What is the bucket?
The community based "bucket" air sampling system was developed in
California in 1994, when local residents living near oil refineries
and chemical plants decided to do something to put an end
to the pollution in their neighbourhood. These residents sought
expert assistance to develop a system of independent monitoring
of air pollution. Together they designed simple air monitoring
device, called a "bucket" to take grab air samples.
Subsequently, a US NGO, Communities for a Better Environment
(CBE) organized a regional effort to provide "buckets"
to five industrial communities in the San Francisco Bay area.
The CBE also convinced the U.S. EPA to verify and endorse the "bucket".
The EPA provided $90,000 to test the scientific credibility
of the 'bucket", the outcome of which was approval from
the EPA of the scientific reliability of the "bucket"
technology and methodology of collecting air samples.
In 2000, groundWork, with the assistance of CBE and another US based
NGO, SAEPEJ (the South African Exchange Programme for Environmental
Justice) introduced the "bucket' to communities in SA.
Community workshops were held in South Durban, Port Elizabeth,
Cape Town and Sasolburg, and air samples were taken.In 2002
groundWork is seeking to develop community air monitoring
systems, using the "bucket", in heavily polluted
neighbourhoods in SA and Southern Africa.
How does the "bucket" work?
The "bucket" is quite literally a nappy bucket which
has been adapted to take air samples. Inside the sealed bucket
is a tedlar sampling bag. The air is sucked out of the bucket
using a handheld pump, creating a vacuum inside the bucket.
Then a valve attached to the teflon bag is opened, and air
is sucked into the bag to fill the vacuum in the bucket. Once
the bag is filled with air it is removed from the bucket and
sent to a laboratory for testing.
What pollutants do the buckets test for?
The "buckets" can be used to test for just about
every gas in the air (ambient air). This includes organic
and inorganic gases and sulphur compounds. The bucket cannot
be used to test for particulate matter, including heavy metals,
nor or toxins that normally attach themselves to particles,
eg dioxins.
What are the results of "bucket" samples in SA?
Bucket samples have been taken in South Durban (on the fenceline
of the Engen refinery), in Cape Town (on the fenceline of
the Caltex refinery) and in Sasolburg (several samples taken
around Sasolburg). A variety of chemicals were found in the
samples. Below are some of the most important findings.
Benzene
Levels of benzene in the Sasolburg and Durban sample were
recorded at 29 parts per billion (ppb). This is the highest
benzene concentration ever detected in a bucket air sample
around a petroleum refinery. This was eight times higher than
the USA ambient air standard according to Dr Wilma Subra,
technical analyst for the samples taken in South Africa.
Benzene is a known human carcinogen. Long-term exposure to
benzene in the air can cause leukaemia and anaemia. Breathing
benzene can cause drowsiness, dizziness, and unconsciousness.
It can also cause excessive bleeding and can affect the immune
system.
Toluene
High levels of toluene were found in all three samples with
ranges from 24 ppb to 10 ppb. These levels were four times
higher those normally found during upset conditions around
petroleum refineries in the USA.
Toluene affects the brain. Repeated exposure to high levels
can cause permanent brain and speech damage, vision and hearing
problems, loss of muscle control, and poor balance. It can
also cause memory loss, decreased mental ability and kidney
failure. Chronic inhalation exposure can cause unconsciousness,
and even death.
Over 30 other toxic chemicals with found in the various samples
undertaken. Many of the levels of these chemicals were found
at levels higher than acceptable background levels in the
USA. In the Caltex sample the fuel additive MTBE was found.
This chemical has come under serious scrutiny in the USA and
has been the issue of various litigation battles and congress
hearings to date. Caltex denied that they use MTBE.
What is most alarming is the accumulative impact these chemicals
would have on people who have been constantly faced with this
cocktail of pollutants for several decades.
Other information sources:
Communities for a Better Environment: www.igc.org/cbesf/
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