indoor air pollution

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  • Indoor Air Pollution..

  • Indoor Air Quality : O2, CO2 in appropriate concentration : gas, radioactive substances, vapor,

  • Indoor Air pollutantsAeroallergensCommon air pollutants: particulate matters, ozone, NO2, SO2Others: CO, CO2, cigarette smoking, volatile organic compounds (VOC)Cancer-induced pollutants: radon, asbestos, formaldehydeBioaerosols: bacteria, virus, mold

  • Indoor air quality ..

  • AeroallergensAllergens: substances that stimulate the production of IgE in genetically disposed individuals Most allergens are proteins ranging in MW. from 5-100 KilodaltonAeroallergens are airborne particles that induce allergic reactions in sensitized subjects and can cause respiratory, cutaneous, or conjunctival allergyAeroallergens include- Pollens- Fungal spores- insect and mite feces- animal danders- Dusts

  • AeroallergensIndoor aeroallergens- House dust mites: Dermatophagoides pteronyssinus, D.farinae- insect: cockroach (American, German cockroach)- Animal danders: cat, dog- Rodents: mouse, rats- Fungus: Penicillium, Aspergillus, Cladosporium

  • From 9 studies in AR, asthmatic Thai patients

  • House Dust mites (HDM, ) 8 0.1 1 mm. Major allergens: group I allergen Life cycle 2 monthsMite fecal pellets size 10-35 m ()

  • House dust mites Exposure to Group I antigen > 2 microgram/gram dust -> stimulate specific IgE production (sensitization threshold)Exposure to Group I antigen > 10 microgram/gram dust -> asthma symptomKuehr J, et al. JACI. 1994; 94: 44. Platts-Mills TE. JACI. 1992; 89: 1046.Exposure to Group I antigen > 10 microgram/gram dust in the 1st yr of life -> risk of asthma development at 11 yrs of ageSporik R, et al. NEJM. 1990; 323: 502.

  • (Cockroach) 3 allergenCockroach allergens allergens Cockroach allergen levels > 2 unit/gm dust -> sensitization threshold specific IgE cockroachEggleston PA, et al. JACI. 1998; 102:563.

  • (Cockroach) Cockroach allergen levels: 0.05 2 unit/gm -> risk for asthma 8.3 CR allergen levels > 2 unit/gm -> risk for asthma 35.9 Litonjua AA, et al. JACI. 2001; 107: 41.Patients who were allergic to CR -> risk for airway hyper-responsiveness 4 timesTepas EC, et al. Chest. 2006; 129: 1500.CR allergen level > 8 unit/gm -> asthma hospitalization 3 Rosenstreich DL, et al. NEJM. 1997;336:1356.

  • (Cockroach) 20-48% of Homes without visible CR still contain detectable CR allergen in dust samples Matsui EC, et al. JACI.2003; 112(1):87.CR allergen level > 8 unit/gm -> morbidity threshold CR allergen particles > 10 < 30 Study in asthmatic children showed bedding encasing, vacuuming and air cleaner (with HEPA filter); and / or cockroach controls by specialist -> asthma symptoms, absent school day, unscheduled doctor visitMorgan WJ, et al. NEJM. 2004;351:1068.

  • Cat and dog

  • Cat, dog allergens 2-15 Cat major allergens: Fel d 1 Dog major allergens: Can f 1 Mouse allergens 2-20 Mouse major allergen: Mus m 1 mouse Allergens 2-3 ..Cat allergen in the bed -> risk for cat sensitization at age 2 yr Chen CM, et al. JACI.2007;119:1148.

  • Sensitization level of cat allergen is 1 microgram/gmSensitization level of dog allergen is 2 microgram/gmAlmqvist C. Clin Rev Allergy Immunol.2005;28:25.Cat sensitization -> risk factor for asthma development 3.5 times, AR development 5.4 times Schafer T, et al. Allergy.2007;62:1282.Fel d 1 > 8 g/gm, Can f 1 > 10 g/gm -> threshold level for risk of asthma developmentIngram JM, et al. JACI.1995; 96: 449.

  • Cigarette smoking (passive or active)Deleterious effects in asthmatic patients: risk of hospitalization, poor asthma control, rate of decline of lung function risk of lung cancer risk of COPD risk of cardiovascular diseases the effectiveness of inhaled and oral steroidExposure in pregnancy: risk of asthma and lower respiratory infection in childrenGINA 2014

  • Common Air PollutantsCaused by the burning of solid fuel, inefficient stoves: - Particulate matter (PM) - Ozone (O3) - nitrogen dioxide (NO2) - sulfur dioxide (SO2)Others: CO, CO2, aldehydes, benzene, polyaromatic c. Affect lungs: inflammation, ciliary clearance, impaired immune response (Bruce, Perez-Padilla, and Albalak 2000)

