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 and 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 in cooperation with selected public health institutes.
4.2 Incidence of treated acute respiratory diseases
4.2.1 Results 2003
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. The major factors involved in the ARD incidence are the epidemiological situation, climatic conditions, air pollution, individual susceptibility and physician’s subjective evaluation. The information source is 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 with the acronym MONARO. The database is an integrated system that allows continual collection, processing and evaluation of the data on ARD morbidity from general practitioners and paediatricians. The central database is being regularly validated to clear possible redundant or incorrect records.
In 2003, 74 paediatricians and 43 general practitioners providing care to a total of 177,112 patients in 25 cities took part in ARD data collection.
The data of 2003 do not markedly differ from those of 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 2003, the monthly ARD incidence (excluding influenza) in children under 18 years of age varied widely from 3 (Sokolov) to 691 (Šumperk) per 1,000 children. As in previous years, the highest 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. The seasonal trend was found in all age groups of urban population, being most marked in the age group 1–5 years, 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, the mean monthly ARD incidence rates in 2003 and the range of the mean monthly ARD incidence rates for 1995–2003. The mean monthly ARD incidence rates in children aged from 1 to 14 years recorded in 2003 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 and Šumperk and the age group 6 to 14 years in Příbram and Hodonín, showing the highest incidence rates since 1995. A downward trend was detected for all combinations of age group and disease in 1995–2002. The most marked decrease was recorded in the age category 1–5 years, higher age categories showing less marked declines. Morbidity of the lower respiratory tract compared to the upper respiratory tract exhibits a less marked downward trend (Fig. 4.1c).
As in previous years, diseases of the upper respiratory tract were responsible for the major share in the total morbidity, accounting for 76 % of the morbidity on average (for all the monitored cities and age categories). Influenza was the second with 14 %, followed by acute bronchitis with 7 %. The order of the remaining diagnoses by frequency is the following: otitis media – rhinosinusitis – mastoiditis (2.1 %), pneumonia (0.5 %) and asthma (0.5 %).
4.3 Urban air pollution
In 2003, air pollutant concentrations were measured at 76 stations (46 and 32 operated by the Ministry of Health and the Ministry of the Environment, respectively) located in 27 cities involved in the Monitoring System (see Fig. 3.1 and Tab. 3.1). In 2003, sulphur dioxide (SO2 measurements in the Public Health Service network were terminated at all the manual stations; in the cities where a station of the Czech Hydrometeorological Institute is not located, measurements were made during the heating season only), nitrogen oxides – NO/NO2/NOx, particulate matter (TSP and/or suspended PM10 fractions), and mass concentrations of selected metals (arsenic, chromium, cadmium, manganese, nickel and lead) in particulate matter samples were monitored in all cities of the Monitoring System except for Mělník. Concentrations of carbon oxide, ozone, 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 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 orientation values for evaluation of the TSP fraction and sum of nitrogen oxides.
4.4 Inorganic contaminants of urban air
In 2003, long-term trends in development of some commonly monitored pollutants continued.
The annual arithmetic mean of sulphur dioxide (SO2) concentrations was not higher than 23 µg/m3, i.e. 46 % of the concentration limit (50 µg/m3), in any of the cities monitored in 2003. The highest values were recorded in Most (22.7 µg/m3) and Karviná (18.2 µg/m3). The limit 24-hour-concentration of 125 µg/m3 was not exceeded in any of the cities monitored (Fig. 4.2a).
To assess mean annual TSP concentrations, a comparative value of 60 µg/m3 (limit used until 2002) was used as previously (new limit is not currently set). This value was exceeded only for the annual arithmetic mean of TSP in Prague 8 (121.2 µg/m3). The annual means in the other cities range from 20 to 55 µg/m3 (Fig. 4.2b).
Particulate matter (PM10) concentrations in outdoor air were higher as compared to previous years practically in all monitored cities (Fig. 4.2d, 4.2e). The PM10 pollution rises gradually, particularly in big agglomerations; there was showed an increasing linear trend (Prague, Ostrava). In 2003, the annual limit 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 16 cities. In the Prague conurbation an annual weighted (in relation to the monitored zone – i.e. residential, industrial, traffic, etc.) arithmetic mean of 38.6 µg/m3, i.e. a value below the annual mean limit, was recorded. Nevertheless, the 24-hour limit was exceeded more than 70 times in all monitored Prague districts and even 130 times in Prague 5. Only in five out of 21 cities, i.e. in České Budějovice, Liberec, Havlíčkův Brod, Hodonín and Žďár na Sázavou, was the limit not exceeded. The annual mean values ranged from 25 to 51 µg/m3 and thus exceeded the target limit set for 2010 (20 µg/m3) in all of the other cities monitored (Fig. 4.2c, 4.2d).
