Zdrav Var 2007; 46: 47-54 47 AIR POLLUTION AND RESPIRATORY SYMPTOMS IN THE FEMALE POPULATION ONESNAŽENOST ZRAKA IN SIMPTOMI V DIHALIH PRI ŽENSKI POPULACIJI Aleksandra Stankovič1, Dragana Nikič1, Maja Nikolič1, Dragan Bogdanovič1, Ljiljana Stošič1, Suzana Milutinovič1, Olivera Radulovič1 Prispelo: 6. 3. 2006 - Sprejeto: 15. 3. 2007 Original scientific article UDC 616.2 Abstract The objective of the study vvas to examine the relationship betvveen the exposure to outdoor and indoor air pollut-ants and respiraton/ health of vvomen. Outdoor concentrations of sulphur dioxide and black smoke vvere studied during the period 2000 -2004, in residential and suburban areas of the city of Niš, Serbia. The study population comprised 653 vvomen, aged 33.87± 3.0 years. Data on respiraton/symptoms, diseases and exposure to indoor air pollutants (passive smoking and smoke of combustion products) vvere collected using a questionnaire. Women living in the residential area shovved a significantly higher prevalence of ali respiratory symptoms. Also, a positive correlation vvas found betvveen cough, congestion and bronchitis, and exposure to passive smoking. There vvas no statistical difference in respiraton/ symptoms betvveen vvomen exposed to combustion products compared to unex-posed vvomen. Key words: air pollution, respiratory symptoms, respiratory diseases, vvomen Izvirni znanstveni članek UDK 616.2 Izvleček V raziskavi so želeli ugotoviti povezanost med onesnaženostjo zunanjega in notranjega zraka in boleznimi dihal pri ženskah. V obdobju od 2000 do 2004 so merili koncentracije žveplovega dioksida in črnega dima v zraku, in sicer v stanovanjskem in v predmestnem predelu Niša v Srbiji. V študijo je bilo zajetih 653 žensk, starih 33.87± 3.0 let. Podatke o simptomih in boleznih dihal ter o izpostavljenosti onesnaževalcem v zunanjem in notranjem zraku (tobačni dim, pasivno kajenje in dim iz gorljivih materialov) so zbirali s pomočjo vprašalnika. Pri ženskah v stanovanjski soseski so ugotovili statistično značilno večjo pogostnost simptomov v dihalih. Našli so tudi pozitivno korelacijo med pojavi kašlja, kongestije in bronhitisa in pasivnim kajenjem. Pri ženskah, izpostavljenih dimu gorljivih materialov, niso ugotovili statistično značilno več dihalnih težav kot pri ženskah, ki temu dimu niso izpostavljene. Ključne besede: onesnaženost zraka, simptomi in bolezni dihal, ženska populacija 1Public Health Institute, University of Ni{, School of Medicine, Ni{, Serbia and Montenegro Correspondence to: e-mail: aleksandra@exe-mail.net 48 Zdrav Var 2007; 46 Introduction Air pollution has become a major concern vvorld-wide because of its hazardous effects on human health (1). Traffic, industry and heating are the major sources of air pollution in towns. Among many natural and anthropogenic sources of air pollution, the combustion of fossil fuels is a major contributor in urban and industrial societies. People living in urban areas are permanently exposed to some level of pollutants. The respiratory system is the primary target of air pollutants, which most frequently enter human or-ganism through inhalation. The level of their pen-etration in the lungs and their remaining in the plače of potential damage depend on their physical and chemical characteristics (2). VVater-soluble pollutants are completely extracted in the upper respira-tory tract in contrast to poorly soluble pollutants which enter the respiratory ways and alveoli to a lesser extent. The mechanisms by which air pollutants damage the lungs are not yet completely clear, and could be roughly divided into acute irritation and inflam-mation, chronic inflammation with fibrous response to some agents, challenge of immune response and cancer genesis (3,4). Health consequences of air pollution are either acute or chronic, depending on the pollutant con-centration, meteorological conditions, duration of exposure to pollutants (long-term and short-term) and health condition. Studies conducted in a wide range of cities with different levels of air pollution have