Environmental Problems
Lately an interest for the problems of estimation of atmosphere air
quality in the cities has increased. Firstly it should be connected with the
policy of environment protection, which is carried
out by developed countries. In 1992, II UN Conference on Environment protection
and development adopted the Declaration that enunciated principles of stable
development. In particular a strategy has been worked out on limitation and
reduction of carbon dioxide emission that can effect catastrophically on the
world climate. In these declarations and plans atmospheric air is considered a
resource, qualitative consumption of which should be guaranteed not just for
the present generation of human beings but for future generations as well.
Air pollution impact on
human health in the Sochi region
The problem of air pollution is tightly connected with the development
of industry, transport and energetic. Continuous process of coal, natural gas
and organic fuel burning aimed at obtaining electrical energy and heat, wide
spread of automobile transport, waste of chemical plants and metallurgical
works – all this leads to accumulation of different chemical compounds in the
atmosphere, which affect the atmosphere composition in a planetary scale. Waste
of nitric oxide, sulphur oxide and carbon oxide badly affect different
components of biosphere. Health of the urban population in big industrial
cities is aggravating because of air pollution. It has been found that air
pollution results in building and monuments destruction. Among natural factors
of air pollution there are volcanic activity and wind erosion, the latter is
partially connected with agricultural development: extension of land under
crops and soil destruction because of intensive exploitation.
Mathematical
modelling of the air quality is getting more and more effective instrument in
the analysis of atmosphere condition, due to the rapid development of
electronic computers and decrease in their cost, and also perfection of
mathematical models of transport of gaseous fluid- and solid dispersed components
of pollution. Systems of free air quality modelling have been created in big
cities such as Paris, Lisbon, Budapest, on a planetary scale, and over huge
regions as Western Europe or northern latitudes of Eurasia, as well as in small
towns such as Oxford or Cambridge, and even in the central street of London. We
have investigated the air pollution impact on the human health in the Sochi
region.
Sochi
stretches for 146 km along the Black See coast. Only its narrow seaside strip
of land, pressed by the main Caucasian mountain range against the Black Sea, is
within the city boundaries. The wind rose, the breeze circulation, and the
landscape make the air pollutants accumulate and precipitate locally in the
Sochi region.
Sochi
is a seaside climatic Russian resort, thus the air pollution can cause not only
the extreme environmental situation in the city, but also the economical
crises, because the residential districts as well as the resort institutions
are located in the actively polluted zones, rather close to the motorway. This
obviously affects the state of health of the Sochi residents.
The
link between the air pollution and human health in the Sochi area has been
established for several diseases as some form of cancer, and asthma. The
significant correlation of 0.869 was found between the asthma sickness rate of
children (asthma sick per thousand people in year) and the number of vehicles
in the Sochi region - see Figure 1.
The correlation of 0.8158 was found between the Sochi region residents and
the number of vehicles - see Figure 2.
Figure
1. Link between the asthma sickness rate of children (asthma sick per thousand
in year) and the number of vehicles in the Sochi region.
Figure
2. Link between the asthma sickness rate of residents (asthma sick per thousand
in year) and the number of vehicles in the Sochi region.
Air
pollutants turbulent transport in Central Sochi
The
Central Sochi part shown in Figure 3 has been considered as applied example to
estimate the air quality near the main streets. The computational square domain in the plane XZ intersects the main streets Kurortny
Avenue and Ordgonikidze Street
which are situated parallel to the Black Sea shoreline - see Figure 3.
The atmospheric boundary layer flow predominate in the summer daytime is the
breeze circulation. So, the wind direction is primary from the sea to the
mountains, perpendicular to the street lines.
The database of the meteorological parameters in
the Sochi region consists of the data set series for more then 100 years of the
routine daily observations. The topography of the Sochi region includes the
erosive relief and the rivers grid, the forest coverage, and the large
difference of altitudes from the Black Sea level up to greatest altitude of
3256 m in the Caucasus Mountains. In the urban domain there are numerous
buildings, that also it is necessary to take into consideration in the model of
the air pollution transport in the lower part of atmosphere. As it has been
established the main air pollution problem in this region is connected with the
motor transport emission. Therefore the process of turbulent diffusion of
traffic wastes is localised in the surface layer of atmosphere and greatly
depends on parameters of turbulence as well as on the condition of
stratification. Also the roughness of ground surface, including the artificial
roughness in a form of buildings, trees, etc is a very important factor in this
problem.
Figure 3. The computational domain chosen for
an estimation of the air pollutants turbulent transport is parallel to XZ plain, and intersects the main streets
in the wind direction.
The traffic flow and emission rate has been estimated for two main
streets: Kurortny Avenue and Ordgonikidze Street. In summer daytime the traffic
flow rate is about 1500 vehicles per hour for each of them in the cross section chosen for the air quality
modelling.
It's known the carbon oxide and NOx the main air pollutants,
which are dangerous for human. In the Central Sochi region the major souses of
emission of CO and NOx are the gasoline passenger cars (>95%). The normal
emission of CO is about 16 g/km in the urban region and about 30.4 g/km for the
cold start. Hence the mean value of CO emission rate has been estimated as 19
g/km.
