Civil Engineering Reference
In-Depth Information
Fig. 13.6
Comparison of PM10, PM2.5, and ultrafine PM.
Source
Reference [
33
], Slide 2
Fine Particles (PM2.5)
Fine Particles (
PM2.5
) are small, airborne particles with a diameter of 2.5
micrometers or less. PM2.5 that can penetrate deep into the lungs, causing
in
ammation of the airways, exacerbating lung and heart disease, increasing
hospital admissions and contributing to premature mortality. Sources of PM2.5
include all types of combustion sources; the elemental composition of PM2.5
can vary by source and determine PM2.5 health effects. Studies [
34
fl
36
] found
that motor vehicles contribute up to one-third of ambient PM2.5 in urban areas
in the US [
30
].
-
Ultra
ne Particulate Matters
ne particles (
UFP
or
Ultra
ne PM,
with diameter <0.1
µ
Ultra
m) are another
component of motor vehicle emissions, produced by gasoline and diesel
engines.
5.
Lead
Element that exists in fuels and absorption of it by human body leads to higher
Blood Lead that brings multiple adverse health results.
However, transportation
no longer accounts for a large share of pollution from lead
. Highway vehicles
currently account for less than 1 % of total lead emissions, primarily because of the
use of unleaded gasoline.
6.
Sulfur Dioxide
SO
2
is a gaseous pollutant formed by the combustion of fuels containing sulfur
(e.g., coal, oil). It is usually measured in winter, since the residual heating oil
contributes most of it to the city
'
s concurrent air pollution.
