7.5 - Indoor Air Pollutants

Question 1

Developing vs developed countries

Answer 1

Developing:
- Developing countries use more subsistence fuels sucg as wood, manure, mcharcoal (biomass)
- these biomass fuels release CO, PM, NOx, VOCs (can also cause deforestation)
- often combusted indoors with poor ventilation, leading to high concentration
- Estimated 3 billion people globally cook with subsistence fuels, resulting in estimated 3.5-4.5 millin deaths annually

Developed:
- Developed nations use more commercial fuels (col, oil, natural gas) supplied by utilities
- typivally burned in losed, well ventilated furnaces, stoves, etc
- Major indoor pollutants in developed countries come from chemicals in producs, adhesives in furnature, cleaning supplies, insulation, lead paint

Question 2

PM and Asbestos

Answer 2

• Particulaes (PM) are a common indoor air polluant
  - Ex: smoke (from indoor biomass combustion or cigarettes), dust, and abestos
• Abestos is a long, silicate particle previously used in insulation (since been linked to lung cancer and asbestos
• phased out of use, but still remains in older buildings
  - not dangerous until insulation is disturbed and asbetos particles enter air and then respiratory tract
  - Should be removed by trained professionals with proper respiratory equiptment, ventialation in the area it’s being removed from, plastic to seal off area from rest of the building

Question 3

CO (Carbon Monoxide)

Answer 3

• CO is produced by incomplete combustion of basically any fuel
  - not all the fuel is combusted due to low O2 or temperature
• CO is aan asphyxiant: causes suffocation due to CO binding to hemoglobin in blood, displacing O2
• Lethal to humans in high concentration, especially with poor ventilation (odorless and colorless - hard to detect)
• developed nations: CO released into home by malfunctioning natural gas furnace ventilation
  - can be detected by carbon monozide detectors (similar to smoke detectors)
• Developing nations: CO emitted from indoor biomass combustion for heating/cooking

Question 4

VOCs (volatile organic compounds)

Answer 4

• Chemicals used in variety of home products that easily vaporize, entera ir, and irritate eyes, lungs, bronchioles
• Adhesives/sealats: chemicals used to glue carpet down, hold furniture together, seal panels
  - formaldehyde is a common adhesive in particle board and carpet glues (new carpet smell)
  -Ceaners: Common household cleaners and deoderizers such as febreeze
• Plastics and Fabrics: both can release VOCs themselves, orfrom adhesives used in production

Question 5

Radon Gas

Answer 5

• Radioactive gas released by decay of uranium naturally found in rocks underground (granite especially)
• usually enters homes through cracks in the foundation and then disperses up from basement/foundation through home
  - can also seep into groundwater sources and enter body through drinking water
• 2nd leading cause of ung cancer after smoking
  - EPA recommends testing homes with airborne Radon monitor
  - sealing cracks in foundation can prevent it from entering and increasing ventilation in the home can disperse if its detected

Question 6

Dust and Mold

Answer 6

• Natural indoor air pollutants that can worsen asthma, bronchitis, COPD, emphysema
• Dust settles in homes naturally, it is distributed by movement, entering air and then repsiratory tract
• Mold develops in areas that are dark and damp and aren’t well ventilated (under sinks/showers, behind panels in wals and ceiling)
  - black mold is a class of mold that reelases spores into air
  - especially harmful to resp system
  - can be removed by physically cleaning mold out and fixing the water leak or ventilation issue that lead to mold forming

Question 7

Lead

Answer 7

• Found in pain in old homes (EPA banned lead paint in 78)
• Paint chips off wals/windows and is eaten by small children (due to curiosity and sweet taste) or inhaled as dust
• lead water pipes can also release lead into drinking waer sources (as in flint) but its less common than lead paint
  - damages central nervous system of children due to smaller size and still developing brain
• Can be removed from home by stripping lead paint and replacing with non-lead based paint
• Lead water piped can bereplaced by cities with copper pipes