Put
is the CO emission rate for one car, 
is the traffic
flow rate (=the number of cars going on the road cross section in the unit of
time). Then the total emission rate can be estimated as 
.
Figure 4. The
isolines of CO concentration normalized on MPC in the turbulent stable (right)
and unstable (left) stratified flow over the region with two parallel roads. Zones
of the CO concentration over MPC are darkened
Thus in the considered case the CO total emission rate is about 
. This value has been used to compute the local zone in which
the CO concentration is higher then the maximum permissible concentration.
The state sanitary standard adopted in Russia is the maximum permissible
concentration (MPC) that in the case of CO emission is defined as CMPC=5
mg/m3.
The isolines of CO concentration normalized on MPC are shown in Figure 4
for the stable (right) and unstable (left) stratification. The heat flux is
computed for the cloudless sunset time. The roughness length is estimated for
the urban landscape as r=1 m. Figure 4 shows that the dangerous zones of
CO concentration can be near the roads (about 20 m from the roadside) due to
the small value of the turbulent intensity in the evening time.
The turbulent transport of NO and NO2 has been calculated for the daytime and
evening time - see Figure 5. In this case the normal gasoline car emission rate
is about 2 g/km, and for the passenger diesel it can
Figure
5. The isolines of NOx concentration normalized on MPC in the
turbulent unstable (right) and stable (left) stratified flow over the region
with two parallel roads located as shown by the black pointers. Zones of NOx
concentration over MPC are darkened. In the black zones the NOx
concentration in two times higher then MPC
be
up to 12 g/km. Using the gasoline car emission rate the total emission rate of nitrogen
oxides for the Kurortny Avenue can be estimated as 
.
The maximum permissible concentrations for the nitrogen oxides is much less then for the carbon monoxide,
it's only CMPC =0.04
mg/m3 for NO2
, and CMPC = 0.06 mg/m3 for NO.
The turbulent transport data of NOx concentration normalized
on MPC computed for the day time (left) and evening time (right) are shown in
Figure 5.8. This data shows that the dangerous zones in the evening time occupy
the region which has the width about 300 m, and the height up to 6 m. Therefore
the dangerous zones of NOx
concentration can occupy the habitable buildings as
well as the kindergarten and musical school built near the considered roads
cross section. Thus the nitrogen oxides can be one of the human health damaging
factors in Sochi.
Turbulent transport of lead
aerosols in Central Sochi
The
lead aerosol is the most important damaging factor of the human health. The
leaded gasoline has been widely used in the Sochi region. The lead
concentration in the fuel dependent on the gasoline type varies from 170 up to
370 mg/l. The mean lead emission is estimated as 
mg/km. For the mean vehicle way per year about 30000 km it gives
approximately 1 kg of the lead aerosol emitted by one normal passenger car.
The
number of vehicles in the Sochi region has extremely grown in the last decade: from about 20000 in
1990 up to 100000 in 1999. The
lead aerosol emission averaged on 10 years interval is 60 ton/ year. The
total emission rate of lead aerosols for the Kurortny Avenue and Ordgonikidze
Street in the modeled cross section is estimated as 
mgs-1m-2.
As
it has been established in the numerical experiments the turbulent diffusion
parameters of the particles with diameter less then micron, 
, practically
independent on their diameter. The differences in the turbulent diffusion
parameters are essential for the lead aerosol particles with diameter 
. The heavy particles, which have the diameter in the range, 
are deposited
inside of the 200 m zone.
Figure 6.
Turbulent transport of the lead aerosol for the fixed meteorological condition:
Aerosol concentration is normalized on the turbulent concentration scale
computed for the fraction of aerosol particles, 
.
In the Sochi region in the end of 80's the
concentration of lead was higher then the MPC of lead in the air and in soil
near the main motorways. In the middle of 90's the environmental situation even
more deteriorated in connection with significant increasing of the air
pollutants emission. It has been established that the rise
of air pollutants emission
leads simultaneously to increase the sickness rate of respiratory diseases - see Figures 1,2. Therefore the local
administration has forbidden using the leaded fuel in the Sochi region in 1996.
In practice, however, the administrative measures on limitation of the air
pollutants emission are not extremely effective, because the total control of
exhaust gases is practically impossible to use.
References
Amirkhanov, M.M, Lukashina, N.S. & Trunev, A. P., Natural recreation resources, state of
environment and economical and legal status of coastal resorts, Publishing
House "Economics", Moscow, 207 p., 1997 (in Russian).
Lukashina, N.S. & Trunev, A. P., Principles
of Recreation Ecology and Natural Economics, Russian Academy of Sciences,
Sochi, 273 p., 1999 (in Russian).
Lukashina, N.S., Amirkhanov, M.M, Anisimov, V.I. & Trunev, A.P.,
Tourism and environmental degradation in Sochi, Russia, Annals
of Tourism Research, 23, pp.
654-665, 1996.
Trunev A. P. Theory
of Turbulence and Turbulent Transport in the Atmosphere. WIT Press, 2001.