Air Pollution Overview

Air Pollution

• Air pollution occurs when harmful or excessive quantities of substances are introduced into Earth's atmosphere.
• Pollutants include gases (sulfur oxides, nitrogen oxides, carbon monoxide, hydrocarbons), particulate matter (smoke, dust, fumes, aerosols), and radioactive materials.
• Air pollution is a mixture of solid particles, liquid particles, and gases suspended in the air.
• Air pollution kills an estimated seven million people worldwide every year.
• WHO data shows that 9 out of 10 people breathe air containing high levels of pollutants.

Sources of Air Pollution

• Sources are categorized by location:
  • Stationary sources: These have a fixed location, including point sources (e.g., smoke stacks of power plants) and area sources (e.g., urban communities with industrialization). Fugitive sources are also categorized as stationary sources, and pollute by being carried by wind from locations like agricultural areas, dirt roads, and mines.
  • Mobile sources: Sources that move while emitting pollutants, such as automobiles, trucks, buses, ships, and trains.

Sources of Air Pollution Based on Origin

• Natural sources: Natural gas emissions, discharges during storms, pollens, microorganisms.
• Manmade sources: Transportation (motor vehicles, aircraft, railway engines), industrial processes (petroleum, steel, paper industries, power plants, mining), agriculture (pesticides, herbicides, agricultural burning), and other sources (solid waste, forest fires, nuclear explosions).

Primary Pollutants

• Emitted directly from sources.
• Examples include particulate matter (ash, smoke, dust, fumes, mist, spray), inorganic gases (sulfur dioxide, hydrogen sulfide, nitric oxide, ammonia, carbon monoxide, carbon dioxide, hydrogen fluoride), aromatic hydrocarbons, and radioactive compounds.

Secondary Pollutants

• Formed in the atmosphere through chemical interactions among primary pollutants and normal atmospheric constituents.
• Examples include sulfur trioxide, nitrogen dioxide, tropospheric ozone, aldehydes, ketones, various sulfate and nitrate salts.

What else causes air pollution?

• Ozone can be good or bad based on its location in the atmosphere
  • Good ozone in the upper atmosphere blocks harmful solar radiation.
  • Bad ozone near the ground is harmful and is created when sunlight reacts with chemicals (like from fossil fuels)

How Air Pollution Affects Earth's Climate

• Some pollutants reflect sunlight while others absorb it.
• Dark-colored particles absorb heat, increasing temperature.
• Light-colored particles reflect heat, decreasing temperature.

How Air Pollution Affects Human Health

• Pollutants: Particulate matter (PM 2.5, PM 10), Nitrogen oxide (NOx), Sulfur dioxide (SO2), Carbon monoxide (CO).
• Impacts: Breathing problems, asthma, lung cancer, chronic obstructive pulmonary and cardiovascular diseases, impact on liver and spleen, irritation of eyes, nose, and throat, cardiovascular diseases, headache and anxiety, irritation of eyes, nose, and throat, lung cancer, chronic obstructive pulmonary disorder, cardiovascular disease

Indoor Air Pollution

• Indoor air pollution comes extensively from cooking gas, heaters, fireplaces, wood or coal burning stoves, smoking, household products (detergents, waxes, polishes, air fresheners, pesticides, glues, paints, hair sprays, oven cleaners, permanent press fabrics, synthetic fibers).
• Cleaning activities like dusting and vacuum cleaning contribute to indoor pollution.
• Outdoor air pollution can also become indoor pollution, especially in older/leaky buildings.

Bangladesh Perspective

• High air pollution-related deaths.
• Reduction in GDP due to pollution.
• Major causes are brick kilns, vehicular emissions, and construction sites.
• Number of vehicles and brick kilns in Dhaka have increased from 2010 - 2018.
• Other significant sources of pollution from industrialization, urbanization and infrastructure construction.
• A huge amount of air pollution from industrial emissions, vehicle emissions, waste burning, solid particles (10 micrometres or smaller; PM10), and household use of solid fuel. The sources of the PM 10 includes brick kilns, cement, steel, and ceramic factories. 72% of the nation uses solid fuel for their households.

