Industrial substances

The main sources of anthropogenic air pollution are:

• burning of fossil fuels
• transportation by automobiles
• production processes in the petrochemical and metallurgical industry
• forest fires and volcanic activity

Many industrial countries have the maximum allowed concentration of selected pollutants in the atmosphere regulations.

Smog formation

Winter smog

• typical for the winter period, when it heats up intensively (in heating plants, households). It occurs during the period of inversion weather. SThe flue gases remain in the ground layer of the atmosphere.

Summer (ozone smog)

• it is created especially in cities with heavy car traffic during hot summer leather with intense sunlight
• the main cause is exhaust gases, which contain nitrogen oxides and residues of organic compounds.
• Ozone is formed under these conditions

Harmful compounds arising in combustion processes (Horák et al. 2004)

Combustion product	Conditions affecting creation	Effect
CO2	It is always created.	It is non-toxic, a common part of the atmosphere, but affects the greenhouse effect.
H2O	The formation depends on the hydrogen content in the fuel.	A harmless component of fuel.
CO	The content depends on the excess air and the level of control of the combustion process.	It binds to blood dye and reduces the blood's ability to carry oxygen, it is a harmful component of exhaust gases.
NOx	They are formed by the reaction of atmospheric nitrogen with oxygen, the amount formed depends on the temperature and combustion mode. At high temperature, more of them are formed.	They are an irritating component of exhaust gases, they are a component causing the formation of winter and summer smog. In the air, they change to nitric acid and are a component of acid rain.
SO2	It is formed from sulfur compounds present in the fuel, practically all the sulfur in the fuel passes into the flue gas.	It is an irritating component of flue gas, it quickly converts to sulfuric acid in the air, one of the components causing the formation of winter smog. It is the main component of acid rain.
Fuel residues	Remains of unburned and incompletely burned organic compounds.	They have irritating properties. They are components causing the formation of winter and summer smog.
Dust particles	Formed by ash and the remains of unburned substances, their formation depends on the fuel used.	They have irritating effects. It contributes to the formation of winter and summer smog. Sometimes they contain carcinogenic condensed PAHs.

Persistent Organic Pollutants (POPs)

Persistent organic pollutants are substances that enter the environment only as a result of human activity, either intentionally (e.g. pesticides) or as an escape' from anthropogenic activities (production, transport, transport, chemical accidents, etc.). The main reason for their monitoring is proven wide spectrum of toxic effects of these substances. They are highly resistant to degradation (chemical and biological), have non-polar molecules that accumulate in fatty tissues. Therefore their strong penetration into food chains occurs.

this concerns:

• polycyclic aromatic hydrocarbons (PAH)
• polychlorinated biphenyls (PCB)
• organophosphate and carbamate pesticides (OCP)
• polychlorinated dibenzo-p-dioxins (PCDD)
• polychlorodibenzofurans (PCDF)

Polycyclic aromatic hydrocarbons (PAHs)

• They are released during an imperfect combustion process
• They enter the environment during energy production, waste incineration, road transport, oil cracking, aluminum production, coke, asphalt cement production, metallurgy, refineries, crematoria, fires, volcanic activity during smoking, meat smoking, etc.
• PAH molecules are made up of two or more condensed benzene nuclei with a conjugated double bond system
• They are proven carcinogens
• By monitoring PAHs in ecosystems, it was found that 10% of the atmospheric amount of PAHs enters the soil through direct fall, 45% is captured in the form of vegetation fallout, 5% is deposited in water bodies, the rest is subject to chemical transformation in the atmosphere

Polychlorinated biphenyls (PCBs)

• They are synthetically produced chemical substances, substituted with 2–10 atoms of chlorine
• In the 1970s, they became widespread as excellent non-flammable heat transfer fluids in transformers and heavy machinery, cooling oils in electrical equipment, polymer plasticizers, an additive in paints, coatings, printing inks...
• Poisoning can occur after long-term exposure to low doses
• With chronic exposure, they cause eczema and dermatitis
• PCBs are neurotoxic, hepatotoxic and suspected carcinogens
• The effect depends on the representation of individual PCBs in the mixture
• The toxicity of the individual representatives in the mixture varies considerably quantitatively
• Burning PCBs produces even more toxic substances:
  • polychlorinated dibenzo-p-dioxins (PCDDs)
  • dibenzofurans (PCDF)
• At present, the use of PCBs is only permitted for special applications, e.g. in mining facilities in a fire hazard environment
• the PCB concentration is monitored in milk, meat and butter

Organic Pesticides (OCPs)

• Substances or mixtures of substances used against organisms that damage cultivated plants, stocks of agricultural products, food products, industrial materials and products.
• The toxic effect of pesticides is based on an extreme toxic effect on the organism's metabolism.
• Divided into:
  • fungicides
  • insecticides
  • herbicides
  • other zooticides

DT (dichlorodiphenyltrichloeethane) organochlorine insecticide

• Discovered in 1939 by P. Müller - Nobel Prize
• Mass-spread insecticide after discovery (killing malaria-carrying mosquitoes, killing lice)
• In nature, it spreads with the water cycle, significantly volatilizes with water vapor
• Slow elimination (1% per day), still spreading through the food chain
• Slow degradability is dangerous for the environment
• Banned in the Czech Republic since 1974, its residues appeared in the organs of mammals
• In acute poisoning, the symptoms are excitation and dysfunction of the CNS, in oral poisoning , nausea, vomiting, disorientation, dizziness, weakness, convulsions, coma
• In case of chronic poisoning, it is neurotoxic and immunotoxic, it is a suspected carcinogen, although carcinogenicity has only been demonstrated in animals

Links

Related articles

• Ecotoxicology
• Metal contamination

Source

• MAREŠOVÁ, Věra. Ekotoxikologie. Kovy. Průmyslové látky [online]. [cit. 2012-03-13]. <https://el.lf1.cuni.cz/p79657934/>.