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 measuring stations 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

Acute respiratory diseases (ARD) account for a significant percentage of the total morbidity and are the most frequently reported diagnosis in childhood. Therefore, the ARD incidence is used as an important indicator of population health. Epidemiological situation, climatic conditions, air pollution, individual characteristics and last but not least the physician’s subjective evaluation are the major factors influencing the ARD incidence.

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 among 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 data.

In 2005, 70 paediatricians and 39 general practitioners providing care to a total of 173,417 patients in 25 cities took part in the ARD data collection. The data were processed on a monthly basis and only those from physicians providing service for not less than 10 days of the given month were taken into account. If not stated otherwise, the presented results are the average data of the calendar year 2005.

The data of 2005 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. Fig. 4.1a presents the range of monthly ARD incidence rates, excluding influenza, in 2005 for the age group 1–5 years, showing the peak morbidity. The incidence of treated ARD in children in 1995–2005 has become more or less stable after a clear downward trend in 1995–2002 (Fig. 4.1b).

Diseases of the upper respiratory tract accounted for the highest percentage, i.e. 74 %, of the total annual ARD incidence as calculated for all localities and age categories. The second most frequent diagnosis was influenza with 15.1 %, followed by acute bronchitis with 7.4 %. The order of the remaining diagnoses by frequency was the following: otitis media – rhinosinusitis – mastoiditis (2.0 %), pneumonia (0.9 %) and asthma (0.6 %).

4.3 Urban air pollution

In 2005, data on air pollutant concentrations in 38 localities, measured at 77 stations, of these 37 operated by the Public Health Service and 40 belonging to the National Network of the Czech Hydrometeorological Institute (see Tab. 3.1 and Fig. 3.1), were analyzed. The measuring network was optimized through coordination with the Czech Hydrometeorological Institute. To meet the requirements of the Ministry of Health, data from measuring stations operated by the Public Health Service in additional localities (Lovosice, Litoměřice, Litvínov, Teplice, Tanvald, Mariánské Lázně, Meziboří) where Subsystem I has not been run as initially planned were also taken into account. Furthermore, data from two background EMEP (Co-operative programme for the monitoring and evaluation of the long range transmission of air pollutants in Europe) stations at Košetice (No. ISKO 1138) and Bílý Kříž (No. ISKO 1214) operated by the Czech Hydrometeorological Institute and from Prague hot spot stations in Legerova street (No. ISKO 1483), Svornosti street (No. ISKO 437) and Sokolovská street (No. ISKO 446) were included for comparison.

For 2005, data on the major pollutants measured (sulphur dioxide, nitrogen dioxide and PM10) and selected metals (arsenic, chromium, cadmium, manganese, nickel and lead) are available from all localities. Depending on the equipment of the automated stations, additional data on nitrogen oxide, ozone, carbon oxide and 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. Data on heavy metals (11 stations) and polycyclic aromatic hydrocarbons (13 stations) from the network operated by the Czech Hydrometeorological Institute were newly included in 2005.

Air pollution limits and conditions and ways of air quality monitoring, assessment, evaluation and management (L – limit, TL – target limit) laid down in Government Order No. 350/2002 of August 14, 2002 as last amended in Government Order No. 429/2005 were applied to assess the recorded and calculated pollutant concentrations while reference concentrations set by the Air Quality Research Group of the National Institute of Public Health pursuant to Article 45, Act No. 86/2002 (as last amended in Act No. 92/2004) were used for pollutants whose limits had not been established.

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. The risk levels were taken from the WHO web site www.who.dk/air/activities/20050223_3.

4.3.1 Inorganic contaminants of urban air

4.3.1.1 Major pollutants monitored

Long-term trends in most monitored air pollutants continued in 2005.

The annual arithmetic mean of sulphur dioxide concentrations (Fig. 4.2a) did not exceed 15 µg/m3 in any of the cities monitored, with the exception of station No. ISKO 929 in Litvínov (23.3 µg/m3). The limit 24-hour concentration of 125 µg/m3 was exceeded at stations No. ISKO 1064 in Ostrava and No. ISKO 1120 in the Litoměřice district. The average long-term sulfur dioxide exposure is stably low, about twice as high as the background level – see annual sulfur dioxide emission characteristics at the background stations of the Czech Hydrometeorological Institute, i.e. 3.4 µg/m3 at Košetice and 5.7 µg/m3 at Bílý Kříž. Air pollution trend in cities with the highest last annual sulfur dioxide concentrations is shown in Fig. 4.2b.

