4. HEALTH CONSEQUENCES AND RISKS RELATED TO AIR POLLUTION

4.1 Organization of monitoring activities

Subsystem I is intended for the monitoring of selected indicators of population health and indoor/outdoor air quality. Information on population health status is obtained from general practitioners and paediatricians in out-patient facilities. Information on ambient air pollutant concentrations is obtained from the network of manual and automated units operated by the public health institutes in the cities monitored as well as from selected measuring facilities administrated by the Czech Hydrometeorological Institute, the location of which meets the requirements of the Monitoring System. Indoor air quality has been monitored within Subsystem I in cooperation with selected public health institutes.

4.2 Incidence of treated acute respiratory diseases

4.2.1 Results 2004

Acute respiratory diseases (ARD) account for the highest percentage of morbidity in children (peaking in pre-school children), and therefore the ARD incidence is used as an important indicator of population health. Incidence of ARD is influenced by air pollution, epidemiological situation, climatic conditions, individual characteristics and by physician’s subjective evaluation. The information source are medical records on the first treatment given to patients presenting with acute respiratory disease. The basic outputs are absolute numbers of new cases of selected diagnoses in the population monitored and their incidence rates per 1,000 population of different age groups. The data are entered in the system database of treated ARD acronymed MONARO. The database is an integrated system that allows continual collection, processing and evaluation of the data on ARD morbidity obtained from general practitioners and paediatricians. The central database is being regularly validated to clear possible redundant or incorrect records.

In 2004, 77 paediatricians and 41 general practitioners providing care to a total of 178,785 patients in 25 cities took part in the ARD data collection.

The data of 2004 do not markedly differ from those from previous years with the monthly incidence rates ranging from tens to hundreds of cases per 1,000 population of a given age group depending on season and epidemiological situation. In 2004, the monthly ARD incidence (excluding influenza) in children of different age groups varied widely from 2 (Havlíčkův Brod) to 826 (Hradec Králové) cases per 1,000 children. As in previous years, the highest ARD morbidity was recorded in the age group 1 to 5 years. In most cities, the ARD morbidity shows seasonal trend with a typical downward tendency in summer, being most marked in the age group 1–5years, less marked in children aged from 6 to 14 years and least marked in adults.

Figs. 4.1a and 4.1b show the highest and the lowest monthly ARD incidence rates, mean monthly ARD incidence rates in 2004 and the range of the mean monthly ARD incidence rates for 1995–2004. The mean monthly ARD incidence rates in children aged from 1 to 14 years recorded in 2004 were mostly close to the lower limit of the mean values range of previous years, with the exception of the age group 1 to 5 years (Fig. 4.1a) in Hodonín, Hradec Králové and Šumperk (in Hradec Králové and Šumperk, the rates of 2004 are the highest in the last decade) and the age group 6 to 14 years (Fig. 4.1b) in Hradec Králové, Olomouc and Příbram. In 2004, the slight downward trend in ARD morbidity (excluding influenza), affecting both upper and lower airways, continued. A more marked decline was recorded in children aged 6 to 14 years compared to 1–5 year-olds. A 3 % rise was recorded in the incidence of ARD of lower airways due to higher frequency of bronchitis (increased from 7 % in 2003 to 9 % in 2004) and pneumonia (increased from 0.5 % in 2003 to 1.5 % in 2004).

As in previous years, diseases of the upper respiratory tract were responsible for the major share in the total ARD morbidity, accounting for 75 % of the morbidity on average (for all the monitored cities and age categories). Influenza was the second with 10 %, followed by acute bronchitis with 9 %. The order of the remaining diagnoses by frequency was the following: otitis media – rhinosinusitis – mastoiditis (2.9 %), pneumonia (1.5 %) and asthma (1.2 %).

4.3 Urban air pollution

In 2004, data on air pollutant concentrations measured at 90 stations (46 stations operated by the Public Health Institutes and 44 stations of the National Immission Network) located in 27 cities involved in the Monitoring System (see Tab. 3.1 and Fig. 3.1) were analyzed. For 2004, data on sulphur dioxide, nitrogen dioxide and PM10 concentrations are available from all localities and those on mass concentrations of selected metals (arsenic, chromium, cadmium, manganese, nickel and lead) were provided by the stations operated by the Public Health Institutes. Depending on automated stations, additional data on nitrogen oxide, ozone, carbon oxide and newly also PM2.5 are variably obtained. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) continue to be monitored selectively in a number of the monitored cities.

