Graphic Yearbook

Tab. I.5 Brief characteristics, overview of major emission sources and major effects of ambient air pollutants

Pollutant and its sources	Health effects	Environmental effects
Suspended particles Primary particles are emitted directly as liquid or solid particles. Secondary particles are formed in the atmosphere during physical or chemical processes from their gaseous precursors SO₂, NO_x, VOC and NH₃ (Pöschl 2011; EEA 2013a). The largest anthropogenic sources in the CR: residential combustion, road transport, farm-level agricultural operations and transport of agricultural products and public electricity and heat production.	Aerosol particles cause a broad spectrum of effects on the cardiovascular and respiratory systems. They irritate the respiratory tract, impair defence mechanisms and facilitate infections, induce an inflammatory response in lung tissue, contribute to oxidative stress and thus to the progression of atherosclerosis, and affect the electrical activity of the heart; since 2013 they are listed among proven human carcinogens (IARC 2015). The effects depend on the size, shape and composition of particles. Short-term increases of daily PM₁₀ concentrations contribute to increasing total morbidity and mortality caused mainly by cardiovascular diseases, to the growth of the number of persons hospitalized due to respiratory tract diseases, increasing infant mortality and increasing the frequency of coughing and breathing problems, mainly in asthmatics (SZÚ 2015b). Long-term increased concentrations can result in reduced pulmonary function, increased morbidity due to respiratory tract diseases and increased incidence of chronic bronchitis symptoms and decreased lifespan, especially due to increased mortality of the elderly and sick due to cardiovascular and respiratory diseases, including lung cancer (SZÚ 2015b). No safe threshold concentration has so far been ascertained for the effects of airborne aerosol particles.	Suspended particles affect both animals and humans, affect plant growth and ecosystem processes, and may damage and tarnish buildings or decrease visibility (EEA 2013a).
Benzo[a]pyrene Benzo[a]pyrene, occurring in the atmosphere primarily bound to the particles, is a suitable marker of ambient air pollution caused by PAH. The reason is its stability and relatively constant contribution to carcinogenic activity of the mixture of PAH bound to the particles (EC 2001a).The major sources of benzo[a]pyrene in the Czech Republic are residential combustion and road transport (imperfect combustion).	PAH are a group of substances of which many have toxic mutagenic or carcinogenic properties, are endocrine disruptors (substances damaging the function of internal secretory glands) or are immunosuppressive. They affect foetal growth. Prenatal exposure to PAH is related to markedly lower birth weight (Choi et al. 2006) and probably also adversely affects the cognitive development of young children (Edwards et al. 2010). Benzo[a]pyren itself is classified as a proven human carcinogen (IARC 2012).	PAH can bioaccumulate and enter the food chain (Brookes et al. 2013, EEA 2013a).
Nitrogen oxides The term “nitrogen oxides” (NO_x) refers to nitric oxide (NO) and nitrogen dioxide (NO₂). More than 90 % of anthropogenic emissions of NO_x are represented by NO emissions. The major anthropogenic sources of NO_x in the Czech Republic are road transport, off-road vehicles and other machinery in agriculture and fishery and forestry, public electricity and heat production, stationary combustion in manufacturing industries, and construction (chemicals and other processes).	As concerns the impact on human health, the most significant nitrogen oxide is NO₂ (WHO 2006). NO2 can affect mainly the respiratory tract. The main effect of short-term exposure to high concentrations of NO₂ is increased reactiveness of the respiratory tract and ensuing worsened symptoms in people with asthma (Samet et al. 2000). Exposure to NO₂ impairs lung functions and increases the risk of respiratory diseases in children due to reduced immunity to infections (EEA 2013a, Peel et al. 2005). It is also mentioned in connection with total mortality caused by cardiovascular and respiratory conditions (Stieb et al. 2003, Samoli et al. 2003). It is difficult to separate the effects of NO₂ from those of other simultaneously acting substances, mainly aerosols (WHO 2006), hydrocarbons, ozone, among others (Brauer et al. 2002).	NO_x contribute to acidification and eutrophication of soil and water. High NO_x concentrations can lead to damage to plants. NO_x act as precursors of ground-level ozone and particulate matter (EEA 2013a, Brookes et al. 2013).
Ground-level ozone Ozone (O₃) is a secondary pollutant without its own emission source; it is formed as a part of photochemical smog. It is formed under the influence of solar radiation during a series of reactions mainly between NO_x, VOC and oxygen. (EEA 2013a). Ozone can be transported over long distances, accumulate and reach high concentrations far from its place of origin (Brookes et al. 2013).	The main effect of ozone on the human organisms is irritative. It irritates the conjunctiva, nasal mucous membranes and bronchi. Short-term studies show that O3 concentrations may have adverse effects on pulmonary function leading to lung inflammation and respiratory problems (EEA 2013a). Higher concentrations cause irritation-induced narrowing of the respiratory tract and breathlessness. More sensitive to ozone are people with chronic obstructive diseases of the lungs and asthma patients. Higher concentrations of ozone are purportedly associated with increased mortality during the day (WHO 2006).	Ground-level ozone damages vegetation, impairs plant growth and decreases crop yields; it can damage forest ecosystems and reduce biodiversity (EEA 2013a).