The annual arithmetic means of the sum of nitrogen oxides (NOx) ranged from 6.2 to 176.8 µg/m3 in 2005. The annual characteristics at the backround stations of the Czech Hydrometeorological Institute did not exceed 10 µg/m3 (10.5 µg/m3 at Košetice and 7.3 µg/m3 at Bílý Kříž). The annual arithmetic mean of 80 µg/m3 was exceeded at five measuring stations in Prague, with the highest level recorded in Prague 2 for the traffic hot spot in Legerova street. Air pollution with the sum of nitrogen oxides shows a stable trend without marked fluctuations.

The annual mean particulate matter (PM10) concentrations in outdoor air varied from 23 to 50 µg/m3 (Fig. 4.3a). After a slight downward trend in 2004, higher concentrations were measured in 2005 again (Fig. 4.3b). In 2005, at least one annual PM10 limit (annual aritmetic mean of > 40 µg/m3 and/or more than 35 exceedances of the 24-hour limit of 50 µg/m3) was exceeded in 19 monitored cities, among others in all Prague districts, overall at 57 % of the measuring stations (Fig. 4.3c). The highest number of days with concentration above 50 µg/m3, i.e. 160, was recorded at station No. ISKO 1410 in Ostrava. The 24-hour limit was exceeded at least once at all of the measuring stations. The annual arithmetic mean at the background station Košetice was 28.3 µg/m3, with more than 35 exceedances of 50 µg/m3 per year, which is comparable with the data obtained in the cities monitored. Therefore, a higher level of PM10 air pollution is characteristic of the whole Czech Republic.

PM2.5 concentrations continued to be monitored in 2005 at selected stations in Prague and 13 other localities. The annual mean PM2.5 concentrations varied from 18.5 to 433 µg/m3. The annual mean of 20 µg/m3 was exceeded at 17 of 18 monitoring stations, the target annual mean PM2.5 concentration of 25 µg/m3 proposed by the new draft framework EU directive was exceeded in Brno, Kladno, Teplice, Hradec Králové, Olomouc and Ostrava while an annual mean PM2,5 concentration higher than 30 µg/m3 was recorded at two monitoring stations Nos. ISKO 1410 and 1064 in Ostrava.

In 2005, nitrogen dioxide air pollution levels were monitored at 76 stations in 39 localities (Fig. 4.5a). The natural background nitrogen dioxide levels in the Czech Republic do not exceed 10 µg/m3 (9.9 µg/m3 at Košetice and 7.1 µg/m3 at Bílý Kříž). The annual mean nitrogen dioxide levels at heavy traffic hot spots in Prague, i.e. Legerova street (No. ISKO 1483), Svornosti street (No. ISKO 437) and Sokolovská street (No. ISKO 446), were almost twice as high as the limit, which was also exceeded in Děčín (No. 576) where 50.2 µg/m3 was recorded. Nitrogen dioxide air pollution shows a slightly upward trend, with the annual limit being exceeded at more than half of Prague monitoring stations, i.e. at 14 of 22 stations.

Outdoor air ozone concentrations have been monitored in 16 cities. The annual arithmetic means ranged between 32.6 µg/m3 and 67.1 µg/m3 (Fig. 4.6a). In 2005, no ozone episode (exceedance of the hourly value of 180 µg/m3) was reported by the Public Health Service stations; data from stations operated by the Czech Hydrometeorological Institute were not available at the time when the Summary Report was being elaborated.

Carbon monoxide air pollution was monitored at 34 stations in 20 localities. The annual background carbon monoxide level in the Czech Republic was about 300 µg/m3 (Košetice), the annual arithmetic means did not exceed 700 µg/m3, with the exception of heavy traffic hot spots (Legerova, Svornosti and Sokolovská streets in Prague) where they reached about 1,000 µg/m3.

4.3.1.2 Metals in suspended particulate matter

The mass concentrations of selected heavy metals were obtained by analysis of 14-day-cumulative samples of particulate matter. After showing a slightly downward tendency, air pollution with the elements monitored between 1995 and 2005 has become rather stable, without any significant oscillations.