The criteria of Government Order No. 350/2002 of August 14, 2002 as last amended in Government Order No. 60/2004, laying down the ambient air pollution limit values and conditions and ways of air quality monitoring, assessment, evaluation and management, were applied to assess the recorded and calculated pollutant concentrations. Reference values (recommended as the highest values) set by the air hygiene working group of NIPH according to Article 45 of Act No. 86/2002 (as last amended in Act No. 92/2004) were used for pollutants with no limit established, and the limit concentrations in force until 2002 were taken as reference values for evaluation of the TSP fraction and sum of nitrogen oxides.

Health risks assessment was focused on carcinogenic pollutants such as arsenic (As), nickel (Ni), benzo[a]pyrene (BaP) and benzene for which carcinogenic risk levels have been defined. Risk levels were taken from the WHO web site www.who.dk/air/activities/20020620-1.

4.4 Inorganic contaminants of urban air

After an extremely dry year with extreme pollution levels in 2003, long-term trends in commonly monitored pollutants continued in 2004.

The annual arithmetic mean of sulphur dioxide (SO2) concentrations was not higher than 14 µg/m3, i.e. 30 % of the concentration limit (50 µg/m3) in any of the cities monitored in 2004. This maximum value was recorded in Karviná (Fig. 4.2a). The limit 24-hour concentration of 125 µg/m3 was not exceeded in any of the cities monitored.

Outdoor air ozone concentrations have been monitored in 16 cities. The annual arithmetic means ranged between 32.6 µg/m3 and 58.3 µg/m3 (Fig. 4.2b). 24-hour concentrations exceeded 120 µg/m3 only in isolated instances (Ústí nad Labem, Prague). In 2004, no ozone episode (exceedance of the hourly value of 180 µg/m3) was recorded at the Public Health Service stations.

Particulate matter (PM10) concentrations in outdoor air fluctuated around the lower limit of the concentration range of the previous years in most cities in 2004 (Fig. 4.2c, 4.2d). A marked decrease in PM10 concentrations was recorded in all cities compared to extremely high concentrations established in 2003. In 2004, the annual limit specification for PM10 (annual arithmetic mean of 40 µg/m3 or more than 35 exceedances of the 24-hour limit of 50 µg/m3) was exceeded in 10 of 27 cities. The 24-hour limit was exceeded more than 35 times in all monitored Prague districts but Prague 10; in Prague 5 such exceedance was recorded for 75 days. In three cities (Kroměříž, Ostrava, Děčín) and one Prague district (Prague 2) only the annual arithmetic means were higher than 40 µg/m3.

The annual arithmetic means of the sum of nitrogen oxides (NOx) ranged from 22.6 to 116.9 µg/m3 in 2004 (Fig. 4.2e). As in previous years, the level of 80 µg/m3 (used as a comparative value) was exceeded in several Prague districts, with the highest ever levels being recorded in Prague 2 (hot spot in Legerova street with 116.9 µg/m3) and Prague 9 (95.5 µg/m3). The lowest annual arithmetic mean was established in Kroměříž.

Concentrations of nitrogen dioxide (NO2) exceeded the limit of 40 µg/m3 in Děčín (45.3 µg/m3) and several Prague districts (Prague 1: 43.1 µg/m3, Prague 2: 54.4 µg/m3, Prague 5 and Prague 9: 42.2 µg/m3). The highest annual mean was found for a heavy traffic area in Prague 2 (75.9 µg/m3) where the 24-hour value reached 179 µg/m3 in December 2004. The annual arithmetic means in all the other cities monitored ranged from 10.6 to 37.7 µg/m3, falling below 20 µg/m3, i.e. half the limit, in eight cities (Fig. 4.2f).

The measurement results confirm long-term low or stable concentrations of carbon monoxide (CO). The annual levels varied between 215 and 739 µg/m3. As in previous years, high CO levels persist in heavy traffic areas in Prague (1,000–1,628 µg/m3) with a hot spot in Prague 8 (3,895 µg/m3).

4.4.1 Metals in suspended particulate matter

The mass concentrations of selected heavy metals were obtained by analysis of 14-day-cumulative samples of particulate matter. Air pollution with the elements monitored between 1995 and 2004 either shows a slightly downward tendency (lead) or is rather stable (cadmium, chromium, arsenic), without any significant oscillations.