The annual arithmetic means of the sum of nitrogen oxides (NOx) ranged from 14.3 to 100.1 µg/m3 in 2003 (Fig. 4.2f). As in previous years, the level of 80 µg/m3 (used as a comparative value) was exceeded in some Prague districts (Prague 1: 88.7 µg/m3, Prague 5: 100.1 µg/m3). The highest 24-hour mean levels were recorded in Prague 5 with heavy traffic (37 % of results over 100 µg/m3), Prague 8 (21.3 % of results over 100 µg/m3) and Prague 9 (21.6 % of results over 100 µg/m3) where the level of 300 µg/m3 was exceeded 7 times. The annual weighted arithmetic mean for the Prague conurbation is 67.7 µg/m3 on average. The lowest annual arithmetic mean, i.e. 14.3 µg/m3, was recorded in Příbram.
Concentrations of nitrogen dioxide (NO2) exceeded the limit of 40 µg/m3 only in some Prague districts (Prague 1: 47.2 µg/m3, Prague 5: 49.3 µg/m3, Prague 9: 40.2 µg/m3 and Prague 10: 46.4 µg/m3). The annual arithmetic means in most of the other cities monitored ranged from 19.3 to 37.1 µg/m3; a value under 20 µg/m3 was recorded in Brno (Fig. 4.2g). The value of 50 µg/m3 was most frequently, i.e. 114 times, exceeded in Prague 5. The annual mean concentrations have been increasing gradually, the statistical analysis proved an increasing trend in most of the cities within 1996–2003.
The measurement results confirm long-term low or stable concentrations of carbon monoxide (CO). As in previous years, high CO levels persist in heavy traffic areas in Prague. Levels over 5,000 µg/m3 were recorded for 11 days in Prague 10 and for 6 days in Prague 8 where the annual mean level reached 2,784 µg/m3. The annual weighted arithmetic mean for the Prague conurbation is 1,600 µg/m3, the annual arithmetic means calculated for the other localities monitored range from 216 to 671 µg/m3.
Outdoor air ground ozone concentrations have been monitored in 15 cities. The annual arithmetic means ranged between 33.3 µg/m3 and 64.4 µg/m3 (Fig. 4.2h). Twenty-four-hour concentrations exceeded 120 µg/m3 only in isolated instances, with the exception of Žďár nad Sázavou and Sokolov (with background stations). In 2003, no ozone episode (exceedance of the hourly value of 180 µg/m3) was recorded at the Public Health Service stations.
4.4.1 Metals in suspended particulate matter
The mass concentrations of selected metals were obtained by analysis of 14-day-cumulative samples of particulate matter. Air pollution with the elements monitored between 1995 and 2003 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 particulate matter can be described as follows:
Arsenic
The annual arithmetic means of As concentrations in 2003 ranged
from 0.001 µg/m3 to 0.004 µg/m3 (Fig. 4.6a).
Higher concentrations were recorded in Ostrava (0.00656 µg/m3)
where the annual concentration limit (0.006 µg/m3)
was exceeded. Half of 32 monitored cities showed slightly higher annual arithmetic
means in 2003 compared to 2002.
Cadmium
The annual concentration limit (0.005 µg/m3) was not exceeded in
any of the cities monitored. However, the highest mean annual level recorded
in Příbram (0.0048 µg/m3) is close to this limit. The annual arithmetic
means in most monitored cities are lower than 0.001 µg/m3 with the lowest
values recorded in Most (0.00008 µg/m3) and Klatovy
(0.00012 µg/m3) (Fig. 4.6b).
Chromium
No annual concentration limit was established for chromium. 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 (Cr+III plus Cr+VI). The
annual arithmetic mean concentrations of total chromium ranged from 0.0007 µg/m3
in Svitavy to 0.0262 µg/m3 in Prague 8. In most of the cities monitored,
the level of 0.005 µg/m3 was not exceeded (Fig. 4.6c).