The target annual limit for arsenic was exceeded at station No. ISKO 411 in Tanvald (0.0072 µg/m3). The annual aritmetic means at the other stations ranged from 0.0005 µg/m3 (Meziboří) to 0.0059 µg/m3 (Ostrava) (Fig. 4.8a) and did not exceed 0.002 µg/m3, i.e. were close to those observed at background stations, at 34 of 57 stations.

The target annual limit for cadmium was exceeded almost three times at station No. ISKO 411 in Tanvald (0.0142 µg/m3) (Fig. 4.10a). In most monitored localities, the annual arithmetic mean did not exceed 1/5 of the limit (0.001 µg/m3), i.e. the natural background level; only stations in Příbram, Liberec and Ostrava reported levels close to half the limit.

The limit and WHO level recommended for lead were not exceeded at any of the monitoring stations in 2005. The recorded levels varied from 1 % to 10 % of the limit and good agreement between the annual arithmetic and geometric means in most localities indicates stability and homogeneity of the data, without significant seasonal, climatic or other oscillations (Fig. 4.11a).

No annual chromium limit has been established. Based on the WHO recommendation, a reference concentration of 2.5*10-5 µg/m3 was determined for hexavalent chromium (Cr+VI) but cannot be used to assess the total chromium concentration in outdoor air (variable mixture of Cr+III plus Cr+VI with the estimated contribution of the latter varying from 10 % to 0.001 %, i.e. within 4 orders of magnitude). The annual arithmetic mean total chromium levels ranged from 0.00072 µg/m3 in Olomouc to 0.0389 µg/m3 at station No. 472 in Kladno. In most of the cities monitored, the level of 0.005 µg/m3 was not exceeded (Fig. 4.12).

The target nickel limit was not exceeded at any of the monitoring stations in 2005. The annual arithmetic means of nickel levels ranged from 0.00072 µg/m3 (Havlíčkův Brod) to 0.0082 µg/m3 (Děčín and Kroměříž), i.e. did not exceed 40 % of TL (Fig. 4.9). The levels observed at the background stations at Košetice (0.001 µg/m3) and Bílý Kříž (0.0007 µg/m3) are close to the range bottom while the levels reported in polluted areas are even 12 times as high.

In 2005, the annual arithmetic means of manganese levels ranged from 0.001 µg/m3 in Meziboří to 0.0516 µg/m3 in Prague 8, with the exception of the industrially polluted area monitored by station No. ISKO 1457 in Ústí n/Labem. The levels at the background stations at Košetice (0.00519 µg/m3) and Bílý Kříž (0.0052 µg/m3) fall in the middle of the range observed (Fig. 4.13).

4.3.2 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 a given city as a whole.

4.3.2.1 Polycyclic aromatic hydrocarbons

In 2005, the monitoring of polycyclic aromatic hydrocarbons (PAHs) was conducted in 17 localities at 21 stations (after inclusion of those operated by the Czech Hydrometeorological Institute). At 14 stations, twelve polycyclic aromatic hydrocarbons were monitored according to US EPA TO – 13. Other seven included stations only monitored a limited range of particulate bound higher molecular compounds collected on silica filters. The ambient air sampling was performed every sixth day.

The annual limit for benzo[a]pyrene of 1 ng/m3 was exceeded at 17 stations (81 %) in 2005. The highest burden of benzo[a]pyrene was found at two Ostrava stations with annual mean concentrations of 9.2 ng/m3 and 5.5 ng/m3 and in Karviná with 3.1 ng/m3 (Fig. 4.7a). In winter, mean 24-hour concentrations even higher than 30 ng/m3 were recorded at these stations. The target annual limit was also markedly exceeded in Prague, Brno, Olomouc, Hradec Králové, Plzeň, Ústí nad Labem, Liberec, Most, Teplice and Kladno. On the other hand, the lowest benzo[a]pyrene concentrations recorded in Sokolov and Žďár nad Sázavou (0.8 ng/m3) were comparable with those obtained at the background station at Košetice (0.6 ng/m3).

The annual arithmetic means of benzo[a]anthracene (BaA) varied widely from 0.8 ng/m3 to 10.2 ng/m3 (Fig. 4.7a). The annual reference concentration was exceeded at station No. ISKO 1467 in Ostrava. A long-term upward trend was confirmed for two stations in Ostrava and Karviná (5.1 to 8.9 ng/m3). At the other stations, the annual levels were lower than a third of the reference concentration.

The total annual mean PAH concentration expressed as the sum of PAHs was highest (189.3 ng/m3) at station No. ISKO 1410 in Ostrava. Higher burden was confirmed for the Ostrava-Karviná region while the other localities showed 2 to 6 times lower levels.