The annual concentrations of the metals monitored in suspended particulate matter can be described as follows:

4.5 Organic contaminants of urban air

Organic air pollutants with serious health effects are among the monitored substances. Many of them are mutagens or carcinogens which are either bound to suspended particulate matter or present in the form of vapours. Concentrations of these pollutants have been monitored in selected cities, mostly at one measuring station per city; therefore the results obtained are not representative of the situation in the given city as a whole.

4.5.1 Polycyclic aromatic hydrocarbons

In 2004, the monitoring of polycyclic aromatic hydrocarbons (PAHs) was conducted in eight cities: Prague, Brno, Plzeň, Ústí nad Labem, Hradec Králové, Karviná, Žďár nad Sázavou and Ostrava. The following twelve polycyclic aromatic hydrocarbons were monitored according to US EPA TO - 13: phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene and indeno[c,d]pyrene. In Ostrava, only eight selected PAHs have been monitored. The ambient air sampling was performed every sixth day.

The annual limit for benzo[a]pyrene of 1 ng/m3 was exceeded in most of the cities monitored in 2004 (Fig. 4.5a). The highest burden of benzo[a]pyrene was found in Ostrava with an annual mean concentration of 6.5 ng/m3 and Karviná with 4.5 ng/m3. In winter, mean 24-hour concentrations higher than 20 ng/m3 were recorded at these stations on some days. The annual limit was also markedly exceeded in Ústí nad Labem (1.7 ng/m3), Prague 10 (1.6 ng/m3), and Hradec Králové (1.2 ng/m3). The annual mean concentrations in Žďár nad Sázavou and Brno were just below the limit and the lowest concentration was recorded in Plzeň.

The annual arithmetic means of benzo[a]anthracene (Fig. 4.5a) varied widely from 0.9 ng/m3 in Plzeň to 8.5 ng/m3 in Karviná. In contrast to previous years, the annual reference concentration of 10 ng/m3 was not exceeded in any of the monitored localities. In most localities contamination levels were lower than one-third of the reference concentration, higher contamination was recorded in Ostrava (6.7 ng/m3) and Karviná. The annual mean phenanthrene levels did not exceed one tenth of the reference concentration (1,000 ng/m3) in any of the cities monitored. The total annual mean PAH concentration expressed as the sum of PAHs was highest in Karviná (Fig. 4.5a). In the other localities 2–6 times lower values were established. The sum of PAHs could not be calculated for Ostrava where only selected PAHs have been monitored.

The PAHs include several compounds varying in health significance; those considered as probable carcinogens differ in health effects as well. Based on comparison of carcinogenic effects of the concentrations measured for different PAHs with that of benzo[a]pyrene (BaP) as one of the most toxic and best studied carcinogenic polycyclic aromatic compounds, the carcinogenic potential of PAHs in air may be expressed using the toxic equivalent of benzo[a]pyrene (TEQ BaP). The following toxic equivalent factors (TEFs) pursuant to the US EPA were used for the calculation of TEQ:

TEQ BaP conversion factors (US EPA)

PAH

TEF

PAH

TEF

PAH

TEF

Benzo[a]pyrene

1

Benzo[b]fluoranthene

0.1

Dibenz[a,h]anthracene

1

Benzo[k]fluoranthene

0.01

Benzo[a]anthracene

0.1

Indeno[c,d]pyrene

0.1

The concentration of each PAH identified in the mixture is multiplied by the respective TEF and the sum of all products obtained is the TEQ BaP of the PAH mixture studied.

From the very beginning of the monitoring, Ostrava and Karviná have been among the localities at the highest carcinogenic risk from PAHs; in 2004 the highest carcinogenic potential was found in these two cities with annual means of 9.4 ng/m3 and 7.3 ng/m3, respectively. The values in Prague, Hradec Králové Ústí nad Labem and Žďár nad Sázavou varied between 2 and 3 ng/m3. The mean annual TEQ BaP values obtained in different cities between 1997 and 2004 are shown in Fig. 4.5b.

4.5.2 Volatile organic compounds

In 2004, volatile organic compounds (VOCs) in outdoor air were monitored at 6 stations operated by the Public Health Service and 14 stations run by the Czech Hydrometeorological Institute. At the PHS operated measuring stations, forty-two organic compounds were monitored (pursuant to US EPA TO - 14); nevertheless, only twenty-three of these were taken into account since the remaining ones were mostly present in concentrations below the respective detection limits. Winter sampling was carried out on every sixth day, while from April to September, outdoor air samples were collected on every twelfth day. The stations operated by the Czech Hydrometeorological Institute monitored benzene, toluene, ethylbenzene and sum of xylenes. The measurement should be continuous but frequent failures occurred with the system being newly implemented in a number of localities in 2004.