Legal and Policy Initiatives

• Bangladesh Environmental Conservation Act (1995) and Environment Conservation Rules (1997).
• Amendments in 2002, 2003, and 2010 on pollution regulations, restricting automobiles sales and production of harmful items . Also, regulations on vehicular exhaust emissions.
• The Brick Production and Brick Kiln Building Act (2013) and amendments in 2019. Promotion of using cleaner kiln technology.
• The Clean Air Act is needed. Air quality observation stations.
• Need more comprehensive and immediate government action.

How to Stop Air Pollution

• Recommendations included using public transport, walking, and bicycling.
• Supporting clean energy.
• Removing old vehicles.
• Promoting public awareness.
• Planting more trees and vegetation.
• Replacing processes that don't pollute the air.
• Prevent toxic substances from entering the air.

Climate Change

• Weather refers to current conditions (temperature, pressure, precipitation, winds).
• Climate is the average weather over long periods (years or decades).
• Climate change occurs when climate doesn't remain constant. A significant change depends on the underlying level of climate variability.
• Global warming refers to rising average temperatures due to increased greenhouse gases.
• Climate change is a broader term encompassing temperature and precipitation variations.

How Global Warming Works

• Natural Greenhouse Effect: Some heat is trapped by atmospheric gases (e.g., CO2, CH4), warming the Earth.
• Human Enhanced Greenhouse Effect: Increased human activities release more greenhouse gases, trapping more heat.

Major Greenhouse Gases

• Sources are primarily from anthropogenic activities.
• Examples include carbon dioxide, CFCs, methane, nitrous oxides, and ozone.

Global Greenhouse Gas Emissions

• Breakdown of emissions by gas type.
  • Carbon Dioxide is the largest emitter at 65%, followed by Forestry and land use.
• Breakdown of emissions by economic sector.
  • Electricity and Heat production is the largest at 25% followed by Agriculture, Forestry, and Other Land Use at 24%.

The Rise in Average Global Temperature

• Directly linked to the rise in concentration of CO2 and other GHGs in the atmosphere.
• 2016 was the warmest year on record, 1.1°C above pre-industrial levels.

Effects of Global Warming

• Changes in climate patterns.
• Increased temperature.
• Rising sea levels.
• Melting glaciers and ice caps.
• Changes in the biosphere (habitats, species, water supply).

Bangladesh's Vulnerability to Climate Change

• Most vulnerable country due to flat, low-lying topography.
• High population density.
• Dependence on sensitive sectors, particularly agriculture and fisheries.
• Poor infrastructure and socioeconomic conditions.

Past and Future Climate Change Scenarios in Bangladesh

• Past: Temperature increases, changes in rainfall patterns, cyclone frequency, sea level rise.
• Future: Increased temperature, increasing rainfall in certain areas, rising sea levels, extreme temperature and drought in the North and North-western regions by 2100.

Climate Change Impacts in Bangladesh

• Increased frequency and intensity of cyclones, larger flooding magnitudes.
• Spreading droughts.
• Erratic rainfall.
• Increasing riverbank and coastal erosion.
• Water logging and permanent inundation.

Hazards Bangladesh Faces

• Drought, cyclones, storm surges, floods, waterlogging, and bank erosion.

Adjusting to Climate Change

• Mitigation: Reducing greenhouse gas emissions and enhancing sinks (e.g., reforestation).
• Adaptation: Adjusting to climate change impacts.

Adaptation Measures for Specific Hazards

• Drought: Rice cultivation with minor irrigation, digging ponds for water reservoirs, using less water-consuming trees, More vegetation, Homestead Garden, Crop Diversification
• Flash Floods in Haor Areas: Crop diversification, Swamp vegetation plantation, Canal re-excavation.
• Coastal Areas: Cyclone shelter centers, climate-smart house design, salt-tolerant crops, afforestation.

Other Recommendations

• Be Energy-efficient: Use energy-efficient lightbulbs, encourage the use of solar, wind, and biomass power sources.
• Institutional Initiatives: support for research that develop salinity-tolerant rice species, other crops, and mangrove plantation techniques.
• Also investigate the NAPA measures from 2009 (Adaptation) into different sectoral policies of the government.