Nickel
Sixteen cities were included in the analysis of Ni concentrations
(České Budějovice, Ústí nad Labem, Praha 10, Ostrava, Most, Karviná, Klatovy,
Plzeň, Ústí n. Orlicí, Kolín, Žďár n. Sázavou, Sokolov, Svitavy, Olomouc,
Havlíčkův Brod and Hodonín). The annual arithmetic means of concentrations
ranged from 0.0007 µg/m3 in Olomouc to 0.0113 µg/m3 in Most. The concentration
limit (0.02 µg/m3) was not exceeded in any of the cities
(Fig. 4.6d).
Lead
The annual concentration limit of 0.5 µg/m3 was not exceeded in any
of the 32 localities monitored (25 cities and 7 Prague districts) in 2003
(Fig. 4.6f). The highest annual concentration of lead was recorded in Příbram
(0.062 µg/m3) and the lowest level was found in Klatovy (0.0011 µg/m3).
Very good conformity between the annual arithmetic mean and the annual geometric
mean in most localities is suggestive of relative stability and homogeneity
of the concentrations recorded, without major seasonal, climatic or other
oscillations. Higher differences in the annual arithmetic and geometric
means were reported only in Příbram and Karviná. Long-term lead concentrations
in air show a downward trend in most cities, decreasing even by 80 % between
1998 and 2003. Fig. 4.6g clearly illustrates decrease in lead concentrations
in air of the monitored cities.
Manganese
The annual arithmetic means of concentrations ranged from 0.029
µg/m3 to 0.0028 µg/m3 in 2003 (Fig. 4.6e).
Higher concentrations were recorded
in Ústí n. Labem (0.6103 µg/m3) and Prague 8 (0.0733 µg/m3);
in Ústí n. Labem where the annual arithmetic mean exceeded the WHO recommended value of
0.15 µg/m3, the data were obtained from a station located in an industrially
polluted area. The lowest annual arithmetic mean was recorded in Klatovy
(0.0006 µg/m3).
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, at one measuring station per city; therefore the results obtained are not representative of the situation in the city as a whole.
4.5.1 Polycyclic aromatic hydrocarbons
In 2003, 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). 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 was exceeded in most of the cities monitored in 2003 (Fig. 4.5a). The highest burden from benzo[a]pyrene was found in Ostrava with an annual mean concentration of 7.8 ng/m3 and Karviná with 6.2 ng/m3. In winter, mean 24-hour concentrations higher than 40 ng/m3 were recorded at these stations on some days. The annual limit was also markedly exceeded in Prague 10 (2.5 ng/m3), Ústí n. Labem (2.1 ng/m3) and Hradec Králové (1.5 ng/m3). The annual mean concentrations in Plzeň and Žďár nad Sázavou were just below the limit and the lowest concentration was recorded in Brno.
The annual arithmetic means of benzo[a]anthracene (Fig. 4.5a) varied widely from 0.6 ng/m3 in Brno to 11.0 ng/m3 in Karviná where the reference concentration of 10 ng/m3 recommended as the highest allowable was exceeded. Higher contamination just below the reference concentration was recorded in Ostrava (9.2 ng/m3) while in the other localities, the contamination level was lower than one-third of the reference concentration.
The annual mean phenanthrene levels did not exceed the reference concentration of 1,000 ng/m3 in any of the cities monitored.
The total annual mean PAHs concentration expressed as the PAHs sum was highest in Karviná (Fig. 4.5a) being two to six times higher than in the other localities monitored. The PAHs sum 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 TEQ BaP. The following toxic equivalent factors (TEFs) pursuant to the US EPA were used for calculation of TEQ:
Converting TEQ BaP 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 2003 the highest carcinogenic potential was found in these two cities with annual means of 11.4 ng/m3 and 10.6 ng/m3, respectively. The values in Prague, Hradec Králové and Ústí nad Labem varied between 3 and 4 ng/m3 and the lowest value (below 1 ng/m3) was recorded in Brno. The mean annual BaP TEQ values in different cities over the period from 1997 to 2003 are shown in Fig. 4.5c.
The reference concentration of benzo[a]anthracene was exceeded only in Karviná. In contrast, the annual limit for benzo[a]pyrene was exceeded at all stations at least once over the period monitored. Throughout the whole monitoring period, the mean annual concentrations did not fall below the limit in Prague and Ústí n. Labem and regularly exceeded it several times in Ostrava and Karviná. Fig. 4.5b shows the concentration ranges of benzo[a]anthracene and benzo[a]pyrene in 1997–2003.