reported increase in the rate of mortality and morbidity from different causes and in various age groups (5,6). Air pollu-tion-related diseases are the most important cause of respiratory morbidity and mortality in adults. There are also indications that health effects of air pollution are stronger in sensitive population groups, such as children, women and persons with chronic diseases (7). Sources of indoor air pollution with constant or pe-riodical emission of pollutants can be found in any home. They differ from outdoor pollutants in their concentration, which is sometimes significantly higher. VVhether the concentration of the emitted indoor pollutants increases or decreases depends on the type of the pollutant, its character, store of its source, mechanism of spontaneous evolution, and fre-quency of indoor ventilation, which is of a great importance if the emitted contaminating indoor substance is not reactive. The most common indoor pollutants include: sulphur dioxide, various solvents, tobacco smoke, carbon monoxide, radon, nitric ox-ides, formaldehyde and asbestos. In addition to these chemical pollutants, biological contaminants, such as mites, insects, spores of fungi and ani-mals' allergens, are also found indoors (8). People react differently to their exposure to indoor air pollutants. Their response depends on three important factors: age, health condition and sensitiv-ity. Respiratory tract is the first to suffer if some-one is exposed to indoor pollutants, which leads to the development of respiratory symptoms and diseases (9,10). This study was undertaken to assess the preva-lence of respiratory symptoms and diseases in women exposed to significantly different quantities of outdoor air pollutants. The main aim of the study was to determine the role of indoor air pollutants in the development of respiratory symptoms and conditions, which are not caused by exposure to outdoor air pollution. Methods Outdoor air pollutants were measured at two mea-suring sites in the city of Niš, one in the residential and another in the suburban area. The two sites were selected for the study because they differed significantly in concentrations of the pollutants de-termined by the Institute of Public Health. Concentrations of the outdoor air pollutants sulphur dioxide and black smoke were measured 24 hours a day, during the period 2000 - 2004. Sampling was carried out by a specially trained personnel. Labo-ratory tests for sulphur dioxide and black smoke were done in accordance with the Regulations of Guideline Values of Emission (The Official Bulletin of the Republic of Serbia 54/92) (11). Ambient levels of black smoke were measured by the reflectance of a sampled filter. The sampling was preformed using a pump operating at a flow rate of 1 L/min through VVhattman type N°1 paper filters. Air concentration of sulphur dioxide was determined simultaneously with that of black smoke. A measured volume of air was bubbled through the solu-tion of potassium mercury tetrachloride. Sulphur dioxide present in the air stream reacted with the solution to form stable monochlorosulfo- Stankovič A. et al. Air pollution and respiratory symptoms in the female population 49 natomercurate.This complex was brought into re-action with acid-bleached pararosaniline dye and formaldehyde, yielding intensely coloured pararosaniline methyl sulphuric acid. Optical density was determined spectrophotometrically at 548 nm, and was directly related to the collected amount of sul-phur dioxide. The total volume of air sample was determined from the flow rate and sampling tirne. The concentration of sulphur dioxide in the ambient air was computed and expressed in |jg/m3; the lower limit of detection was 1.7 |jg/m3. This study included 653 vvomen, aged 33.87± 3.0, living in two areas with different levels of common outdoor air pollutants sulphur dioxide and black smoke. One group (356) lived in a residential area, and another (197) in a suburban area. VVomen of both groups were not smokers and were not profes-sionally