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Pollution in Homes
Here are the most recent reports about cleaning products in the home
that every person who lives in a home should read. According to this
report, a majority of people are possibly suffering from a form of
chronic exposure syndrome, as in a chemical reaction and mutation.
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Research Summary: Pollution in Homes
14 February 2007 - abc7news.com
Feb. 14 - UC Berkeley study finds that indoor use of
many cleaners, air fresheners, may pose health risks. When used
indoors under certain conditions, many common household cleaners and
air fresheners emit toxic pollutants at levels that may lead to health
risks, according to a new study by researchers at the University of
California, Berkeley, and Lawrence Berkeley National
Laboratory. Exposure levels to some of the pollutants -- and to the
secondary pollutants formed when some of the products mix with ozone
-- may exceed regulatory guidelines when a large surface is cleaned in
a small room or when the products are used regularly, resulting in
chronic exposure, according to the study.
The study is the first to measure emissions and concentrations of
primary and secondary toxic compounds produced by these products under
typical indoor use conditions, and it examines the potential hazards
of small-scale yet widespread utilization of an array of products
designed for household use.
"We've focused a lot of effort in the last decades on controlling the
big sources of air pollution and on the chemicals in consumer products
that contribute to outdoor ozone formation. However, now we've learned
that we need to pay attention to other aspects of pollution sources
that are right under our nose," said William Nazaroff, a UC Berkeley
professor of environmental engineering and the study's lead author.
To comply with its mandate to protect public health and welfare, for
the past four decades the California Air Resources Board (ARB) has
been developing and implementing regulatory programs to reduce air
pollution in the state. These regulations also cover emissions of
volatile organic compounds from consumer products used in homes and
institutions.
Several years ago, when a handful of new studies raised the concern
that consumer products may be contributing to indoor pollution levels
in ways that were not fully understood, the ARB commissioned Nazaroff
and his team to study the problem.
Four years in the making, the team's 330-page study and report,
"Indoor Air
Chemistry: Cleaning Agents, Ozone and Toxic Air Contaminants," was
posted online by the ARB on Wednesday, May 10, at http://www.arb.ca.gov/research/apr/past/indoor.htm.
The ARB asked Nazaroff and his team to focus their work in two areas:
an investigation of toxic air contaminants in household cleaning
products and air fresheners, especially a class of chemicals known as
ethylene-based glycol ethers; and an examination of the chemistry that
occurs when such products are used indoors -- in particular, products
that contain a reactive group of chemicals called terpenes.
Ethylene-based glycol ethers are common, water-soluble solvents used
in a variety of cleaning agents, latex paints and other products. They
are classified as hazardous air pollutants under the U.S.
Environmental Protection Agency's 1990 Clean Air Act Amendments and as
toxic air contaminants by California's Air Resources Board. Their
toxicity varies with their chemical structure.
Terpenes are a class of chemicals found in pine, lemon and orange oils
that are used in many consumer products either as solvents or to
provide a distinctive scent. Although terpenes themselves are not
considered toxic, some recent studies have shown that they may react
with ozone to produce a number of toxic compounds. (The primary
constituent of smog, ozone enters the indoor environment from
infiltration of outdoor air, but is also produced indoors by some
office machines such as copiers or printers, and by some devices
marketed as "air purifiers" that purposely emit ozone into the indoor
environment.)
The research team's first task was to determine which household
products contain terpenes and glycol ethers, and in what quantities.
It compiled a list of the household cleaners and air fresheners
available at any of five chain retail outlets in Northern California,
then examined the labels and advertising claims (e.g. "pine-scented")
for these products and reviewed available product data sheets. Based
on this information, they selected the
21 products most likely to contain significant amounts of terpenes and
ethylene-based glycol ethers: four air fresheners and 17 cleaning
products, including at least one each of disinfectants,
general-purpose degreasers, general-purpose cleaners, wood cleaners,
furniture maintenance products, spot removers and multi-purpose
solvents.
A complete chemical analysis of these 21 products revealed that:
* Twelve contained terpenes and other ozone-reactive compounds at
levels ranging from 0.2 to 26 percent by mass.
* Six contained levels of ethylene-based glycol ethers of 0.8 to 9.6
percent by mass.
* Among the four air fresheners studied, three contained substantial
quantities of terpenes (9-14 percent by mass)
When the researchers tested the terpene-containing products in the
presence of ozone, they found that reactions produced very small
particles with properties like those found in smog and haze; other
oxidation products; and formaldehyde, a respiratory irritant that is
classified as a Group 1 carcinogen. (This designation by the
International Agency for Cancer Research is reserved for substances
for which there is sufficient evidence to conclude that they cause
cancer in humans.) The amounts of terpenes that were converted into
these pollutants was dependent on the amount of ozone present.