An annual concentration limit of 5.0 µg/m3 has been established for benzene by Government Order No. 350/2002. Among other important VOCs, for which reference concentrations have been set, are aromatic hydrocarbons (toluene, sum of xylenes, styrene, sum of trimethylbenzenes) and chlorinated aliphatic and aromatic hydrocarbons (trichloromethane, tetrachloromethane, trichloroethene, tetrachloroethene, chlorobenzene, and sum of dichlorobenzenes).

In 2004, the limit for benzene was only exceeded at one station, Ostrava-Přívoz (operated by the Czech Hydrometeorological Institute), where the annual mean concentration reached 7.7 µg/m3. Nevertheless, since lower concentrations were established at two other stations in Ostrava the limit was not exceeded for Ostrava as a whole. Annual benzene concentrations close to the limit were recorded in Prague 10 (4.1 µg/m3) and at one of the stations in Ústí nad Labem (4.4 µg/m3). The results of four stations operated by the Czech Hydrometeorological Institute ranged between 1.0 and 2.2 µg/m3 but could be biased by measurement failures. Fig. 4.6a shows annual mean concentrations of benzene in different localities; the figures in Ústí nad Labem and Ostrava are means from multiple measuring stations. Fig. 4.6b represents trends in annual mean concentrations of benzene in different localities between 2000 and 2004 with the clearly highest long-term burden in Ostrava.

Any of the reference VOC concentrations was not exceeded in any of the localities monitored. Annual mean concentrations were mostly below 25 % of the reference VOC levels.

4.6 Assessment of exposure to major pollutants

4.6.1 Air quality index

The Air quality index (AQI) is based on the limit concentrations of the pollutants listed in Government Order No. 350/2002 and specified in later regulations (60/2004). The AQI takes into account annual arithmetic means of concentrations of SO2, NO2, particulate matter PM10, arsenic, cadmium, nickel, lead, benzene and benzo[a]pyrene. In view of the long-term trends and higher variability of measured concentrations of the monitored pollutants, the method for the calculation of AQI was changed. Only concentrations higher than 20 % of the limits established were taken into account. AQIs were calculated for two groups of localities – group 1 comprises localities where common pollutants, toxic metals and benzene are monitored and group 2 includes 8 localities with additional monitoring of polycyclic aromatic hydrocarbons (PAHs).

The AQI values in group 1 ranged from class 2 (acceptable atmosphere) to class 3 (moderately polluted atmosphere) in Prague 1, Prague 2, Prague 5, Prague 8, Prague 9, Děčín and Kroměříž. The PM10 limit was most frequently exceeded. The AQI values are shown in Fig. 4.7a.

In group 2, Žďár nad Sázavou, Brno and Plzeň were classified into class 2, while Ústí nad Labem, Hradec Králové and Prague 10 fell into class 3. Higher air pollution was found in Karviná and Ostrava classified into class 4 (polluted atmosphere) similarly as in 2003. The benzo[a]pyrene and PM10 limits remained most markedly exceeded. The respective AQI values are shown in Fig. 4.7b.

4.6.2 Exposure to ambient air pollutants

The health effects of air pollution depend on the concentration of air pollutants and duration of human exposure. The exposure assessment is complicated by inter- and intra-individual variability. The actual exposure of an individual varies widely over the year and her/his lifetime with job, lifestyle and outdoor/indoor pollutant concentrations. Pollutant concentrations change with the environment (outdoor vs. indoor), locality (city vs. countryside, low traffic vs. heavy traffic areas, industrial vs. non-industrial zones), time (seasonal trends, daily variability) and climatic conditions. The mean long-term exposure to pollutants can be expressed as potential exposure of the population of a given locality to the mean pollutant concentration level as the supply stratified e.g. at limit concentration intervals.

The assessment of the risk from outdoor air pollution included exposure to sulphur dioxide as an indicator of coal incineration, nitrogen dioxide indicative of incineration processes of other types, e.g. those associated with gas heating and traffic, and suspended PM10 as the generally monitored indicator of highest health significance. Population exposure to outdoor air pollutants in the cities monitored at limit concentration intervals is represented in Fig. 4.4.