  • : Particulate matter (PM)PM2.5 : particles < 2.5 m - originates primarily from combustion sourcesPM10: particle size 2.5-10 m - primarily produced by mechanical processes such as construction activities, road dust re-suspension and windPM2.5: 10 g/m3 annual area or 25 g/m3 24-hr meanPM10: 20 g/m3 annual area or 50 g/m3 24-hr meanWHO Air Quality Guideline

  • Ozone (O3)Formed in the atmosphere photochemical reactions in the presence of sunlight and precursor pollutants, such as the oxides of nitrogen (NO) and volatile organic compounds (VOC) lung function, airway inflammation respiratory morbidity in childrenO3 : 100 g/m3 8-hour meanWHO Air Quality Guideline

  • Nitrogen dioxide (NO2)A marker for the combustion-related pollutantsMost atmospheric NO2 is emitted as NO, which is rapidly oxidized by ozone to NO2 ->

  • Nitrogen dioxide (NO2)Bronchitis symptoms in asthmatic children lung function growth in children

    WHO Air Quality Guideline NO2: 40 g/m3 annual mean 200 g/m3 1-hour mean

  • Sulfur dioxide (SO2) SO2 SO2 WHO Air Quality Guideline SO2: 40 g/m3 annual mean or 200 g/m3 1-hour mean

  • Carbon monoxide (CO) hemoglobin RBC 200-250 0.1 ppm 0.5 5 ppm CO -> -> CO 9 ppm ( 2538) Indoor air quality ..

  • Carbon dioxide (CO2)Source: human breathing, 340 ppm 1000 ppm CO2 1000 ppmIndoor air quality ..

  • Volatile Organic Compounds (VOCs) (VOC) - Benzene- Methylene Chloride- Toluene- Styrene- Tetrachloroethylene Center of Excellence for Indoor Air Quality and Energy Management (IAQE):

  • Benzene -> Center of Excellence for Indoor Air Quality and Energy Management (IAQE):

  • Methylene Chloride Center of Excellence for Indoor Air Quality and Energy Management (IAQE):

  • Toluene Center of Excellence for Indoor Air Quality and Energy Management (IAQE):

  • Styrene Center of Excellence for Indoor Air Quality and Energy Management (IAQE):

  • Tetrachloroethylene

    Center of Excellence for Indoor Air Quality and Energy Management (IAQE):

  • Formaldehyde ( medium density fiber board)

  • Formaldehyde > 0.1 ppm nasal sinus cancer, nasopharyngeal cancer, brain cancer

  • Asbestos asbestos -> : ( O2), lung cancer, (mesothelioma)

  • Radon (): -> -> -> lung cancer 2 US EPA: < 148 Bq/m3 (2161 ) 9-1307 Bq/m3 ( 2543)

  • Particulate MatterStudy of homes in developing countries: - Conc. of PM10 averaged over 24-hr periods : 300- 3000 g/m3 - During cooking, PM10 in the kitchen and near the fire: up to 30,000 g/m3Saksena, Thompson, Smith 2004 - In Kenyan Masai homes: a 24-hr average of CO was 50 ppm Bruce and others 2002

  • - () 30 2520- . .. 2541+ .. 2549- 33 (..2535) ... 2522 2

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  • Allergen Avoidance& Allergen Elimination

  • House dust mite controls Strength of recommendationCover mattress and pillows with impermeable covers+++Wash bedding in hot water weekly +++Vacuum carpets frequently ++Remove stuffed animals from bed ++Remove wall to wall carpeting ++Remove upholstered furniture and curtains ++Dehumidify +Apply acaricides 0Sharma HP, et al. Pediatr Clin N Am. 2007; 54:103.

  • Cockroach Controls Strength of recommendationExterminate with gel or bait traps+++(professionally, if possible)Appropriately store and discard food+++Clean thoroughly ++Repair cracks and holes in structure +Sharma HP, et al. Pediatr Clin N Am. 2007; 54:103.

  • Cat and dog Controls Strength of recommendationDo not bring pet into home or find +++a new home for existing petClean home thoroughly after pet removal +++Remove carpets and upholstery after ++pet removalInstall allergen-proof mattress and pillow encasing ++Restrict pet from bedroom 0Use HEPA air filter in bedroom 0Sharma HP, et al. Pediatr Clin N Am. 2007; 54: 103.

  • Interventions for Reducing exposure to indoor air pollutionSource of pollution:- Improved cooking device: improved stove with flue- Alternative fuel-cooker combinations: kerosene, electricity, solar cooker, liquid petroleum gas - Reduced need for the fire: solar water heatingLiving environment- Improved ventilation- Kitchen design and placement of the stoveUser behaviors: avoiding the smoke

  • Center of Excellence for Indoor Air Quality and Energy Management (IAQE):

  • Center of Excellence for Indoor Air Quality and Energy Management (IAQE):



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