Benzene Benzene is present in the atmosphere mainly due to anthropogenic activities. The largest source of benzene emissions is represented by incomplete combustion of fuels used by vehicles. Other sources are domestic heating, oil refining, and the handling, distribution and storage of petrol (EEA 2013a).	Benzene ranks among human carcinogens (IARC 2014). At high concentrations, it can have haematotoxic, genotoxic and immunotoxic effects (SZÚ 2015a).	Benzene can bioaccumulate; it can damage leaves of agricultural crops and kill plants (EEA 2013a).
Lead Most lead present in the atmosphere is released from anthropogenic emission sources. The main sources in the Czech Republic are stationary combustion in manufacturing industries and construction (iron and steel and other), public electricity and heat production, and iron and steel production.	Long-term exposure is harmful to the biosynthesis of haem, the nervous system and blood pressure in humans. Exposure to lead poses risks to developing foeti; it may negatively influence brain development and, consequently, mental development, (Černá et al. 2011; EEA 2013a). As concerns its carcinogenic effects, lead is classified within group 2B – possibly carcinogenic to humans (IARC 2014).	Lead can accumulate in the bodies of organisms (bioaccumulation) such as fish and can enter the food chain (Brookes et al. 2013, EEA 2013a).
Cadmium Cadmium is bound mainly to the particles with aerodynamic diameter of up to 2.5 μm (EC 2001b). The main sources in the Czech Republic are public electricity and heat production, iron and steel production, and stationary combustion in manufacturing industries and construction (iron and steel, chemicals and other).	Long-term exposure to cadmium affects the function of kidneys. It can also have negative impacts on the respiratory tract; the effects of cadmium exposure also include lung cancer (WHO 2000).	Cadmium can bioaccumulate (EEA 2013a).
Arsenic Arsenic occurs largely in particles with aerodynamic diameter up to 2.5 µm (EC 2001b). The main sources in the Czech Republic are public electricity and heat production, residential combustion, and stationary combustion in manufacturing industries and construction (other).	High concentrations affect the nervous system (SZÚ 2015a). Lung cancer is considered to be the critical effect following the long-term inhalation (EC 2001b; WHO 2000).	Arsenic can bioaccumulate; it reduces plant growth and crop yields from soils containing arsenic (EEA 2013a).
Nickel Nickel is found in particles in the form of several chemical compounds with various levels of toxicity to humans and ecosystems. The main sources in the Czech Republic are public electricity and heat production, and stationary combustion in manufacturing industries and construction (chemicals, iron and steel and other).	Nickel can affect the respiratory and immune systems in humans (WHO 2000, EEA 2013a). Nickel compounds are classified as proven human carcinogens; metallic nickel and its alloys are classified as possibly carcinogenic to humans (IARC 2014).	Nickel may cause the pollution of soil and water.
Sulphur dioxide Sulphur dioxide (SO₂) is emitted into the atmosphere during the combustion of sulphur-containing fuels. The main sources in the Czech Republic are public electricity and heat production, and residential combustion.	SO₂ causes irritation of the eyes and respiratory tract. High SO₂ concentrations can lead to respiratory problems. Inflammation of the respiratory tract causes coughing, mucus secretion, aggravation of asthma and chronic bronchitis, and makes people more prone to infections of the respiratory tract. Those suffering from asthma and chronic lung disease are the most sensitive towards SO₂ exposure (EC 1997b; WHO 2014).	SO₂ contributes to acidification of the environment. It also contributes to the formation of secondary suspended particles with a proven negative impact on human health (EEA 2013a).
Carbon monoxide Carbon monoxide (CO) is a gas emitted due to incomplete combustion of fossil fuels. The largest sources of CO emissions in the Czech Republic are residential combustion, road transport, steel and stationary combustion in manufacturing industries and construction (iron and steel), and iron and steel production.	CO binds to haemoglobin more strongly than oxygen and thus reduces the oxygen-carrying capacity of blood. The first subjective symptoms of poisoning are headaches followed by impaired coordination and reduced awareness. Those suffering from cardiovascular disease are the most sensitive towards CO exposure (EEA 2013a). Toxic effects of CO become evident in organs and tissues with high oxygen consumption such as the brain, the heart and skeletal muscles. It is also dangerous to developing foeti (WHO 2000).	CO can contribute to the formation of ground-level ozone (EEA 2013a, Brookes et al. 2013).