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 (BaP TEQ). Toxic equivalent factors (TEFs) were used for the calculation of TEQ pursuant to the US EPA (see Table). The concentration of each PAH identified in the mixture is multiplied by the respective TEF and the sum of all products obtained is the BaP TEQ of the studied mixture of PAHs.

Toxic equivalent factors

 

TEF

 

TEF

 

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

From the very beginning of the monitoring, Ostrava and Karviná have been among the localities at the highest carcinogenic risk from PAHs; in 2005 the highest carcinogenic potential was found at station No. 1467 in Ostrava (annual mean of 12.6 ng/m3) and was several times as high as in the other monitored cities. Station No. 517 in Karviná showed the lowest level, i.e. 4.8 ng/m3, ever obtained over the 8-year monitoring period (see Fig. 4.7b showing the trend in BaP TEQ over 1997–2005).

4.3.2.2 Volatile organic compounds

In 2005, volatile organic compounds (VOCs) in outdoor air were monitored at 6 stations operated by the Public Health Service and 15 stations of the Czech Hydrometeorological Institute. At the PHS 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 at 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 used automated analyzers to monitor benzene, toluene, ethylbenzene and sum of xylenes.

An annual limit of 5.0 µg/m3 has been established for benzene by Government Order No. 350/2002 as last amended. 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 2005, benzene air pollution was monitored at 21 stations. The mean annual concentration exceeded the set limit at three stations in Ostrava and 1 station in Prague (traffic hot spot in Legerova street). The highest annual mean benzene concentration, 10.26 µg/m3, was recorded at station No. 1467 in Ostrava. In the other monitored cities, the concentrations ranged between 0.8 and 3.94 µg/m3 (Fig. 4.4). Compared to 2005, benzene air pollution slightly increased in the monitored cities.

Any of the other reference VOC concentrations was not exceeded in any of the monitored localities. Annual mean concentrations were mostly below 25 % of the reference levels (see sums of xylenes in Fig. 4.4), only trichloroethene reached 1.33 µg/m3, i.e. more than half the respective reference concentration, at station No. ISKO 1467 in Ostrava.

4.4 Assessment of exposure to major pollutants

4.4.1 Air quality index

The Air quality index (AQI) is based on the limit concentrations (L – limit, TL – target limit) of the pollutants listed in Government Order No. 350/2002 as last amended in Government Order No. 429/2005. AQI takes into account annual arithmetic means of concentrations of sulfur dioxide, nitrogen dioxide, 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 AQI calculation was modified, with only concentrations higher than 20 % of the set target limits being taken into account.

The AQI calculation procedure is given at www.szu.cz/chzp/ovzdusi/dokumenty/index.htm. AQIs were calculated for two groups of localities: group 1 including localities where common pollutants are monitored, and group 2 including 16 localities with additional monitoring of polycyclic aromatic hydrocarbons (PAHs).

The AQI values in group 1 ranged from class 2 (acceptable air quality) to class 4 in Prague 2, Prague 9 and Tanvald (station No. 411), with high arsenic and cadmium pollution levels. The PM10 limit was most frequently exceeded in this group. The AQI values are shown in Fig. 4.14 and compared with those calculated for the background station of the Czech Hydrometeorological Institute at Bílý Kříž (0.646) and the traffic hot spot in Legerova street in Prague 2 (3.353).

In group 2, Žďár nad Sázavou and Sokolov were classified into air quality class 2 while most monitored cities fell into class 3. The benzo[a]pyrene and PM10 limits remained most frequently exceeded and the nitrogen dioxide limit often failed to be observed as well. The AQI values are shown in Fig. 4.14, with that for the Košetice background station (1.565) presented for comparison.

4.4.2 Exposure to 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, depending on 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 for a stratified supply, e.g. at limit concentration intervals.

The assessment of the risk from outdoor air pollution included exposure to nitrogen dioxide indicative of combustion and incineration processes associated in particular with gas heating and traffic pollution, benzene and suspended PM10 as the generally monitored indicator of highest health significance. Distribution of the monitored population by potential exposure to outdoor air pollutants (at limit concentration intervals) is shown in Fig. 4.15.