4.5.2 Volatile organic compounds
In 2003, volatile organic compounds (VOCs) in outdoor air were monitored at 11 stations operated by the Public Health Service and Czech Hydrometeorological Institute. At half of measuring stations operated by the Public Health Service, forty-two organic compounds were followed up (pursuant to US EPA TO – 14); nevertheless, only twenty-three of them were taken into account since the remaining ones were mostly present in concentrations below the respective detection limits. The remaining stations operated by the Hydrometeorological Institute monitor only benzene, toluene and sum of xylenes. Winter sampling was carried out on every sixth day, while from April to September, outdoor air samples were collected on every twelfth day.
An annual concentration limit of 5 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, sum of dichlorobenzenes).
Fig. 4.4a shows the annual mean benzene concentrations in 2000 to 2003. In 2003, the situation worsened: the limit for benzene was exceeded for the first time since 1999, in Ostrava (7.6 µg/m3) and Karviná (5.1 µg/m3). The annual mean benzene concentration was just below the limit in Hradec Králové (4.8 µg/m3), reaching 4.0 µg/m3 in Most and ranging between 2 and 3.5 µg/m3 in most other localities. The lowest concentration was recorded at the new Czech Hydrometeorological Institute station in Liberec (1.5 µg/m3).
Any of the reference VOC concentrations was not exceeded in any of the localities monitored. Fig. 4.4b shows annual mean concentrations of toluene and sum of xylenes. Toluene concentrations in most localities ranged between 4 and 7 µg/m3, lower values being recorded at two stations operated by the Czech Hydrometeorological Institute in Prague 4 and Liberec. In contrast, annual mean concentrations of sum of xylenes varied widely from 1.3 µg/m3 in Prague 4 to 8.9 µg/m3 in Most.
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 pollutants listed in Government Order No. 350/2002. The AQI takes into account annual arithmetic means of concentrations of SO2, NO2, PM10, As, Cd, Pb, benzene and BaP. AQIs were calculated for two groups of localities – group 1 of 20 localities where common pollutants are monitored and group 2 of 8 localities with additional monitoring of polycyclic aromatic hydrocarbons.
The AQI values in group 1 range from class 1 – clean atmosphere (Klatovy, České Budějovice and Havlíčkův Brod) to class 3 – moderately polluted atmosphere (Prague 2 and Prague 9). The PM10 limit is most frequently exceeded in group 1. The AQI values are shown in Fig. 4.7a.
In group 2, Žďár n. Sázavou, Hradec Králové, Plzeň and Brno fall into class 2 (acceptable atmosphere), Prague 10 and Ústí n. Labem into class 3 (moderately polluted atmosphere), and Ostrava and Karviná into class 4 (polluted atmosphere). The AQI values are comparable to those of 2002 with the benzo[a]pyrene and PM10 limits most markedly exceeded in Prague 10, Ostrava and Karviná, and the benzene limit most markedly exceeded in Ostrava and Karviná. The AQI values are shown in Fig. 4.7b.
4.6.2 Exposure to pollutants from ambient air
The effect of air pollution on health depends on the concentration of air pollutants, duration of exposure to pollutants and other factors such as 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 depending on 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 “supply” stratified e.g. at limit concentration intervals.
The evaluation 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. 4.3.
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 2003. 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, 30 % of the population monitored are long-term exposed to concentrations under 27 µg/m3 and 62 % of the population are exposed to concentrations between 27–40 µg/m3.
The population exposure to suspended PM10 continues to be of concern. The criteria established by Government Order No. 350/2002 were exceeded for 83 % of the population monitored in 2003. Exposure may be characterized as long-term, with slowly increasing mean values. The share of the population living in the localities where the concentration limit was exceeded, is rising for the period 2000 to 2003, most significantly in 2003, i.e. by 26 % compared to 2002. As many as 99 % of the population monitored are exposed to annual PM10 arithmetic mean values of over 20 µg/m3 (target limit by 2010).
4.7 Indoor air pollution
The project INDOOR focused on indoor air quality measurement and conducted in 2003 in 5 cities, i.e. Plzeň, Brno, Hradec Králové, Karviná, and Ostrava, had the following objectives:
4.7.1 Selection of dwellings
In phase 1, 1,250 dwellings, i.e. 250 dwellings per city, were randomly selected by the Czech Statistical Office from those meeting the enrolment criteria. A questionnaire investigation followed, focused on basic data on each household member, his/her daily routine, housing style and lifestyle. The overall questionnaire returnability was 55 %, with the highest rate (78 %) in Hradec Králové and the lowest rate (38 %) in Plzeň.