The mean long-term exposure to sulphur dioxide is low and did not exceed 20 µg/m3, i.e. 40 % of the exposure (concentration) limit, for 99 % of the monitored population in 2004. Since 1999, this exposure can be considered as stable and close to the natural background exposure.

Levels of exposure to nitrogen oxides, represented by nitrogen dioxide, remain higher and more significant. Exposure levels are rather stable in a long-term run, but the concentration range increases; 55.9 %, 39.4 % and 1.5 % of the population monitored are long-term exposed to concentrations below 27 µg/m3, between 27–40 µg/m3 and above the limit, respectively.

The population exposure to suspended PM10 continues to be of concern. The criteria established by Government Order No. 350/2002 were exceeded for 72.2 % of the population monitored in 2004. Exposure may be characterized as long-term, with slowly increasing mean values. The proportion of the population living in the localities where the concentration limit was exceeded slightly decreased compared to 2003.

4.6.3 Health risk assessment of carcinogens

Another possibility for air pollution assessment is health risk estimate. Theoretical increase in cancer risk from exposure to arsenic, nickel, benzo[a]pyrene and benzene in ambient air was calculated. The estimate was based on a linear no-threshold dose-effect model.

Unit cancer risk (UCR)

Pollutant

Arsenic

Nickel

Benzo[a]pyrene

Benzene

UCR

1.50E-03

3.80E-04

8.70E-02

6.00E-6

Long-life exposure to particular pollutants was considered and based on annual arithmetic mean levels for 2004 the risk estimates were calculated for inhabitants of each city monitored. The aggregate cancer risk is the sum of the risks from individual pollutants. The population risk, i.e. the annual excess cancer risk to the total monitored population, was calculated from the individual risk multiplied by the number of individuals in the exposed population of the monitored city and divided by the life expectancy (70 years).

The results are summarized in the health risk table. For all of the assessed pollutants, the minimum health risk, maximum health risk and mean health risk (arithmetic mean, AVG) as well as the population risk for the cities with measurement and for all the monitored cities are given.

Health risk 2004

Pollutant

Excess health risk

Population risk

Minimum

Mean (AVG)

Maximum

Cities with
measurement

Estimate for all cities
in Monitoring System

Arsenic

2.3E-07

3.0E-06

9.2E-06

0.119

0.127

Nickel

2.3E-07

8.2E-07

3.6E-06

0.026

0.036

Benzo[a]pyrene

3.3E-05

1.7E-04

5.7E-04

3.925

7.425

Benzene

4.0E-06

1.3E-05

2.9E-05

0.341

0.526

Total (for 3.34 million population)

4.411

8.114

Excess health risk for particular pollutants ranges between 10-7 and 10-4, with the highest contribution of benzo[a]pyrene. It can be estimated that overall exposure to four assessed pollutants could theoretically contribute to the development of 4.4 cancer cases among 3.34 million population of the monitored cities per year. This estimate does not include potential effects of the four pollutants in all cities since benzo[a]pyrene has only been followed up in eight of the monitored cities and benzene has been measured in 17 of the monitored cities.

As the benzo[a]pyrene concentrations range from 5E-04 µg/m3 to 6.5E-03 µg/m3 in the eight monitored cities, reaching 3.8E-04 µg/m3 at the Košetice background station, similar levels can be expected in other cities where the monitoring of PAHs is not carried out. In case of data absence the mean values for the monitored cities were used for the total population estimate for all cities of the System of Monitoring. Due to this approach, the aggregate population risk estimate almost doubled, amounting to 8.1 additional cancer cases in 2004.

4.7 Indoor air pollution

A questionnaire survey was part of the INDOOR project focused on indoor air quality measurement in 2003–2004. In 5 cities, i.e. Plzeň, Brno, Hradec Králové, Karviná, and Ostrava, 1,250 dwellins (250 dwellings per city) were randomly selected in collaboration with the Czech Statistical Office and their users were asked to take part in a questionnaire survey.

The questionnaire included 22 questions focused on the following four data categories: household members, daily activities, housing type and lifestyle. The final questionnaire response rate was 56 %. The highest response rate was achieved in Hradec Králové (78 %) while the lowest response rate (38 %) was recorded in Plzeň. Out of 701 respondents 331 (47.2 %) consented to the subsequent measurements and 100 out of their dwellings were randomly selected.

