State of California
AIR RESOURCES BOARD
515 South Olive
Los Angeles, CA
September 29, 1977
77-20-1 Report on Effects of Air Pollution on Children.
77-20-2 Public Hearing to Consider Amendments to Vehicle 1
Emission Regulations in Light of New Federal Waiver
77-20-3 Status Report Regarding Reconsideration of Sulfate 43
77-20-4 Other Business -
a. Research Proposals
b. Executive Session - Personnel & Litigation
ITEM NO.: 77-20-2
Public Hearing to consider Proposed Changes to Motor Vehicle
Emission Standards, Test Procedures, and Enforcement Programs.
Adopt Resolution 77-48.
The Clean Air Act amendments of 1977 were signed into law on
August 7, 1977. Several changes were made to the requirements
for a waiver of Federal preemption under Section 209(b) of the
Clean Air Act. In order to obtain a waiver under the amended
Clean Air Act, the staff has determined that the Board's
regulations must satisfy the following conditions:
1. There must be compelling and extraordinary conditions
in California which require the state standards and/or
2. California must find that its standards will be, in the
aggregate, at least as protective of public health and
welfare as applicable Federal standards. Such finding
cannot be arbitrary and capricious.
3. California's standards and test and enforcement
procedures must be technologically feasible within the
available lead time, giving consideration to the cost
These new conditions apply to several California Waiver requests
now pending before EPA. In order to comply with these new
conditions for a waiver, the staff is recommending that the Board
make several changes to its motor vehicle emission standards,
test procedures, and enforcement programs outlined in Resolution
77-48 and this staff report. These changes make certain
California standards somewhat more stringent in order to achieve
parity with new Federal standards recently mandated by Congress.
In addition, the staff is requesting that the Board make findings
to the effect that its motor vehicle standards, test procedures,
and enforcement programs which have EPA waivers pending are at
least as protective of public health and welfare as comparable
Federal standards, both individually and in the aggregate. These
actions should make ARB regulations more consistent with Federal
regulations and should facilitate the Administrator's decision to
grant California waivers of Section 209(a) of the Clean Air Act
for recent ARB regulations.
ITEM NO.: 77-20-3
Review of the Sulfate Ambient Air Quality Standard.
None. Informational report.
The staff has reviewed the most recent information pertaining to
ambient sulfate and its effects, much of it published within the
past five years. The staff concludes that:
1. The unique meteorological and topographical features, high
emission density and rapid conversion of SO2 to sulfate in
the SCAB have led to high concentrations of sulfates
exceeding the current 25 ug/m3 sulfate standard by a factor
of almost three in the Los Angeles and Bakersfield areas.
Research results show that the sulfate aerosol in the urban
areas of California consists of submicron particles which
are not only respirable but also scatter visible light and
thus degrade atmospheric visibility. The ACHEX study shows
that sulfates are 2 to 3 times more effective, on a weight
basis, than other aerosols in degrading visibility. Thus,
if sulfates were fully controlled, a 25 to 37% improvement
in visibility would result. Therefore, achievement of the
total suspended particulate and visibility standards will
require that ambient concentrations be reduced to at least
the level of the current standard.
2. Every effort should be made to limit the levels of
atmospheric sulfates before more serious harm to human
health occurs. Laboratory experiments have demonstrated
that sulfate aerosols are much more potent irritants than is
SO2. Recent toxicological studies suggest that sulfates may
be particularly effective in facilitating the release of
toxic histamine to sensitive lung tissue. These
investigations may not prove a cause-and-effect relationship
between ambient sulfates and adverse health effects but the
consistency of the results is such that one must conclude
that an association does exist.
3. Sulfate in the form of acid mist, acid precipitation and
suspended aerosols can adversely affect California's
sensitive ecosystems such as the agriculture, forest and
other ecosystems by direct contact with vegetation,
oligotrophic lakes and granitic based soils, or indirectly
by sulfate accumulation in vegetation. Furthermore,
California already has a pollution burden (e.g. nitrates)
that can contribute to acid mist and precipitation.
Therefore, the sulfate standard must be set to protect
sensitive ecosystems before irreversible damage occurs.
4. The current high-volume 24-hour sampling method for sulfate
and the current analytical methods can adequately identify
excesses to the 25 ug/m3 standard.
5. The established interim standard or significant harm
level of 25 ug/m3 suspended sulfate should still be
considered an initial step towards an ambient air
quality standard. The interim standard should be
reviewed annually, with particular emphasis on control
of aerosol in the respirable size range and on
standards based upon averaging periods that are most
closely associated with adverse human health responses.