In phase 2, 100 dwellings, i.e. 20 dwellings per city, were randomly selected from the set of consenting respondents’ dwellings for indoor air quality measurement.
4.7.2 Parameters monitored
The following parameters were monitored in all dwellings selected:
About half of the dwellings were sampled for identification of organic compounds in air.
The system of measurements and data processing was fully compliant with the QA/QC requirements and was based on the use of standard operating procedures (SOPs) for sampling analytic procedures, comparative measurements, measuring protocols, extreme data validation, etc.
4.7.3 Measurement results
From June 2003 to February 2004, measurements were carried out in 90 dwellings, in 40 out of these dwellings in the non-heating season (from June to September) and in 50 out of these dwellings in the heating season (from November to February) to detect seasonal trends. The measurements were always performed in the largest room and in the kitchen.
One-hour limits set up by Decree No. 6/2003 of the Ministry of Health of the Czech Republic which specifies limits for chemical, physical and biological indicators in the indoor environment for some buildings (the Decree does not apply to dwellings) were used as comparative figures in evaluation of the measurement results obtained. Descriptive characteristics of the values obtained in 3-hour measurement of indoor air quality in dwellings are given in Tab. 4.1 and 4.2 and Fig. 4.8a and 4.8b.
The indoor air quality measurement results obtained in 5 cities showed the following:
Very low concentrations were found in case of styrene and tetrachloroetylene, more than 50 % of the samplings were under the limit of quantification.
4.7.4 VOCs qualitative determination
VOCs identification but not quantification was also part of the indoor air project. Indoor air was sampled for qualitative analysis in the largest rooms of 40 dwellings. In total, 93 VOCs including mainly aliphatic hydrocarbons and their derivatives, aromatic hydrocarbons and their derivatives, oxygenated organic compounds and terpenes were detected. The detection rates of selected VOCs in the monitored dwellings are shown in Tab. 4.3. The VOCs found at least in 4 dwellings, i.e. in 10 % of the dwellings monitored, are presented.
Apart from the standard VOCs listed in section 4.7.3, the following five chemicals which pose potential health risk were identified: butyl acetate, benzaldehyde, phenol, ethyl acetate and naphtalene with butyl acetate and naphtalene being the most frequently found (in 4 and 12 dwellings, respectively). Since quantitative determination was not performed, concentrations of these compounds are not known. The high reference concentration and lowest observed adverse effect level (LOAEL) for butyl acetate rather suggest that this compound is present in indoor air at safe concentrations. As for naphtalene, quantitative determination would be needed to eliminate health risk to lungs and nasal mucous membrane signalled by the relatively low reference concentration (IRIS EPA: 3 µg/m3).
4.8 Partial conclusions
The incidence rate of treated acute respiratory diseases (ARD) in 2003 is similar to those in previous years. The monthly ARD incidence rates varied widely in the cities monitored from units to hundreds of cases per 1,000 population of a given age group. The highest morbidity is typically reported in the age group 1 to 5 years. Upper respiratory tract infections were most frequent (76 %) among the ARD monitored.
Ambient air quality slightly declined in 2003 compared to 2002 due to increasing traffic pollution. The pollutants released into air are mainly suspended PM10, NO2, benzene and benzo[a]pyrene, the limits for which were exceeded. The increase in arsenic pollution of air is attributable to revival of the use of coal for home heating. The most important changes in 2003 were found in suspended PM10 with the annual limit of 40 µg/m3 being exceeded in 14 cities (83 % of the population monitored) and the target limit of 20 µg/m3 set up for 2010 being exceeded in all of the cities monitored. The statistical analysis showed the increasing trend in NO2 pollution in most of the cities. Mean concentrations of benzo[a]pyrene exceeded the limit at most of the measuring stations; the annual means of benzene concentration exceeded the limit in Ostrava and Karviná for the first time within the five-year monitoring period.
Apart from industrial cities such as Příbram, Karviná, Ústí nad Labem, etc., air pollution poses problems for large conurbations (Prague, Ostrava) with the limits exceeded for multiple air quality parameters and heavy traffic hot spots (Plzeň, Děčín and Hradec Králové) as illustrated by classification of these cities by Air Quality Index.
