Air Pollution Sources and Impacts

Project Guide: Dr. Tanuja NautiyalDepartment of ChemistrySubmitted By- Sonal and Suraj (Branch: EEE)

AIR POLLUTIONAir pollutionis the introduction of harmful substances including particulates and biological molecules into Earth's atmosphere. It may cause diseases, allergies or death in humans; it may also cause harm to other living organisms such as animals and food crops, and may damage the natural or built environment.

Air Pollution Sources and Impacts

Properties: Gas, colorless and odorless in low concentrations, but with irritating odor in high concentrations

Sources: Power plants, oil refineries, chemical plants, paper industry, ships main and auxiliary engines

Sulphur content in crude oil and fuel oils

a) Safety (installation and piping corrosion, poison potential) b) Operation (fluidized beds of catalysts may be contaminated from the presence of sulphur compounds) c) Environment (SOx emissions)

SOx and NOx pollution

Sulphur Oxides (SOx)

Impacts to human health

Short term exposure in high concentrations, might cause bronchoconstriction and increased asthma symptoms.

Long term exposure might cause serious respiratory problems and deteriorate existing cardiovascular illnesses

Nitrogen Oxides (x)

Very complex mechanism of formation, hundreds of chemical reactions occur

Main source of nitrogen is air combustion

Higher temperatures in cylinders lead to increase NOx emissions

95% is and about 5% NO2

CAUSES OF AIR POLLUTIONCombustion Engine ExhaustCars, trucks, jet airplanes and other combustion engine vehicles cause air pollution. The exhaust from these contains carbon monoxide, nitrous oxide and gaseous oxide. Factories, office buildings, homes and power-generating stations burn fossil fuels, which cause air pollution. The burning of oil and coal (fossil fuels) also contributes to smog. This air pollution destroys plants, damages buildings and creates oxidation on iron. Petroleum refineries release hydrocarbons and various particulates that pollute the air.Some power lines are not insulated and are high voltage. This creates air pollution

Pesticides used to kill indoor and outdoor pests, insecticides used to kill insects and herbicides use to kill weeds all cause air pollution.Radioactive fallout causes air pollution from the nuclear energy dispersed, which is a dust. Fertilizer DustDust from fertilizers used to help plants grow causes air pollution.Sick building syndrome (SBS) is the term used when there is indoor air pollution. This happens when there is not enough ventilation to disburse the toxic fumes from new carpet, paint and/or cleaning chemicals that are used indoors. Mold can also cause

EFFECTS OF AIR POLLUTIONAir Pollution Effects (1, 2) Reduced lung functioning Irritation of eyes, nose, mouth and throat Asthma attacks Respiratory symptoms such as coughing and wheezing Air Pollution in Philippines Photo: Jim D Stitch Increased respiratory disease such as bronchitis Reduced energy levels Headaches and dizziness Disruption of endocrine, reproductive and immune systems Neurobehavioral disorders Cardiovascular problems Cancer Premature death

GENERAL METHODS FOR CONTROL OF SO2 EMISSIONS Change to Low Sulfur Fuel Natural Gas Liquefied Natural Gas Low Sulfur Oil Low Sulfur Coal Use Desulfurized Coal and Oil Increase Effective Stack Height Build Tall Stacks Redistribution of Stack Gas Velocity Profile Modification of Plume Buoyancy

Background on Nitrogen Oxides There are seven known oxides of nitrogen : NO NO2 NO3 N2O N2O3 N2O4 N2O5 NO and NO2 are the most common of the seven oxides listed above. NOx released from stationary sources is of two types

General Methods For Control Of Nox Emissions NOx control can be achieved by: Fuel DenitrogenationCombustion ModificationModification of operating conditionsTail-end control equipmentSelective Catalytic ReductionSelective Non - Catalytic ReductionElectron Beam RadiationStaged Combustion

Cancer Risk EstimatesWe lack scientific data to determine a precise risk of cancer in the future from radiation exposure today.

We estimate the increase in the cancer incidence rate is about 0.17 percent per rem of radiation dose1; this is based on effects seen at high doses.

However, it may be impossible to demonstrate that additional cancers occur at low levels of radiation exposure since the normal incidence rate of cancer is plus or minus some natural variation

Radiation Effects on Embryo/FetusEmbryo/fetus is rapidly developing so is more sensitive to a possible radiation effect than an adult.Effects vary with amount of radiation and stage of development of the embryo/fetus.Principal effects are loss of pregnancy, malformations, and mental retardation.1Without radiation exposure, risk of spontaneous abortion is 15 percent.Without radiation exposure, risk of genetic disease is 11 percent.Without radiation exposure, risk of major malformation is 3 percent.Without radiation exposure, risk of growth retardation is 3 percent.Malformations are identical to those occurring naturally.More than 10 rem is required to increase the rate of malformations

Cell SensitivityActively dividing cells are most sensitive to radiation damage.Tissues that are more sensitive include skin, hair, early blood cells, and lining of the intestine.Tissues that are less sensitive include muscle, bone, brain, and connective tissue

Genetic EffectsGenetic mutations occur from incorrect repair of damaged chromosomes in egg or sperm cells.Ovaries can repair mild radiation damage.Genetic mutations may show up in future generations.Radiation-caused genetic mutations have been shown in animal studies at very high radiation doses (>25 rem).Radiation-caused genetic mutations have not been seen in exposed human populations

Radiation Damage to ChromosomesIndirect damageWater molecule is ionized, breaks apart, and forms OH free radical.OH free radical contains an unpaired electron in the outer shell and is highly reactive: Reacts with DNA.75 percent of radiation-caused DNA damage is due to OH free radical.

Direct damageDNA molecule is struck by radiation, ionized, resulting in damage

Types of Ionizing RadiationAlphaHelium nucleus (2 protons, 2 neutrons): +2 chargeBetaElectron: +1 or -1 chargeGamma and X-raysPhoton: 0 chargeNeutronNeutron: 0 charge

Sources of Ionizing RadiationRadioactive materials

Naturally occurring (uranium, carbon-14, ) Artificial (activated by neutrons from a reactor or accelerator beam)

Radiation Producing Machines

X-ray machines (characteristic, bremstrahlung) Accelerators (ion beams, neutrons, x-rays)

Exposure Prevention MethodsProtective clothing such as lab coats, gloves & safety glassesSelf-monitoring to reduce the spread of radioactive contamination