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Short term exposures to fine particulates: What the
health data are telling us
Dave Brown, Environment and Human Health Inc,
Westport,
CT
Public Health Implications of Outdoor Wood Boiler
Exposure
Phil Johnson, The Heinz Endowments,
Pittsburgh, PA
Exposure Risk-Reduction Behavior- The New Canadian Air
Quality Health Index (AQHI)
Ken Maybee, Barbara Mackinnon, New
Brunswick Lung Association,
Fredericton,
NB,
Canada
Approaches to Assessing Health Care Costs Associated
with Air Pollution
Mary E. Davis, Tufts University,
Medford,
MA
Short Term Exposures to
Fine Particulates:
What the
Heath Data are Telling Us
David Robert Brown Sc.D.
Environment and Human Health. Inc., 65
Bulkley Avenue (North), Westport CT, Email:
npawlet@aol.com
Regulatory guidance for wood and other biofuels
emissions has been or is being developed by the
Department of Environmental Protection or State and
Local Government.
The guidance is predicated on an assumption that
the NAAQS 24 hour PM 2.5 is protective of respiratory
and cardiovascular inhalation hazard at local settings.
It is not.
Short term exposures occur. Human respiratory and
cardiovascular attacks from particulate matter and wood
smoke emissions are induced by fine particulate
exposures of two hours or less. Reliance on the NAAQS 24
hour PM 2.5 A 24 hour standard fails to capture the
hazard from the fumigation of local neighborhoods that
occurs on 25% of the days in the northeast.
Neither the NESCAUM report nor EPA modeling
considers hourly local fumigation exposures.
During periods of fumigation elevated stacks will
not protect the neighborhood. Very high levels of PM are
reached at nearby houses.
The heating systems in these houses draw the
fumes into the house creating a very high level of
particulate and wood smoke that persists for several
hours in the house.
Health standards need to consider the actual
physiological and dosing conditions within the
appropriate exposure time frame.
Examples from actual monitoring data: 1) Personal
monitor response to outdoor bus source in Fairfield
Connecticut 2) OWB exposures 3) Particulate responses to
local meteorological conditions in Connecticut 4)
Particulate concentrations inside a New Brunswick,
Canada School 5) Seasonal patterns of indoor aldehydes
and BTX in houses in Stowe, Vermont and 5) Indoor
effects from an outdoor wood boiler in Wisconsin were
analyzed for exposure implications. That analysis
showed: 1) Combustion in nearby buildings draw smoke
from the plume into the building due to oxygen demand
from their stoves and furnaces. 2) Buildings heated with
OWB do not draw in smoke because there is no combustion
inside of the building 3) The half time of removal of
smoke from contaminated houses is about 1 hr. At least 3
hrs are required to clear 90% of smoke from building. 4)
Stagnation of air flow in morning and evening inhibit
dilution of the cooled smoke plumes. 5) Plumes fail to
rise and frequently fall because the plume is not warmer
than the surrounding air.
The consolidated plumes travel long distances
(100s of yards).
Because
adverse mixing conditions occur at least 25% of
the days in New England
guidance or standards based on the
NAAQS 24 hour PM 2.5 is not protective of
respiratory and cardiovascular inhalation hazard.
The use of total inhaled dose is a more
appropriate way to evaluate the actual risks to
susceptible populations near sites burning wood and
other biofuels.
Public Health Implications of Outdoor Wood Boiler
Exposure
Philip R.S. Johnson, The Heinz
Endowments, 625 Liberty Avenue, 30th
Floor,
Pittsburgh, PA
15222-3115,
USA, Tel:
412-281-5777, Email: pjohnson@heinz.org
Outdoor wood boilers (OWB) are
residential hydronic heaters that have rapidly
proliferated in the U.S.
and
Canada
in recent years in parallel with the increased focus on
biomass combustion energy. OWBs may emit from upwards of
37,000 to 250,000 tons per year of fine particulate
matter (PM2.5) in the U.S., in addition to other criteria
and hazardous air pollutants. Many existing units have
no emissions controls, generate smoke plumes that can
fumigate micro-scale and area-scale settings, operate
year-round and can be used to burn non-ideal fuels. In
wood burning areas, receptor populations can experience
especially elevated transient and sustained exposures.
Peaking conditions can last from minutes to several
hours and then disappear, only to reemerge later in the
day, over the course of weeks and months.
Some local and state efforts to
regulate OWBs have relied on distance-predicated setback
requirements derived from models and the 24-hr average
PM National Ambient Air Quality Standard (NAAQS). For a
subset of the receptor population, there remains the
possibility of widespread vulnerability to airborne
exposure over variable spatial and temporal scales. This
raises the question as to whether the PM NAAQS and
current OWB regulations are sufficiently protective of
public health.
Regulations could conceive of OWBs
as unique airborne threats subjecting individual and
community-scale populations to a cumulative series of
episodic exposure events on a continual basis. Exposure
assessment and risk characterization should inform
regulatory response, with explicit consideration of
real-world OWB operating variables, terrain,
meteorology, demography, field monitoring and health
effects data.
Approaches to Assessing Health Care Costs Associated
with Air Pollution
Mary E Davis,
Tufts
University,
97 Talbot Ave,
Medford, MA,
02155,
USA;
Tel: 617-627-4719, Email: mary.davis@tufts.edu
Understanding the economic impact
of air pollution-related illnesses is important from a
public health perspective and is essential to the risk
assessment process.
In order to best evaluate the effectiveness of
emission restrictions or other limitations on air
pollution-generating activities, we must first identify
the magnitude of the negative impact on human health.
Although there is no clear cut economic
methodology for quantifying the health care costs
associated with air pollution, a number of techniques
have been developed that will be discussed in detail.
These include both ‘stated’ and ‘revealed’
preference methods, as well as a standard ‘cost of
illness’ approach.
The stated preference approach bases the health
impact on carefully worded survey responses to
‘willingness to pay’ questions, while revealed
preference methods identify the perceived health care
benefit/cost using statistical techniques and data on
actual consumer behavior.
The ‘cost of illness’ approach calculates the
cost of treating or living with the illness under the
assumption that society should be willing to pay at
least this amount to avoid it.
Finally, differences between quantifying costs
related to morbidity versus mortality will be examined,
and areas in need of further research will be
identified.
Examples will be drawn from health care costs of
respiratory illnesses related to air pollution exposure,
such as asthma and lung cancer.
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