exposed to air pollution. They had lived for at least five years at those locations, at a distance of one km from the measuring site. A standard WHO questionnaire was used for the first part of the study (12). The questionnaires were com-pleted by physicians during the intervievv with the vvomen. The survey vvas conducted in May 2005. The questionnaire included questions about the prevalence of respiratory symptoms (cough related/ unrelated to cold, congestion and/or phlegm- related/ unrelated to cold, runny noše lasting longer than three mounts, vvheezing and respiratory diseases (sinusitis, bronchitis, asthma, pneumonia), vvhich had been diagnosed by physicians over the previ-ous 12 months. Exposure to indoor air pollution vvas assessed us-ing the original questionnaire. Special emphasis vvas placed on the women's exposure to passive smok-ing and to smoke of combustion products. The ques-tions concerning the exposure to smoke of combustion products vvere as follovvs: "Do you have central heating system in your home?", "Do you heat your living room?", "VVhich kind of heating material do you use?". Exposure to passive smok-ing vvas assessed on the basis of ansvvers to the follovving questions: "Does anyone smoke in the house?" and "Hovv many smokers live in the house?". The collected data vvere processed using a soft-vvare system. Data obtained through the intervievv vvere analysed using the Epiinfo 6.0 and Microsoft Excel statistical programmes. Statistically signifi-cant levels of the measured sulphur dioxide and black smoke vvere determined using the Studenfs t-test, and differences at p<0.01 vvere considered statistically significant. Statistical significance of the difference vvas established vvith the Pearson's chi-squared test. The odds ratio and a 95%-confi-dence interval vvere calculated to evaluate the as-sociation of respiratory symptoms and diseases in vvomen vvith environmental variables. Results Outdoor air pollutants, sulphur dioxide and black smoke, vvere monitored at tvvo measuring sites, one in the residential and another in the suburban area. The average annual concentrations of sulphur diox-ide and black smoke at measuring locations did not exceed Serbia's maximum allovved concentrations for the corresponding year (50 ?g/m3 ). Also, the average levels of the pollutants remained belovv the current WHO guidelines. Hovvever, the values of both pollutants vvere significantly lovver in the suburban area than in the residential area . The t-test statistics shovved significantly higher average annual concentrations of sulphur dioxide and black smoke at the residential area measuring lo-cation, as compared to values measured in the suburban area. Differences betvveen average annual values vvere statistically significant for both pollutants (p <0. 01 ) (Tables 1 and 2). Table 3 indicates the rate of respiratory symptoms and diseases in the vvomen studied. VVomen from the residential area had a higher prevalence of ali respiratory symptoms than vvomen living in the suburban area (10.35 to 89.54, 8.09 to 75.14, respec-tively). Bronchitis vvas the only respiratory disease vvith a statistically higher prevalence among vvomen from the residential area. No connection vvas found betvveen high outdoor pollutant concentrations and oc-currence of sinus problems, pneumonia and asthma. Our study shovved no statistically significant rela-tionship betvveen exposure to smoke of combustion products and respiratory morbidity. Respiratory symptoms, especially cough and congestion and/ or phlegm related to cold, vvere more common among vvomen exposed to passive smoking, (Table 4). Bronchitis vvas significantly more frequently diagnosed in vvomen vvhose husbands smoked at home. 50 Zdrav Var 2007; 46 Table 1. Air concentrations of sulphur dioxide (ug/m3) in two areas studied. Tabela 1. Koncentracije žveplovega dioksida (ug/m3) v zraku dveh preučevanih območij. Year / Leto No.of measurements / [t. meritev Residential area / Stanovanjska soseska Suburban area / Primestno obmo~je tp Mean + SD Range