After completing their chemical analyses, the researchers ran a series
of 18 experiments to determine the levels of exposure people might be
subjected to when using the products in a confined space. The tests
were conducted in a 230-square-foot room with ventilation at an
ordinary level which provided approximately one air change every two
hours. In some tests of terpene-containing products, ozone was
introduced into the room at levels mimicking those that could occur in
households or offices.
The products were used in various ways according to package
directions: some at full-strength and others at various dilutions as
recommended on their labels. In some tests, used cleaning supplies
such as paper towels and sponges were left in the room. In others,
supplies were promptly removed.
The tests produced various results -- some reassuring, and some
raising concerns.
The good news, the researchers reported, is that when people use the
products under ordinary circumstances, their exposure to
ethylene-based glycol ethers, formaldehyde and fine particles will
normally not reach guideline values: that is, levels set by regulatory
agencies as the maximum exposure levels believed to be safe. However,
the authors pointed out, because formaldehyde is also released from
other sources such as plywood and pressed wood products that are found
in most buildings, any increase in formaldehyde emissions is
undesirable. In several realistic use scenarios, the tests showed that
people could be exposed to potentially dangerous levels of toxic
pollutants. The scenarios included:
* Cleaning in a small, moderately ventilated bathroom. In calculations
based on emissions from one of the glycol-ether containing products,
the team found that a person who spends 15 minutes cleaning scale off
of a shower stall could inhale three times the "acute one-hour
exposure limit" for this compound set by the California Office of
Environmental Health Hazard Assessment.
* Air freshener and ozone in a child's bedroom. This scenario could
occur when people use both air fresheners and ozone-generating devices
simultaneously in a room. This could lead to exposures to formaldehyde
that are 25 percent higher than California's guideline value. Because
other sources of formaldehyde could also be present in the room,
exposure to formaldehyde would probably be even higher, the report
states.
* Cleaning when outdoor ozone levels are high. This scenario simulates
an apartment in Southern California on a day when the mid-afternoon
outdoor ozone concentration is high. A person who stays in the kitchen
for two hours after using a moderate amount of one of the terpene-containing
products would breathe in about one quarter of the total daily
guideline value for particulate matter.
* Multi-house cleaning by a professional home cleaner. Under this
scenario, a person who cleans four houses a day, five days per week,
50 weeks per year, would take in about 80 micrograms per day of
formaldehyde, double the guideline value set by California's
Proposition 65. In addition, the person's intake of fine particulate
matter during the hours spent cleaning would exceed the average
federal guideline level for an entire year. These quantities are in
addition to the formaldehyde and particulate matter that the person
would be exposed to from all other sources and activities during the
year.
The take-home message from these studies, according to Nazaroff, is
that everyone -- but especially cleaning professionals -- should be
cautious about overuse of products with high levels of ethylene-based
glycol ethers and terpenes. Rooms should be ventilated during and
after cleaning, some products should be used in diluted solutions as
opposed to full-strength, and cleaning supplies should be promptly
removed from occupied spaces once cleaning is done. Also, people
should avoid the use of ozone generators or ionizing air cleaners,
especially in the same space where terpene-containing cleaning
products or air fresheners are being used.
The report is an important milestone that highlights the need to
investigate potential health effects of ultrafine particles produced
in such reactions, said Bart Croes, chief of the ARB's Research
Division. "Dr. Nazaroff and his team have done a very thorough
scientific assessment of the emissions from cleaning products and how
they contribute to exposures of the users," Croes said. "Their results
indicate that we need to look beyond the directly emitted compounds."
The study cost $446,865, an amount wholly funded by the ARB.
The report's other authors are Beverly K. Coleman, a UC Berkeley Ph.D.
student with Nazaroff; Hugo Destaillats, Alfred T. Hodgson, Melissa M.
Lunden and Brett C. Singer, all at Lawrence Berkeley National
Laboratory; DeLing Liu, who was at UC Berkeley when she conducted the
work but is now with the Jet Propulsion Laboratory in Pasadena,
Calif.; and Charles J. Weschler, at the University of Medicine and
Dentistry of New Jersey and the Technical University of Denmark.
Copyright 2007, ABC7/KGO-TV/DT. For More Information:
William Nazaroff
Professor of Environmental Engineering
UC Berkeley
Brett Singer, Ph.D.
Environmental Scientist
Lawrence Berkeley Laboratory
Berkeley, California 94920
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