4.7.1 Characteristics of respondents

Data on the household member aged more than 18 years and listed in the first place were taken into account for processing. Characteristics of respondents are summarized in the table below.

Characteristics of respondents

Respondents

Distribution

Age

30–39 years

40–49 years

50–59 years

Other

18.1 %

22.8 %

21.0 %

38.1 %

Education

Primary

Secondary

University

Other

7.1 %

49.2 %

19.6 %

24.1 %

Economic activity

Employed

Unemployed

Retired

Other

54.5 %

3.2 %

31.4 %

10.9 %

When compared with the data of the Czech Statistical Office on the entire Czech Republic (available by December 31, 2003), the study subjects showed comparable age distribution and economic activity distribution but significantly higher proportion of university education.

Housing characteristics

Housing

Distribution

Type

Apartment house

Family house

75 %

25 %

Construction material

Prefab

Bricks

Other

49.5 %

46.8 %

3.7 %

Floor

Ground floor

Higher floor

Double-floor

24.2 %

68.9 %

6.6 %

Area

55 to 64 m2

65 to 74 m2

74 to 100 m2

Other

12.8 %

24.6 %

38.5 %

24.1 %

Number of rooms

2

3

4

Other

12.7 %

59.4 %

19.8 %

8.5 %

4.7.2 Exposure factors

Daily activities: The respondents spend in their dwellings the shortest time in summer on weekend days (12.4 h) and the longest time on winter weekend days (17 h), see Fig. 4.8a.

Time spent to cook meals: 1–2 h (40 %) and 2–3 h (32 %) on week days. On weekend days 2–3 h (35 %) and 3–4 h (29 %); 25 % of the households spend more than four hours to cook meals on weekend days.

Smoking habits: Smokers live in every fifth dwelling (22 %). In most dwellings (61 %), 1 to 10 cigarettes are smoked a day.

4.7.3 Potential sources of indoor air pollution and other factors influencing indoor air quality

Gas cookers, electric cookers or combined cookers are used by 55 %, 11 % and 33 % of households, respectively; statistically significant differences in distribution of cooker types were found between cities (p < 0.001). The highest proportion of gas cookers (75 %) was found in Karviná. A gas water heater is used by 24 % of households. 90 % of households use ventilation or a cooker hood while cooking meals.

Seven % of dwellings have plastic frame windows. Moulds around windows are reported to appear exceptionally in 13 % of households, sometimes in 11 % of households, permanently in 4 % of households and never in 72 % of households. Moulds on the walls are found exceptionally in 9 % of households, sometimes in 9 % of households and permanently in 3 % of households. As many as 79 % of households have never seen moulds in their dwellings. Statistically significant differences in the incidence of moulds were found between cities (p = 0.001). The mould occurrence in dwellings is reported in Fig. 4.8b.

Relationships between the questionnaire data and measurement results were sought for:

A. Relationships between nitrogen dioxide (NO2) levels and the use of gas appliences:

B. Relationships between the incidence of moulds and the use of plastic frame windows:

Paradoxically, the presence of moulds around windows was only found in dwellings without plastic frame windows. Statistically significant differences in the incidence of moulds around windows (p = 0.210) and on the walls (p = 0.582) were not found between dwellings with and without plastic frame windows. One of the reasons can also be the very low number of dwellings with plastic frame windows.

C. Relationships between the incidence of moulds and characteristics of houses and flats:

D. Relationships between smoking habits and indoor levels of benzene, formaldehyde and PM10:

In contrast to what was expected, significantly higher indoor levels of benzene attributable to smoking were not found in flats of smokers compared to those of nonsmokers. This can be explained e.g. by more frequent and regular ventilation in smoker flats and by the fact that nobody smoked in the flats during the measurements. Analysis showed higher variability in the measured pollutant levels between cities than between smoker and nonsmoker dwellings.

4.8 Partial conclusions

The data on treated acute respiratory diseases in 2004 were similar to those obtained in previous years. The ARD incidence rates in the localities monitored varied from several cases to hundreds of cases per 1,000 population of a given age group. As in previous years, the highest ARD incidence was recorded in the age group 1 to 5 years. Upper respiratory tract diseases were the most frequent ARD to be diagnosed. In most localities, the mean annual ARD incidence rates in children aged 1–14 recorded in 2004 were close to the lower limit of the rate range for the past years.