Levels of exposure to nitrogen oxides, represented by nitrogen dioxide, remain higher and significant. The range of nitrogen dioxide exposure levels was rather stable in most monitored cities. Compared to 2004, a higher proportion of the population was exposed to levels above the limit, particularly in the Prague conurbation where the limit was exceeded at more than half of the monitoring stations. In 2005, 48.7 %, 16 % and 35 % of the monitored population were exposed to concentrations below 27 µg/m3, between 27–40 µg/m3 and above the limit, respectively.

In 2005, 9 % of the monitored population were exposed to outdoor air benzene concentrations exceeding the limit.

The population exposure to suspended PM10 continues to be of concern. The PM10 annual limit was exceeded for 81 % of the monitored population. PM10 exposure can be characterized as general and long-term, with slowly increasing mean values.

4.5 Health risk assessment of carcinogens

Theoretical increase in cancer risk from long-term exposure to outdoor air pollutants was calculated for arsenic, nickel, benzo[a]pyrene and benzene. The estimate was based on a linear no-threshold dose-effect model. The Table below gives unit cancer risk (incremental cancer risk from lifetime exposure to a given air pollutant at a concentration of 1 µg/m3) values for the major pollutants.

Pollutant

Arsenic

Nickel

BaP

Benzene

Unit Cancer Risk

1.50E-03

3.80E-04

8.70E-02

6.00E-6

Lifetime exposure to particular pollutants was considered; based on annual arithmetic mean levels for 2005 the risk estimates were calculated for the population of each monitored city. The aggregate cancer risk is the sum of the risks from individual pollutants. The population risk, i.e. the annual incremental cancer risk to the total monitored population, was calculated from the individual risk multiplied by the exposed population of the monitored city and divided by the life expectancy (70 years). Table 4.1 summarizes the data calculated for the background stations at Košetice and Bílý Kříž, minimal, maximal and mean (arithmetic mean) health risk values, relative contributions of each of the monitored pollutants and the aggregate population risk.

Incremental health risk for particular pollutants ranges between the orders of magnitude of 10-7 and 10-4, with the highest contribution of benzo[a]pyrene. When the mean values obtained for particular cities are used for the estimation of BaP and benzene concentrations in the cities where these pollutants are not routinely measured, it can be estimated that in 2005 overall exposure to these two pollutants could theoretically contribute to 6.87 incremental cancer cases among 3.23 million population.

When lifetime (70-year) exposure to the pollutant concentrations recorded in 2005 is considered, it would mean 481 incremental cancer cases among 3.23 million population of the monitored cities. When extrapolated to the 10 million population of the Czech Republic, the respective figures would be 21 incremental cancer cases in 2005 and 1,489 incremental cancer cases for lifetime exposure to the given air pollutants.

Compared to 2004 the population risk slightly decreased, with a clear reduction (by 1.124) in risk from benzo[a]pyrene. As the ranges of the measured concentrations remained unchanged, a possible explanation for this phenomenon is a higher proportion of less exposed localities after inclusion of data from 13 stations operated by the Czech Hydrometeorological Institute.

4.6 Partial conclusions

The data on treated acute respiratory diseases in 2005 were similar to those obtained in previous years. The ARD incidence rates in the monitored localities varied from several cases to hundreds of cases per 1,000 population of a given age group, depending on season and epidemiological situation. As in previous years, the highest ARD incidence was recorded in the age group 1 to 5 years. Upper respiratory tract diseases (74 %) were the most frequent ARD to be diagnosed. The clearly downward trend in treated acute respiratory diseases in childhood in 1995–2003 has been followed by more or less stable ARD incidence rates.

The outdoor air quality in the monitored cities was slightly worse in 2005 compared to 2004, mainly due to suspended PM10 pollution. Traffic-related air pollutants such as PM10, nitrogen dioxide, benzene and benzo[a]pyrene, whose emissions increase with traffic becoming heavier, remain of concern. The annual PM10 limit was exceeded in 19 localities (i.e. for 81 % of the monitored population). PM2.5 air pollution is also of concern since the target annual level of 25 µg/m3 as set by the EU Framework Directive has been exceeded at nearly half of the measuring stations. The characteristics of nitrogen dioxide air pollution in most monitored cities are comparable to those of 2004, with the limit being exceeded in heavy traffic areas and large conurbations.

Among the monitored heavy metals, cadmium and arsenic are of greatest concern since their target limits were exceeded in Tanvald; levels up to half of the limit were recorded for the most exposed localities in other cities.