The indoor air quality measurements that continued in 2003 in residential dwellings of the commonest size in the Czech Republic showed the following: in most dwellings, higher indoor temperature and lower relative humidity than recommended were found. Mean concentrations of suspended PM10 are close to 50 µg/m3. Concentrations over 200 µg/m3 were recorded exceptionally. Nevertheless, these extreme values can be explained by extraordinary factors such as decorating or repairs in the house or the flat user’s lifestyle (smoking). Higher concentrations of nitrogen dioxide were not found in spite of the wide use of gas heating: NO2 is not a problematic factor. In contrast, high concentrations of formaldehyde were relatively frequently found, with the mean value of 60 µg/m3 being exceeded for 13 % of rooms and 14 % of kitchens. The concentrations of VOCs except for benzene were generally low. The 3-h mean concentration was 6 µg/m3 but high to health hazardous concentrations were found in isolated instances. Qualitative analyses identified the presence of many organic compounds in indoor air. Potential health risk is suspected by five of them with butyl acetate and naphtalene being most frequently found.
Tab. 4.1 Relative humidity, temperature, NO2, PM10 and formaldehyde concentrations in indoor air
|
Humidity |
Temperature |
NO2 |
PM10 |
Formaldehyde |
|||||
room |
kitchen |
room |
kitchen |
room |
kitchen |
room |
kitchen |
room |
kitchen |
|
Maximum |
62.0 |
66.0 |
28.0 |
29.0 |
76.2 |
121.0 |
843.0 |
952.0 |
199.0 |
214.0 |
Minimum |
25.0 |
25.0 |
15.0 |
18.2 |
u.l. |
u.l. |
7.0 |
6.3 |
u.l. |
u.l. |
Arithmetic mean |
43.7 |
44.5 |
22.9 |
23.0 |
15.1 |
19.7 |
42.0 |
45.2 |
36.4 |
35.0 |
Median |
44.6 |
44.2 |
23.0 |
22.8 |
12.6 |
15.1 |
23.8 |
25.3 |
29.8 |
23.5 |
95th percentile |
58.5 |
60.4 |
27.2 |
27.3 |
35.3 |
43.5 |
84.9 |
97.4 |
77.2 |
79.5 |
1-h limit |
30–55 |
19–22 |
100 |
150 |
60 |
Note: u.l. – under the limit of quantification
Tab. 4.2 Concentration of volatile organic compounds – room (µg/m3)
|
Benzene |
Toluene |
Xylenes |
Styrene |
Tetrachloroetylene |
Maximum |
230.0 |
536.0 |
290.0 |
8.1 |
64.4 |
Minimum |
u.l. |
u.l. |
u.l. |
u.l. |
u.l. |
Arithmetic mean |
6.0 |
31.2 |
18.7 |
* |
* |
Median |
2.4 |
11.4 |
6.2 |
* |
* |
95th percentile |
8.4 |
73.3 |
82.1 |
4.0 |
17.1 |
1-h limit |
7 |
300 |
200 |
40 |
150 |
Note: u.l. – under the limit of quantification
* values under the limit of quantification in more than 50 % measurements
Tab. 4.3 Qualitative analysis: frequency of identified VOCs in the dwellings
VOC |
Frequency of VOCs |
VOC |
Frequency of VOCs |
||
Number |
% |
Number |
% |
||
Acetone |
42 |
100.0 |
Izobutane |
19 |
45.2 |
Benzene |
42 |
100.0 |
Pinene |
16 |
38.1 |
Ethanol |
42 |
100.0 |
Dekane |
15 |
35.7 |
Propane |
42 |
100.0 |
Undecane |
15 |
35.7 |
Toluene |
42 |
100.0 |
Octane |
14 |
33.3 |
Izoprene |
41 |
97.6 |
Heptane |
12 |
28.6 |
Xylenes |
38 |
90.5 |
Methylhexane |
12 |
28.6 |
Ethylbenzene |
37 |
88.1 |
Naphtalene |
12 |
28.6 |
Propene |
37 |
88.1 |
Der.hexane |
9 |
21.4 |
Limonene |
36 |
85.7 |
Dodecane |
9 |
21.4 |
Buthanole |
35 |
83.3 |
Hexanal |
9 |
21.4 |
Nonane |
32 |
76.2 |
Ethyltoluene |
6 |
14.3 |
Trimethylbenzene |
24 |
57.1 |
Styrene |
6 |
14.3 |
Butane |
21 |
50.0 |
Carene |
5 |
11.9 |
Der.butane |
21 |
50.0 |
Butylacetate |
4 |
9.5 |
Der.pentane |
21 |
50.0 |
|
|
|
Note: Bold are routinely monitored VOCs.