Ambient air quality in the monitored cities was slightly better in 2004 compared to 2003, which was an extreme year in terms of weather and pollution. Traffic-related air pollutants such as PM10, NO2, benzene and benzo[a]pyrene remain of concern. The annual PM10 limit was exceeded in 10 localities (i.e. for 72 % of the monitored population). The benzo[a]pyrene limit is exceeded on a long-term basis at most of the 8 measuring stations. In 2004 compared to 2003, the benzene levels were by 30 to 40 % lower in Karviná and Ostrava where the burden is typically the highest and remained comparable in the other monitored localities. After the gradual increase in NO2 annual arithmetic means between 1995 and 2003, most localities showed either lower or comparable NO2 levels in 2004 compared to 2003 except for Děčín and heavy traffic areas in Prague.

These conclusions are in agreement with human health risk estimates for potential carcinogens. The calculated excess risk for benzo[a]pyrene is 1.7E-04; the estimated risk to the population of the monitored cities is 7.4 new cancer cases, of these 3.1 new cancer cases are expected in the Karviná-Ostrava region and 1.6 new cancer cases are calculated for the Prague conurbation. The calculated excess risk for benzene in 2004 is 1.3E-05; the estimated risk to the population is 0.5 additional cancer cases, with the highest contribution of Ostrava (0.15). The calculated excess risk for arsenic and nickel in 2004 is 3E-06 and 8.2E-07, respectively; the estimated risk to the population is 0.12 and 0.03 new cancer cases, respectively.

The highest air pollution is detected in heavy industrial areas such as Karviná, Ústí nad Labem or Liberec, and in large conurbations such as Prague, Brno and Ostrava where the limits are exceeded for several monitored air quality parameters. Nevertheless, due to the nation-wide increase in heavy traffic, hot spots are found in other cities as well.

Statistical analysis of the questionnaire survey carried out within III. phase, i.e. indoor air quality screening in dwellings of the commonest size in the Czech Republic, revealed gas or combined cookers to be associated with significantly higher indoor air pollution levels and the use of ventilation or cooker hoods to have positive effect in this regard. Any effect of gas water heaters on indoor air quality was not proved. The indoor presence of moulds around windows and on the walls was recorded in almost 30 % of households and was permanent in 3.7 % of instances; apartment houses compared to family houses appeared to be at nonsignificantly higher risk for the presence of moulds and ground floor flats compared to higher floor flats or double-floor flats were at significantly higher risk for the presence of moulds. Residents of 22 % of dwellings are smokers, with 1 to 10 cigarettes being smoked a day in 61 % of dwellings. Higher concentrations of benzene, formaldehyde and PM10 were not found in smoker dwellings; this can be explained by more frequent and regular ventilation in smoker dwellings as well as by the fact that nobody smoked in the dwellings during the measurements.

Fig. 4.1a Treated acute respiratory diseases excluding influenza children 1–5 years, 1995–2004
Fig. 4.1b Treated acute respiratory diseases excluding influenza children 6–14 years, 1995–2004
Fig. 4.2a Sulphur dioxide, 1995–2004, annual arithmetic mean 2004
Fig. 4.2b Ground ozone, 1997–2004, annual arithmetic mean 2004
Fig. 4.2c Particulate matter, fraction PM10, 1995–2004, annual arithmetic mean 2004
Fig. 4.2d Particulate matter pollution, PM10, frequency of 24-hour limit exceedings
Fig. 4.2e Sum of nitrogen oxides, 1995–2004, annual arithmetic mean 2004
Fig. 4.2f Nitrogen dioxide, 1995–2004, annual arithmetic mean 2004
Fig. 4.3a Arsenic in particulate matter
Fig. 4.3b Cadmium in particulate matter
Fig. 4.3c Lead in particulate matter
Fig. 4.3d Chromium in particulate matter
Fig. 4.3e Manganese in particulate matter
Fig. 4.4 Distribution of the population by the potential exposure to selected air pollutants (in intervals of the annual limit IHr)
Fig. 4.5a Polycyclic aromatic hydrocarbons (PAHs), annual arithmetic mean 2004
Fig. 4.5b Benzo[a]pyrene Toxic Equivalent TEQ (BaP) in 1997–2004
Fig. 4.6a Volatile organic compounds – Benzene, 2004
Fig. 4.6b Trend of benzene concentration levels in 2000–2004
Fig. 4.7a Air Quality Index – I.
Fig. 4.7b Air Quality Index – II.
Fig. 4.8a Proportion of daytime spent indoors
Fig. 4.8b Mould occurrence in the dwellings

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