Mean + SD Range 2000 302 12+17.15 0 - 89 7+12.23 0 - 75 9.962 P<0.01* 2001 232 10±12.09 0 -54 8±6.75 0-25 3.954 P<0.01* 2002 325 15±8.79 0 -70 2±4.42 0-30 14.690 P<0.01* 2003 336 23±8.63 0 -47 4±5.33 0-34 20.208 P<0.01* 2004 337 22±18.88 0 -113 6±6.29 0-50 16.576 P<0.01* *statistically significant differences / statisti~no zna~ilne razlike Table 2. Air concentrations of black smoke (ug/m3) in two areas studied. Tabela 2. Koncentracije črnega dima (ug/m3)v zraku dveh preučevanih območij. Year / Leto No. of measurements / [t.meritev Residential area / Stanovanjski predel Suburban area / Primestno obmo~je t p Mean ± SD Range Mean + SD Range 2000 302 37+26.58 0 -224 1+4.58 0 -73 15.072 p<0.01* 2001 232 41+33.06 0 -206 2+3.82 0 -15 15.837 p<0.01* 2002 325 39+39.78 0 -249 1+1.60 0 -11 17.947 p<0.01* 2003 336 33+30.07 4 -167 1+2.09 0 -18 22.241 p<0.01* 2004 337 34+30.54 0 -289 1+11,68 0 -14 18.526 p<0.01* *statistically significant differences / statisti~no zna~ilne razlike Stankovič A. et al. Air pollution and respiratory symptoms in the female population 51 Table 3. Prevalence of respiratory symptoms and diseases and exposure to outdoor air pollution. Tabela 3. Pogostnost simptomov in bolezni v dihalih in izpostavljenost onesna`enemu zunanjemu zraku. Respiratory symptoms and diseases / Respiratorni simptomi in obolenja Prevalence / (%) Pogostnost 1 Odds ratio / Razmerje obetov (95%CI) Residential area / Stanovanjski predel Suburban area / Primestno obmo~je Cough related to cold / Ka{elj zaradi prehlada 89.54 75.14 6.64* 1.84 (1.21-3.13) Cough unrelated to colds / Ka{elj, ki ni povezan s prehladom 45.83 26.34 14.96* 4.49 (1.89-10.96) Congestion and/ or phlegm related to cold / Kongestija in/ali sluz zaradi prehlada 27.69 8.09 10.46* 3.03 (1.62-10.08) Congestion and/ or phlegm unrelated to cold / Kongestija in/ali sluz nepovezana s prehladom 28.80 16.21 12.30* 3.01 (1.53-5.97) Runny noše for more than 3 months / Nahod več kot 3 mesece 22.11 15.62 6.80* 2.43 (1.17-5.08) VVheezing / Hropenje 10.35 8.36 7.16* 2.58 (1.22-6.89) Sinus problems / Te`ave s sinusi 48.49 42.67 1.00 0.02 (0.22-1.74) Bronchitis / Bronhitis 47.63 38.57 9.26* 3.39 (1.40-8.90) Pneumonia / Pljučnica 15.83 14.80 0.26 1.16 (0.63-2.13) Asthma / Astma 8.94 7.43 3.28 0.17 (0.01-1.62) * p < 0.01 52 Zdrav Var 2007; 46 Table 4. Exposure to indoor air pollution and the occurrence of respiratory symptoms and diseases. Tabela 4. Izpostavljenost onesna`enemu notranjemu zraku in pojav simptomov in bolezni v dihalih. Respiratory symptoms and diseases / Respiratorni simptomi in obolenja Smoke of combustion products / Dim gorljivih materialov Passive smoking / Pasivno kajenje Exposed/ Izpostavlj enost n=250) Not Exposed/ Ni izpostavlj enosti (n=403) X Odds ratio / Razmerje obetov (95%CI) Exposed/ Izpostavlje nost (n=526) No exposed / Ni izpostavlje nosti (n=127) X Odds ratio / Razmerje obetov (95%CI) Cough related to cold / Ka{elj zaradi prehlada 19 (7.6%) 10 (2.5%) 3.01 2.01 (0.85 -4.84) 23 (4.4%) 6 (4.7%) 6.71* 1.48 (1.09 -2.01) Cough unrelated to cold / Ka{elj nepovezan s prehladom 17 (6.8%) 15 (3.7%) 1.65 1.18 (0.91 -1.53) 18 (3.4%) 16 (12.6%) 0.01 1.02 (0.78 -1.33) Congestion and/ or phlegm related to cold / Kongestija in/ali sluz zaradi prehlada 31 (12.4%) 25 (6.2%) 3.30 2.00 (0.89 -4.60) 38 (7.2%) 18 (14.1%) 6.44* 1.45 (1.08 -1.95) Congestion and/ or phlegm unrelated to cold / Kongestija in/ali sluz nepovezana s prehladom 15 (6.0%) 2 (0.5%) 0.59 1.15 (0.79 -1.68) 8 (1,5%) 9 (7,1%) 0.32 1.1 (0.78 -1.56) Runny noše for more than 3 months / Nahod več kot 3 mesece 29 (11.6%) 18 (4.5%) 1.85 1.27 (0.89 -1.81) 25 (4.7%) 22 (17.3%) 0.3 1.26 (0.53 -3.08) VVheezing / Hropenje 20 (8.0%) 11 (2.7%) 3.47 1.34 (0.97 -1.84) 15 (2.8%) 16 (12.6%) 0.79 1.2 (0.79 -1.83) Sinus problems / Te `ave s sinusi 24 (9.6%) 10 (2.5%) 0.54 1.14 (0.86 -1.68) 17 (3.2%) 17 (13.4%) 3.2 1.43 (0.95 -2.15) Bronchitis / Bronhitis 12 (4.8%) 9 (2.2%) 3.06 2.02 (0.85 -4.84) 17 (3.2%) 4 (3.1%) 11.89* 1.66 (1.23 -2.23) Pneumonia/ Pljučnica 9 (3.6%) 5 (1.2%) 1.84 1.22 (0.79 -1.81) 8 (1.5%) 6 (4.7%) 0.9 1.18 (0.83 -1.67) Asthma / Astma 6 (2.4%) 5 (1,2%) 0.05 0.91 (0.39 - 2.21 7 (1.3%) 4 (3.1%) 3.74 1.35 (0.98 -1.84) * p<0.05 Stankovič A. et al. Air pollution and respiratory symptoms in the female population 53 Discussion The respiratory system, which is most exposed to negative influence of air pollutants, has various de-fensive mechanisms which preverit or alleviate their harmful effects. The most important defensive mechanisms of the respiratorv tract are cleaning and filtrating air by upper bronchial tubes, bronchial secretion of immunoglobin, Ivsosomes, sneezing and coughing reflexes and antioxidants in the mucus covering the lung's surface. Acute exposure of people to high concentrations of pollutants in the air has been investigated in previ-ous studies (13,14). It was established that acute exposure to air pollution can increase the incidence of respiratory symptoms and diseases. There is less information about chronic effects of lower concentrations of pollutants (15). It is assumed that chronical exposure can be associated with respira-tory symptoms and lung function disorders (16). The concentration of sulphur dioxide and soot dur-ing the study did not exceed the legally allovved lev-els and the WHO reference values. The group of women exposed to low concentrations of sulphur dioxide had a statistically significant prevalence of some respiratory symptoms and diseases. Studies done in Svvitzerland (17) confirmed this as-sertion and shovved that particle concentrations of 10 - 53 ?g/m3 , which is considerably below the allovved limits, cause respiratory symptoms and re-duce respiratory function. Forsberg and associates (18) confirmed a high risk for respiratory symptoms, such as cough, irritation of throat and noše, in indi-viduals exposed to and average annual concentrations of sulphur dioxide of 2-16?g/m3. Researchers in Helsinki established that an increase of sulphur dioxide levels exceeding 21?g/m3 increases the rate of respiratory infections by 15 % (19). Air pollution and the resulting chronic health prob-lems are not related to the quality of outdoor air only, since human health is influenced by the qual-ity of indoor air, too. Our study of the impact of indoor air pollution on health and onset of respiratory symptoms and diseases vvas focused on tvvo most important factors of indoor air pollution- heating and exposure to pas-sive smoking. The results shovved that exposure to smoke released by vvool and coal combustion is not responsible for the onset of respiratory symptoms and diseases. Most (but not ali) studies done vvorldvvide confirmed the connection betvveen exposure to smoke from fuel stores and respiratory morbidity. Holsein and associates (20) found no relationship betvveen the form of heating and respiratory symptoms. Research conducted in the USA (21) revealed no positive cor-relation betvveen the exposure to smoke of fuel stores and the occurrence of respiratory symptoms, asthma and allergic reactions. Other authors came to a similar conclusion (22, 23, 24). Conclusion Air pollution monitoring is very important for assess-ing the level of population exposure. This study shovved a correlation betvveen long-term exposure to lovv concentrations of outdoor air pollutants and the prevalence of respiratory morbidity in vvomen, vvhich stresses the need for follovving the example set by other countries, and to introduce stricter Immission Marginal Values of air pollutants in this country. Exposure to passive smoking seems to be a significant etiological factor in respiratory morbidity. A clear effect of exposure to common outdoor air pollutants during the life has not been established. References 1. Health Effects Institute. National morbiditv, mortalitv and air pollution studv. HEI Report 94, Part 2, 2000. 2. Jedrychowski W, Maugeri U. Variabilitv of respiratorv svstem reactions to air pollution. Pneumonol Alergol Po 1996; 64: 267-75. 3. Brunekreef B, Dockerv DW, Krzyzanowski M. 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