|
Towards a lower
chemical load for Australia
by Herbert Beauchamp, Toxic Chemicals Committee
(TCC),
Total Environment Centre, Sydney
The price of living in a large city is a
significant chemical load associated with polluted air, water and food
which reduces the quality of life. Governments will only respond to
citizens' complaints when conditions become intolerable e.g. in
Australia in the 1-4 year age group there may be more than half a
million children who have elevated blood lead levels.
TCC here proposes a number of concrete steps which
can be taken by federal or state governments in 10 areas where better
control of lead is required.
Reducing lead in petrol
Except for people living close to smelters, or near
contaminated sites or those with occupational or hobby exposure, the
most important method of reducing lead is the rapid phase out of lead in
petrol. Australia has the second highest motor car ownership in the
world, the highest concentration of population in cities, and produces
the highest per capita lead load from petrol sources. The rate of change
in lead load on the population of Australia needs to be significantly
higher than 10% per year. Mainly due to gradual replacement of leaded
petrol (LP) using cars in the fleet, by those that use unleaded petrol (ULP),
lead in air is already falling at 9% per year. While lead used in petrol
accounts for only 7% of the lead used in the Australian environment, it
contributes 90% of the lead in air and thus constitutes the greatest
threat to the most sensitive population children under four years.
Sydney air receives 800 tonnes of lead from petrol
every year. Averaged, this is equivalent to over half a kilogram of lead
on every house, but the distribution is very uneven. TCC recommends
that the maximum lead concentration in LP in cities be reduced by the
end of 1993 to 0.15 g/L and that a further reduction to 0.026 g/L or
lower be introduced by the end of 1995. The octane rating of low level
leaded petrol should not be regulated by government.
Greater use of ULP
Close to 40% of ears are now using ULP, but there
are a further 30% of cars which could operate on ULP without any
reduction
in performance or any detrimental effect on the ear. The reason this
does not happen is failure by governments to produce incentives. The UK
Government caused a rapid switch from LP to ULP by creating a strong
financial incentive. We recommend that the Federal Government reduce
excise on ULP by two cents a litre and adds a corresponding margin to
LP. Such a move would be tax neutral but would act as an incentive for
owners of certain cars to switch to ULP. Further it would be an
incentive for all other cars to experiment with lead free petrol. All
cars can run on the lower octane rating ULP provided a minor adjustment
is made to the distributor timing device and an alternative valve
lubricant is used where needed. It would be possible at inspection for
registration to modify petrol inlets for those ears which can run satisfactorily
on ULP.
Lead in food
The chemical load of lead on children is already
high, and further exposure should be avoided. Four sources of food items
in the standard diet cause 91% of lead intake, 44% of the intake stems
from whole meal bread, 22% from ham, 16% from rice and 9% from tinned
pineapple. In the case of pineapple and ham the presence of lead is
directly related to lead solder. Welding has taken the place of solder
in most cans and approximately 90% of locally produced cans are welded.
Most of the imported tins are soldered. Government should legislate
immediately to ban food being sold, manufactured or imported in soldered
cans. A Western Australian survey found lead levels in food in soldered
cans to be nine times higher than those in welded cans. Current
legislation allows a Minimum Permitted Concentration [MPC] in food of
between 0.3 and 10.0 mg/kg for different categories of food. The 10
mg/kg limit is for food additives and imported food. It is recommended
that Australia adopts the UK standard of 1 mg/kg for all food excepting
baby food for which the standard should be 0.2 mg/kg. Imported food
should also conform to this standard.
Lead in fertilisers
There are no national standards for lead in
fertilisers. A National Standing Committee on Agriculture and
Resources has been established to look into impurities in fertilisers. Western Australia is the only state
which has legislation in place. Since January 1993 the sale of
fertiliser containing more than 0.05% lead or lead compounds has been
prohibited in W A. This example should urgently be followed by all
states, as it would reduce the lead content of whole meal bread and
rice, the major sources of lead in the standard diet.
Lead in drinking water
Lead solder, lead fluxes, and brass fittings are
responsible for significant levels of lead in drinking water,
particularly in first flush water. NHMRC guidelines for lead in drinking
water are 50 µg/L. This is being revised in light of the new WHO
recommendations which allow a maximum of only 10 µg/L. In Germany
and the Netherlands lead solder is prohibited. In the USA since 1992 the
90th percentile of a sampling of tap water must not exceed 15 µg/L. If
the water sampled exceeds this level the householder is required to take
remedial action. Use of plumbing supplies containing lead has been
prohibited since 1988, though do-it-yourselfers are not policed.
Australia should urgently follow the USA example.
Lead in paints & plastics
Lead is still being used for a wide number of
products in the paint industry, including primers, lead chromes and
industrial, automotive and white goods coatings. Lead driers are
used in household paints in small quantities. Paint is a non durable
product and within a few years is usually removed by scraping, sanding,
sand blasting or by the use of a blow torch. Each of these operations is
a source for lead accumulation by the operator and for those within the
vicinity of the
operation. There are satisfactory replacements for all lead products
used in paint and the industry has been moving in this direction,
slowly, since 1922. Australia should ban lead for consumer paint
products by the end of 1993 and phase out lead in all paints by 1996.
Substitutes are available for lead in PVC as a stabiliser and this use
should also be phased out by 1996.
Lead crystal & lead glazes
Lead has been used in crystal glass to enhance its
lustre, density and brilliance and allow the crystal to be cut. Lead
will leach out rapidly in contact with alcoholic beverages. This could
be a significant source of lead for a foetus or breast fed infant.
Crystal glass should have a warning on the label until substitutes are
on the market. Lead glazes are dangerous to those who work with them and
to those who use them in tableware to store acidic food or drink. An
early phase out date is recommended.
Secondary smelters
There are 79 secondary lead smelters around
Australia. Primary smelters turn ore into lead. They are usually large
and located some distance from capital cities. Secondary smelters deal
principally with reclaiming lead from batteries. They may be in heavily
populated areas, and are considered to be a source of significant
pollution. While recycling of lead batteries should be increased by a
high compulsory deposit system and by prohibiting the dumping of
exhausted batteries in land fill, the conditions of operation of
secondary smelters will have to be tightened. Facilities should be
closed if not operating to strict standards.
Incinerators
Incinerators of all kinds, industrial, municipal,
and hospital, need to be strictly regulated. A draft environment
statement for biomedical waste incineration gives maximum limits for
new incinerators in respect to total heavy metals (antimony, arsenic,
cadmium, lead and mercury) as 0.01 mg/m3 and maximum leaching rates
for ash, etc, in landfall disposal as 5 mg/L. These appear reasonable
standards, but need to apply to all incinerators - old and new.
Sewerage sludge
Guidelines for maximum levels of lead in sewerage
sludge have been recently established in a paper available from the NSW
Water Board. For lead there is a maximum concentration in sludge of 300
mg/kg. Maximum annual loading and maximum concentration in soil are also
given. At this stage there is no legislation to enforce these
guidelines. The publication unfortunately does not compare these
guideline recommendations with overseas standards.
Disincentive tax
TCC proposes a tax to be imposed on the sale of
all lead, cadmium and mercury products, based on the percentage of heavy
metal content. Money to be used for activities similar to that used by
USA Department of Housing in its extensive program to reduce children's
exposure to lead paint and remedial work in areas of high heavy metal
pollution.
|
