A.S.L.
& Associates over the past 32
years has developed extensive experience and resources for the
purpose of assessing the potential impacts of air pollution on
the environment. Corporate clients include major industrial,
environmental, and governmental groups. The Company's President
and Founder, Dr. Allen S. Lefohn, has focused the Corporation on those environmental
issues that directly link pollutant exposure with both human
health and vegetation effects.
A.S.L. & Associates is unique
in its approach toward developing solutions to complex
issues. The company teams with leading scientists from around
the world to focus on complex scientific issues. Statistical
biological results and air quality characterization analyses
are easily presented in GIS, as well as other creative visual
summaries. Because our research is cutting edge, more than 90%
of our results are published in major peer-reviewed scientific
journals. At times, A.S.L. & Associates is asked to prepare
materials that are presented to those responsible for the air
pollution standard-setting process.
A.S.L. & Associates is unique
in its approach to performing its research. Besides receiving
research funding from its clients, A.S.L. & Associates funds
its own research. A.S.L. & Associates believes that in economic
upswings as well as economic downswings, it is important to continue
to develop the research results that provide important inputs
into learning more about the relationship between air pollution
exposure and (1) human health and (2) vegetation effects. For
the purpose of informing the general public, researchers, and
policymakers, research results are placed on A.S.L. & Associates'
web site (asl-associates.com). The web site is visited by thousands from
around the world each month. Some of the most popular pages visited
on the web site are those associated with (1) maps summarizing
violation areas for criteria air pollutants, (2) natural background
of surface ozone, (3) the biological importance of the higher
hourly average air pollution concentrations more than the mid-
and lower-level values, (4) our exposure- and dose-response research
on vegetation and human health, (5) the "piston effect"
and how it affects the reduction of hourly average surface ozone
concentrations as air pollutant emissions are reduced, (6) our
global sulfur emissions database from 1850-1990, (7) spatial
interpolation of surface ozone (i.e., kriging), (8) concerns
about assumptions associated with epidemiological modeling, (9)
our peer-review publications list, and (10) our Albert Einstein
quotations with references. Below is a summary graph of visits
to the A.S.L. & Associates' web site for a recent period.
The Company's President and Founder,
Dr. Allen S. Lefohn,
and his research associates have established an outstanding reputation
for providing research and analyses in several major areas. Some
of these research areas are
Standard-Setting
Evaluations
- The evaluation
of the limitations associated with exposure models that relate
to risk assessment methodologies.
- The evaluation of the
strengths and weaknesses associated with epidemiological methodology and the standard-setting process.
- The evaluation of PM2.5
and ozone data for assessing one of the key assumptions in epidemiological
assessments that spatial variability does not exist.
- The evaluation and assessment of ambient air quality standards
and critical levels/loads.
- The evaluation and assessment of using the W126 cumulative ozone exposure index
as a secondary standard to protect vegetation.
- Developing rollback models
for assessing alternative risk scenarios for federal government
air pollution rulemaking processes.
- Developing the scientific
rationale for explaining the "piston" effect, which affects our ability
to attain surface ozone standards.
- The identification of
areas in the United States that violate
Federal ozone, PM-2.5, and other criteria pollutant standards.
- Characterizing policy-relevant and natural background ozone levels and their relationship
to the standard-setting process.
- Evaluating the occurrences
of elevated short-term
5-minute SO2 average
concentrations in the U.S.
- The evaluation
of mathematical models that relate short-term 5-minute SO2 concentrations
with hourly average concentrations.
Human
Health Effects
Vegetation
Effects
- The development of vegetation
and human health exposure-response
relationships.
- Explore the efficacy of
various defense mechanisms for helping to define "effective"
dose.
- The development of a bridge that allow for the use of exposure-response and dose-response
data for predicting vegetation effects.
- Explore the efficacy of
applying the U.S. 8-hour ozone standard to protect forests and
agricultural crops.
- Identify "areas of concern" for areas that may be impacted
by ozone exposures for forests in North Carolina, Tennessee,
and South Carolina.
- Summarize ozone exposures that may have an effect on vegetation
grown in the Southern Appalachian region of the United States.
- Summarize the state-of-knowledge
for the U.S. EPA of the status of the use of relevant exposure indices for predicting ozone effects on vegetation (Chapter
9 of the EPA's 2006 Ozone Criteria Document).
- Develop exposure-response relationships for tree seedlings using data from
five intensive Southern Commercial Forest Research Cooperatives.
- The design
of vegetation air pollution exposure studies that mimic ambient
conditions.
- Application of geographic information system (GIS) approaches that integrate vegetation
effects with exposure information.
Air Quality
Characterizations
- Determine ozone trends analyses on anthropogenically influenced monitoring
sites in the United States and on worldwide background ozone
"signature" monitoring sites.
- The application of mathematical interpolation techniques (e.g., kriging) to predict ozone
exposures across the United States.
- The identification of
clean sites in the
United States and
other parts in the world that can serve as indicators of natural
background for surface ozone and other pollutants.
- The identification of
clean sites in the United States that can serve as indicators
of natural background for particulate matter.
- Summarize the state-of-science
for the National Acid Precipitation Assessment Program (NAPAP)
for the air quality characterization of agricultural and forested
areas for vegetation effects purposes.
- Summarize the state-of-knowledge
for the U.S. EPA of the air quality characterization of ozone
for urban and rural areas for health and vegetation effects purposes
(Chapter 4 of the 1996 Ozone Criteria Document and Chapter 3
of the 2006 Ozone Criteria Document).
- The development of scientifically
defensible approaches to predict ozone levels as a function of
emission reductions (i.e., rollback methods).
- The characterization of
air pollution co-occurrences under ambient conditions for designing
human health and vegetation exposure experiments.
- Defining air quality characterization in biologically meaningful terms.
- Develop a global sulfur emissions inventory for purposes of the development of
global climate models.
Some of the published research results
can be reviewed at our publications web page. We welcome your suggestions on future
environmental research efforts as well as your participation
in our efforts. For further information, please contact us at
