Environmental Data Analysis BC ENV 3017

Atmospheric Particulates

Introduction:

particulates were first recognized as a problem in 1952 in London during a bad fog (fig)

Shortly there after British Parliament enacted clear air act that forbad the burning of soft coal in the center of London

Particulate matter in urban centers

aerosol = a colloid in which small solid or liquid particles are suspended in a gas
colloid = a mixture in which one substance is divided into minute particles (called colloidal particles) and dispersed throughout a second substance
Total Suspended Particulates (TSP), particle size 0.01 - 100µm
PM₁₀ = mass of particulate matter <= 10µm in diameter;

these particles enter lungs
in NYC data indicate that PM10 = 0.5 * TSP

PM_2.5 = mass of particulate matter <= 2.5µm in diameter

these particles enter the smallest spaces in the lungs

Particle sizes and composition

typical spectrum of particles (Fig)

ultrafine (0.01 - 0.1µm) = nucleation of saturated vapors (SO₂, NH₃, NO_x)

are affected by coagulation (gather together) and condensation

fine (0.1 - 2.5µm) = condensation of gases onto pre-existing particles

major constituents are SO₂, NH₃, NO_x, IC, OC and many trace metals
Too small to settle out and too large to coagulate into larger particles so have a long residence time (days) and travel great distances

coarse (2.5 - 100µm) = particles containing sea and soil (natural)

major constituents are Si, Al, Ca, Fe, Mn, Sr, Na, and K
particles >= 10µm settle from the atmosphere by sedimentation

composition of particles reflect their source; i.e. crustal material (dust from rocks) vs. acid aerosols and metals from energy use
anthropogenic sources vary but are usually dominated by fossil fuels (Fig)

burning fossil fuel is the source of most of the organics, most of the sulfate (SO₄) via SO₂ oxidation, most of NO_x , certain metals

there are also natural sources of sulfate, such as volcanoes, DMS (dimethyl sulfide) from oceans and estuaries
sulfates contribute to the formations of strong acids

amount of PM produced decreases from coal/diesel to gasoline to natural gas

old incinerators were also a major source

worst offenders are the small inefficient apartment building incinerators => black cloud of smoke
modern high tech incinerators can be built with very low particulate outputs

Trends

Emissions of PM10 until 2001
Trend of PM10 concentrations until 2001
Emissions of PM2.5 until 2001
PM2.5 concentrations, U.S.
Non attainment designation for PM-10 (Fig)

Health effects

how much air do you breathe per day?
intake of particles by average person.
healtheffects of PM include:

premature death;
respiratory related hospital admissions and emergency room visits;
aggravated asthma;
acute respiratory symptoms, including aggravated coughing and difficult or painful breathing;
chronic bronchitis;
decreased lung function that can be experienced as shortness of breath; and
work and school absences.

Asthma & particulates

25% of children in Harlem have Asthma (national average 6%)

hypothesized causes

indoor air

increased tightness of modern buildings & windows
molds, dandruffs (cockroach, rat, pet, human), rat & mice feces, pet hair, pollen, smoking

outdoor air

increase in fine particulates (10mm vs 2.5mm)
fine particles go further into the lungs thus decreasing the effectiveness of the lung

the NRDC estimates that each year about 64,000 people die prematurely from cardiopulmonary causes linked to particulate air pollution
Premature mortality due to particulate Air pollution in New York: ca 4000 (Tab)
current EPA standards: (NAAQS)

PM2.5: annual mean concentrations < 15 µg/m³ , and 24-hour average concentrations < 65 µg/m³
PM10: annual mean concentrations < 50 µg/m³ , and 24-hour average concentrations < 150 µg/m³
these standards will not take immediate effect, there is an implementation timetable for these standards

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