The target benzo[a]pyrene limit has been exceeded on a long-term basis at most measuring stations which is also true of the 13 additional stations operated by the Czech Hydrometeorological Institute and included in the project in 2005.

The benzene levels were comparable to or slightly higher than those of 2004; in 2005 the limit for benzene air pollution was exceeded in the Ostrava-Karviná region and at a Prague station situated in a heavy traffic area, long reported to have the highest air pollution level.

Health risk assessment of potential carcinogens was carried out. The incremental cancer risk from benzo[a]pyrene in 2005 was 6.4*10-5, i.e. 6.4 incremental cancer cases per 100,000 population. The estimated population risk in the monitored cities with 3.23 million population in 2005 was about 6 incremental cancer cases, including 2.8 cases expected in the Ostrava-Karviná region and 0.85 cases expected in the Prague conurbation. The incremental cancer risk from benzene was 4.9*10-6, i.e. nearly 5 cases per 1 million population. The estimated population risk was 0.4 incremental cancer cases, again with the greatest contribution of the Ostrava-Karviná region (0.2 cancer cases). The incremental cancer risk from arsenic and nickel was 2.7 incremental cancer cases per 1 million population and 8.6 incremental cancer cases per 10 million population, respectively. The estimated population risk in the monitored cities was 0.11 incremental cancer cases from arsenic exposure and 0.04 incremental cancer cases from nickel exposure.

Heavy air pollution is recorded in industrial localities such as Karviná, Ústí nad Labem and Liberec and in large conurbations (Praha, Brno, Ostrava), with the limits being exceeded for multiple air quality parameters. Pollution hot spots are also found in other cities, as a result of increasing traffic, as well as in rural areas, due to the renewed interest in fossil fuels for local heating prompted by rising energy costs.

Tab. 4.1 Individual and population risk of increase the probability of contracting cancer due to exposure to air pollutants

Pollutant

Individual health risk – 2005

Population risk – 2005

Estimate for monitored cities/year

Background

Minimum

Mean

Maximum

Arsenic

1.66E-06

8.17E-07

2.73E-06

1.08E-05

0.113

Nickel

3.17E-07

2.64E-07

8.62E-07

2.78E-06

0.042

Benzo[a]pyrene

5.87E-05

5.30E-05

6.43E-05

5.81E-04

6.301

Benzene

4.89E-06

4.79E-06

4.89E-06

3.48E-05

0.414

Monitored cities (overall 3.23 mil. inhabitants)

6.870


Fig. 4.1a Treated cases of acute respiratory diseases (excluding influenza)in children 1–5 years, 2005
Fig. 4.1b Trend in treated cases of acute respiratory diseases in children, comparison with the mean year (1995–2005)
Fig. 4.2a Sulphur dioxide, 1995–2005
Fig. 4.2b Trend in sulphur dioxide air pollution
Fig. 4.3a Particulate matter, fraction PM10, 1996–2005
Fig. 4.3b Trend in PM10 air pollution
Fig. 4.3c Particulate matter PM10 frequency of 24-h limit exceedances
Fig. 4.4 Concentrations of benzene and sum of xylenes
Fig. 4.5a Nitrogen dioxide, 1995–2005
Fig. 4.5b Trend in nitrogen dioxide air pollution
Fig. 4.6a Ground ozone levels in 1995–2005
Fig. 4.6b Trend in ground ozone air pollution
Fig. 4.7a Air polycyclic aromatic hydrocarbons (PAHs) annual arithmetic mean 2005
Fig. 4.7b Health risk from PAHs expressed by benzo[a]pyrene toxic equivalent (BaP TEQ)
Fig. 4.8a Arsenic in particulate matter, 2005
Fig. 4.8b Air arsenic concentrations in 1995–2005
Fig. 4.8c Trend in arsenic air pollution
Fig. 4.9 Nickel in particulate matter, 2005
Fig. 4.10a Cadmium in particulate matter, 2005
Fig. 4.10b Air cadmium concentrations in 1995–2005
Fig. 4.11a Lead in particulate matter, 2005
Fig. 4.11b Air lead concentrations in 1996–2005
Fig. 4.12 Air chromium concentrations in 1995–2005
Fig. 4.13 Air manganese concentrations in 2000–2005
Fig. 4.14 Air Quality Index 2005
Fig. 4.15 Distribution of population in participant cities by potential exposure to selected air pollutants (at annual limit intervals IHr)

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