Presentation on theme: "AIR POLLUTION AND HEALTH EFFECTS (II). PARTICULATE MATTER l Since the CAA(1956) a kind of complacency set in because smoke and SO 2 were very much reduced."— Presentation transcript:
AIR POLLUTION AND HEALTH EFFECTS (II)
PARTICULATE MATTER l Since the CAA(1956) a kind of complacency set in because smoke and SO 2 were very much reduced. l Some did notice an increase in fine particles Diesel Summer haze – secondary particles l Monitoring for PM 10 rather than TSP
QUARG INITIALLY POSITIVE ABOUT FUTURE l Emissions of pollutants from vehicles looked set to decrease… l Dockery et al (1993) six cities study An association between air pollution and mortality in six U.S. cities New England Journal of Medicine 329,
SIX CITY STUDY l A long term analysis of data on air pollution and mortality undertaken by Harvard School of Public Health MORTALITY FACTOR
NORTH-SOUTH DIVIDE Annual mean concentrations decrease northwards Sahelian dust Photochemistry Emissions Lack of resource and expertise in south created concern in EC <<
COMPOSITION OF DUSTS l Sardinia more than 80% of the Fe and Al come from the Sahara. Guerzoni, S et al Chemosphere (1999) l Declining emissions of fly ash from industrial plant may lower Ca and offset gains from reduced acidic emissions. Lee and Pacyna Atmos. Env. (1999)
RESPIRATORY SYSTEM Modern concerns relate more to the lung than the respiratory tract
l Size matters – particles need to be <3 μm to get deep in lung currents/vol2issue4/1lungimagingfi g1.html orama/Biology/Physiology/Physiolo gy.html /popups/alveoli_bh.htm tospanel/appendix_e.html PARTICULATE MATTER
l Size matters – particles need to be <3 μm to get deep in lung nel/appendix_e.html MSU College of Human Medicine John Hopkins School of Medicine PARTICULATE MATTER A= Alveolar TB = Tracheobronchial NPL = Nasal, Pharyngeal, Laryngeal Alveoli
SHORT TERM EXPOSURE RESPONSE TO PM 10
MONTHS LOSS OF LIFE
PARTICLES l PM10 - health effects complex... l Organics and metals l Compositional complexity and nanoscale heterogeneity [ Buseck et al, Atmospheric Geochemistry No ] Buseck et al
Mechanisms for removal involve macrophages ALVEOLAR MACROPHAGES MACROPHAGES MSU College of Human Medicine John Hopkins School of Medicine ALVEOLI PARTICULATE MATTER IN ALVOLI
INJURY FROM FINE PARTICLES
ALVEOLI KEY FACTORS IN EFFECTS OF PARTICULATE MATTER l Area/number l Oxidative stress l Hydroxyl radical activity – l Transition metals – Fe, V
OXIDATIVE STRESS l Transition metals and organics on the surface of the carbon core affect the antioxidant defences within the lung lining fluid. l Consumes the protective antioxidant l Macrophages overwhelmed and more (less active particles?) can reach the surface of the lung.
OXIDATIVE STRESS l Ascorbate and glutathione depletion as indicators of oxidative activity. l Measured in London HIGH TRAFFIC
PARTICLE TYPE Laden et al Association of fine particulate matter from different sources with daily mortality in six U.S. cities Environmental Health Perspectives 108, ( 2000) Impact of 10 μg/m 3 increase in PM2.5 from various sources
NON CLASSICAL IMPACTS LONG TERM (20a) PM EXPOSURE AND COGNITIVE FUNCTION IN THE ELDERLY Ranft et al Environmental Research (2009) l PM translocates to the brain which causes inflammation. l Brain inflammation is promotes neurodegenerative diseases (e.g. Alzheimer's). CERAD neuropsychological test battery (Consortium to Establish a Registry for Alzheimers Disease)
FOREST SMOKE IN CITIES l Health effects of particles problem of size problem of toxicity l Canadian fires affect US pollutant concentrations [ Wotawa and Trainer Science 288: (5464) ]
Photographs C.J. Park YELLOW DUST l Enormous worry in Asia about dust from the Loess plateau and its potential health effects. l May incorporate organic materials and also be carcinogenic.
DUST CHEMISTRY ORGANICS OZONE INTERACTIONS ORGANIC ACIDS SOLUBILZATION NEUTRALIZATION HNO 3 H 2 SO 4 DUST EMISSION HULIS SURFACTANTS More dust perhaps with agriculatural and climate change… but pollutants in cities coat on the dust.
MOONDUST l NASA wories about particles less than 3 m
LONG AND SHORT TERM EFFECTS Need to distinguish between the effects of fine particles and oxidative stress and long term effects of carcinogenesis
URBAN NANOPARTICLES <1 m l Traffic l Industry l Secondary production l … but also rapid nucleation Health concerns over smaller and smaller particles has driven the study of nanoparticles...
Los Angeles ULTRAFINES (50-100nm) Most abundant catalytic metals: Fe, Ti, Cr, Zn, Ce Cass et al Phil. Trans Some 10% of primary organic particles seem to be from cars...
l Surfactants in alveoli aid gas exchange, but also lung defence. l Would aerosol surfactants alter these functions? PULMONARY SURFACTANTS ALVEOLI
REGULATION OF PM l Confusion over mechanisms and measurement l Regulatory problems: uncertainty no-thresholds l Constitutional dilemmas TSP PM-10 PM-2.5
PROBLEMS WITH STANDARDS l Meeting limit values may not always reduce exposure most effectively CONCENTRATION LIMITVALUE Fails to meet limit value, but much reduced cumulative does CURRENT Meets limit value