air pollutants and hospital admissions were firstly analyzed by the use of the linear regression in a single polluted model, and then trough a single and multi-polluted adjusted generalized linear Poisson model. Results: The single polluted model (without confounding factors) indicated that there was a linear increase in the number of hospital admissions due to CVD in relation to the linear increase in concentrations of SO₂ (p = 0.015; 95% confidence interval (95% CI): 0.144-1.329, R² = 0.005) and NO₂ (p = 0.007; 95% CI: 0.214-1.361, R² = 0.007). However, the single and multi-polluted adjusted models revealed that only NO₂ was associated with the CVD (p = 0.016, relative risk (RR) = 1.049, 95% CI: 1.009-1.091 and p = 0.022, RR = 1.047, 95% CI: 1.007-1.089, respectively). Conclusions: This study shows a significant positive association between hospital admissions due to CVD and outdoor NO₂ concentrations in the area of Novi Sad, Serbia.

2

An approach to represent a combined exposure to air pollution

86%

Szyszkowicz M.

International Journal of Occupational Medicine and Environmental Health

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2015

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vol. 28

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issue 5

823-830

EN

Objectives The objective of this study was to present a technique for estimating the effect of ambient air pollution mix on health outcomes. Material and Methods We created a technique of indexing air pollution mix as a cause of the increased odds of health problems. As an illustrative example, we analyzed the impact of pollution on the frequency of emergency department (ED) visits due to colitis among young patients (age < 15 years, N = 11 110). Our technique involves 2 steps. First, we considered 6 ambient air pollutants (carbon monoxide, nitrogen dioxide, sulphur dioxide, ozone, and 2 measures of particulate matter) treating each pollutant as a single exposure. Odds ratios (ORs) for ED visits associated with a standard increase (interquartile range – IQR) in the pollutants levels were calculated using the case-crossover technique. The ORs and their 95% confidence intervals (95% CIs) were also found for lagged exposures (for lags 1–9 days). Second, we defined a Health Air Study Index (HASI) to represent the combined impact of the 6 air pollutants. Results We obtained positive and statistically significant results for individual air pollutants and among them the following estimations: OR = 1.06 (95% CI: 1.02–1.1, NO₂ lag 3, IQR = 12.8 ppb), OR = 1.04 (95% CI: 1.01–1.07, SO₂ lag 4, IQR = 2.3 ppb), OR = 1.04 (95% CI: 1–1.06, PM lag 3, IQR = 6.2 μg/m³). Among the re-calculated ORs with the HASI values as an exposure, the highest estimated value was OR = 1.37 (95% CI: 1.12–1.68, for 1 unit of the HASI, lag 3). Conclusions The proposed index (HASI) allows to confirm the pattern of associations for lags obtained for individual air pollutants. In the presented example the used index (HASI) indicates the strongest relation with the exposure lagged by 3 days.

3

The use of chained two-point clusters for the examination of associations of air pollution with health conditions

86%

Szyszkowicz M., Burr W. S.

International Journal of Occupational Medicine and Environmental Health

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2016

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vol. 29

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issue 4

613-622

EN

Objectives There are a few accepted and intensively applied statistical methods used to study associations of ambient air pollution with health conditions. Among the most popular methods applied to assess short term air health effects are case-crossover (using events) and time-series methodologies (using counts). A few other techniques for studying counts of events have been proposed, including the Generalized Linear Mixed Models (GLMM). One suggested GLMM technique uses cluster structures based on natural embedded hierarchies: days are nested in the days of a week (dow), which, in turn, are nested in months and months in years (< dow, month, years >). Material and Methods In this study the authors considered clusters with hierarchical structures in a form of < dow, 14-days, year >, where the 14-days hierarchy determines 7 clusters composed of 2 days (the same days) of a week (2 Mondays, 2 Tuesdays, etc.), in 1 year. In this work the authors proposed hierarchical chained clusters in which 2 days of a week are grouped as follows: (first, second), (second, third), (third, fourth) and so on. Such an approach allows determination of an additional series of the slopes on the clusters (second, third), (fourth, fifth), etc., i.e., estimation of the coefficients for other configurations of air pollutant levels. The authors considered a series of 2 point chained clusters covering a year. In such a construction each cluster has one common data point (day) with another one. Results The authors estimated coefficients (slopes) related to the ambient ozone exposure (mortality) and to 3 selected air pollutants (particulate matter, nitrogen dioxide and ozone) combined into index and considered as health risk exposure (emergency department (ED) visits). The generated results were compared to the estimations obtained from the time-series method and the time-stratified case-crossover method applied to the same data. Conclusions The proposed statistical method, based on the chained hierarchical clusters (< dow, 14-days, year >), generated results with shorter confidence intervals than the other methods.

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3 International Journal of Occupational Medicine and Environmental Health

2 Szyszkowicz M.

1 Bijelović S.

1 Burr W. S.

1 Dragić N.

1 Jevtić M.

1 Popović M.

1 2016

1 2015

1 2014

Cardiovascular diseases and air pollution in Novi Sad, Serbia

An approach to represent a combined exposure to air pollution

The use of chained two-point clusters for the examination of associations of air pollution with health conditions