Built Environment and Health PDF

Built Environment and Health Prof Samuel Yu, DEnv, CIH Health Safety and Environment Office Division of Environment and Sustainability Hong Kong University of Science & Technology Buildings  Shelter us from natural elements  Protect us from harms  Provide more amenable environment, including...

Built Environment and Health Prof Samuel Yu, DEnv, CIH Health Safety and Environment Office Division of Environment and Sustainability Hong Kong University of Science & Technology Buildings  Shelter us from natural elements  Protect us from harms  Provide more amenable environment, including light, sound and privacy  Allow environmental controls  Technology brings sophisticated control, but not without a price  The most impactful man-made environment Health Considerations  Environmental health  Built environment and health  Occupational health  Residential health PRS Q1, Q2 Indoor Air Quality  The IAQ Problem  The HK IAQ Certification Scheme  IAQ Parameters—Sources and Effects  IAQ Management at HKUST The IAQ Problem Source: DreamWorks The Croods  Indoor air pollutant may be 2-5 times, up to >100 times, of outdoor levels  People in industrialized nations spend 70-90% of their time indoors (infants, elderly, chronic patients even higher)  Locations involving prolonged exposure: home, school, workplace  In last several decades exposure to indoor air pollutants has increased Problem Getting Worse...  More tightly sealed buildings  Reduce ventilation to save energy  Environmental tobacco smoke  Increased use of synthetic materials inside buildings  Increased use of personal care products, pesticides, other household chemicals  Indoor fuel burning  Outdoor air pollution Undesirable Effects of Poor IAQ  Two levels of physical impact to humans Nuisance and discomfort Ill health, could even be fatal  In the workplace, increase in absenteeism and lower productivity PRS Q3-Q5 HK IAQ Certification Scheme Guidance Notes  Guidance Notes for the Management of Indoor Air Quality in Offices and Public Places (Sept 2003)  Excluded industrial, medical and domestic buildings  Comprehensive background information and practical guidelines to prevent and/or remediate IAQ problems Certification Scheme  Voluntary scheme for offices and public places served by MVAC (central AC, not window-mounted)  2 tiers of certification by competent persons, from Feb 08, by IAQ Certificate Issuing Body (CIB)  Initial and every 5 year assess all 12 parameters, 4 yearly re-certification in between only measure CO2, RSP & mould  Building manager to ensure maintenance of IAQ at certified level IAQ Parameters--Physical  Air Temperature  Relative Humidity  Air Movement  Dropped in 2019 Guide IAQ Parameters--Chemical  Carbon dioxide  Carbon monoxide  Ozone  Nitrogen dioxide  Total volatile organic compounds  Formaldehyde  Respirable Suspended Particulates  Radon Carbon Dioxide  Ultimate oxidation product of carbonaceous compounds  Indoor sources: human and other organisms  NOT a common outdoor air pollutant  Widely use as indicator of IAQ  Not toxic CO2 as an IAQ Indicator Carbon Monoxide  Product of incomplete combustion of carbonaceous materials  Exhaust component of most combustion sources, e.g. automobile, diesel engine  Common outdoor air pollutant  Indoor sources: combustion process  Highly toxic at high concentration  Chronic exposure may affect nervous and cardiovascular systems Ozone  Byproduct of high energy processes, e.g. electric arc, UV irradiation  Natural and man-made sources  Common outdoor pollutants  Products of photochemical reactions  Indoor sources: office equipment  Cause sore throat, headache, cough  Chronic exposure can damage lung functions Nitrogen Dioxide  Combustion byproduct  Natural and man-made sources  Common outdoor air pollutant  Indoor sources: combustion process  Cause burning sensation, sore throat, cough  Chronic exposure cause emphysema, may have effects on immune system decreasing resistance to infection Total Volatile Organic Compounds  Mostly petrochemical products including fuels, solvents  Natural and man-made sources  Common outdoor air pollutants  Indoor sources: cleaning products, cosmetics, office supplies, etc  Chronic exposure may affect nervous system, liver and kidney, some are carcinogens Formaldehyde  Common ingredient in industrial solvents and synthetic materials  NOT a common outdoor air pollutant  Indoor sources: carpet, synthetic fibers & boards, foams, printed materials  Severely irritating to eyes and respiratory tract  Confirmed human carcinogen (nasal, nasal pharyngeal, possibly leukemia) Respirable Suspended Particulate  Particulate Matters (10m) (PM10)  Can penetrate deep into human lung  Composition area & seasonal dependent  Common outdoor air pollutant  Sources: building materials, human, clothing, etc.  Cause respiratory irritation, asthma  Statistically linked to higher hospital admission rate, mortality rate Radon  Naturally occurring radioactive gas  Indoor sources: geologic materials rich in uranium, e.g. granite  Together with its decay products increase chance of lung cancer  Radon itself serves as a carrier, the decay products cause most of the damage IAQ Parameters--Biological  Airborne bacteria  Mould (assessment by checklist) added as a parameter in 2019 Guide Airborne Bacteria and Fungi  Natural sources: soil, water, vegetation  May multiply in suitable indoor locations, i.e. wet spots  Exist in bacterial cells, fungal hyphae, and spores  May also come from infected occupants Bacteria  Legionnaire’s Disease  Tuberculosis  Opportunistic pathogenic bacteria (e.g. Pseudomonas) Legionella pneumophila Mycobacterium tuberculosis Fungi  Stachybotrys chartarum  Aspergillus sp.  Penicillium sp.  Fungi are capable to cause Allergic Toxigenic Pathogenic Stachybotrys chartarum Aspergillus sp Penicillium sp. 12 IAQ Parameters—Old and New  Old (2003): 3 physical 8 chemical 1 biological  New (from 2019) 8 chemical + 2 existing parameters add short-term sampling 1 biological + 1 new parameter by checklist Sick Building Syndrome  Different temporary symptoms related to staying in a particular building  Sore/running eyes, blocked/running nose, sneezing, dry throat, lethargy, headache, asthma  Symptoms subside after leaving the building  Exact cause not defined Building Related Illness  Caused by particular microbe  Depends on Inhaled dose Individual susceptibility Virulence of agent  Symptoms persist after leaving the building IAQ Management at HKUST  Design  Maintenance  Assessment  Response  Remediation Design  IAQ was considered in original design of Academic Building Occupancy: 5-8 L/s/person Use: office 1-2 air change/hour, Laboratory 6-10 air change/hour  Comply in general with international standard: e.g. ASHRAE 62  Upgrade in progress according to revised ASHRAE standard 8 L/s/person Maintenance  Continuous monitoring thru computerized Building Management System  Regular preventive maintenance by FMO/BS  Cleaning of ventilation system Changing filters Cleaning air handling units, fan coil units Air duct inspection  Monitoring of general IAQ parameters: Temp, RH, CO2 Assessment  Achieved IAQ certification Good Class: Library, Lecture theatres, Conference Lodge common areas & restaurant, LG7 Canteen Excellent Class: CYT, GGT common areas, Indoor Sports Hall, LG5 Student Union office  Will maintain and pursue further certifications Response  Response to IAQ complaints  On site measurement by field instruments  Laboratory analysis  Remedial actions  Confirmation Remediation  Source Control  Ventilation  Air Treatment  Administrative Measures PRS Q6 Recapping  Built environment perhaps the most prolific and prominent man-made environment  Indoor air quality is one of the top environmental health concerns  Various health impacts can be caused by indoor air pollutants  Management through design, installation, and maintenance of ventilation system End of Part 1