Organic (leaded petrol) or inorganic lead is a major health hazard. Ingested, inhaled or absorbed through the skin (organic lead), lead travels in the blood throughout the body before being stored in the brain (organic lead), in the bones and teeth.

The list of the health effects of lead poisoning is long, including high blood pressure, and damage to liver, kidneys and brain. Children, including unborn children, are at particular risk as their developing body absorbs up to 50% of the lead they are exposed to, and the hand to mouth activities of children under five make them more likely to ingest lead in the form of paint or dust.

Lead poisoning in children is a documented cause of learning and attention disorders, hearing loss, slowed growth and often severe behaviour problems. Recent clinical studies have found that children with lead poisoning can exhibit symptoms similar to autism and ADD. It is both the most common and the most preventable paediatric environmental health problem in Australia.

There is also significant evidence that high lead levels may lead to atherosclerosis in adults.

Lead in paint

In Australia, up to the 1950s, paint used on houses could contain as much as 50% lead. Although the lead content of paint was limited to 0.25% by 1970 – and is currently limited to 0.1%, lead paint is still responsible for the majority of childhood and renovator lead poisoning.

Until all lead paint has been removed from houses, lead paint will be a problem and public awareness is critical to preventing our children from the devastating effects of lead poisoning. If you are planning to renovate your home, it is essential that you obtain advice on the appropriate lead safe procedures to follow.

Lead in petrol

Australia announced the phasing out of leaded petrol in Australia by the first of January 2002. Lead in petrol was the most widespread source of lead in the environment in cities and near major roads. But the lead from leaded petrol has circled the world and is found everywhere. The lead also accumulates in soil and the  dust in roof cavities.

Lead additives in petrol have been known for years to constitute a public health menace, in fact as early as the mid 1920s as revealed in the report by Jamie Lincoln Kitman entitled “The Secret History of Lead”, a strongly recommended read. Corporate interests have ensured that despite evidence of the ill effects of lead additives in petrol and the availability of safe alternatives, leaded petrol is still manufactured and constitutes 20% of petrol sold in Australia.

Australia was, with Canada, one of the countries responsible for blocking the ban on lead at the OECD meeting of July 1995, and was one of the last nations to phase out leaded petrol, after Myanmar. Leaded petrol is still used as aviation fuel (petrol-engine planes) so if you live down-wind from a general aviation airport you’re still at risk.

As is the case with paint, the legacy of some sixty-five years of leaded petrol will linger for a long time to come in the form of dust, stored as a ticking bomb in roof cavities. The removal of ceiling dust by a competent and lead aware contractor is strongly advised prior to any work involving your ceiling, from the installation of a simple skylight to an extension.

Lead in consumer products

Being cheap and having useful properties, lead is used in a wide range of consumer products, from crystal to plastics.

One of the most recently investigated uses of lead was the lead in the core of candlewicks, causing the emission of toxic vapours when burning. A federal ban declared on the 1^st September 1999 on candles fitted with a metal core wick, which contained lead, was followed by state regulation prohibiting their supply. Check the wicks of the candles you are burning at home, if you find a metal core at the centre of the wick, it most probably contains lead.

Recalls of children’s toys that have been found to have lead paint have been quite common. But toys and pencils are often still an undetected source of lead (in the paint).

Lead in Food

Depending on how food is prepared and preserved, it can contain significant amounts of lead.

A recent study found that Tumeric from a number of countries contained lead chromate, to give it a brighter yellow colour. Bangladesh has now largely ceased using lead chromate, other nations haven’t.

Choice magazine found 15% of supermarket spices contained lead.

Cattle from some ground lead rich areas have been found to be unfit for export because of high lead levels. That beef is hopefully not consumed domestically.

Lead in drinking water

Drinking water is rarely discussed in Australia as a source of lead poisoning. If your plumbing system dates from the 1930’s, lead pipes may have been used, but the concern for most homes arises out of the common use of lead-based solder on brass fittings and copper pipes up until as recently as 1989 (and later by plumbers who continued to use lead solder because it was cheaper), and on the use of lead in brass and bronze fittings. As a result of corrosion, there is a potential for the lead to leach into the water after prolonged contact. It is therefore the consumption of first flush water- the first cup of tea or baby bottle in the morning – which presents a hazard. The hazard increases significantly if the water is acidic.

Studies conducted in Sydney suburbs revealed that the lead level of first flush tap water in many cases exceeded the acceptable level set by the National Health and Medical Research Council (10 µg/L – micrograms per litre). Samples also showed excessive levels of cadmium and copper.

There is also no obligation for the manufacturers of lead-based solder to label their product as unsuitable for drinking water plumbing.

Water from rainwater tanks may also present a risk of lead contamination as a result of lead paint or flashing on roofs, lead paint or lead solder in the gutters, or lead fallout from air pollution. A study showed that one quarter of tank-water samples tested in Victoria contained more than the acceptable level of lead.

A study conducted in Perth on water collected from water boilers, urns and coffee and cappuccino machines from restaurants, offices, workplaces and schools, found that 67% of the samples contained excessive levels of lead. The probable source of the contamination was brass components in contact with hot water.

Prevalence of lead poisoning

Lead poisoning has been referred to as the “silent epidemic” because at lower levels of lead exposure, there are no or few observable symptoms. It is also probably the most undiagnosed condition affecting children and adults.

The rate of blood lead testing in Australia is incredibly low. According to Medicare statistics, in 1999, less than one person in every 2000 Australians was tested for lead in blood.

However, based on the 1994 national survey of blood lead levels in the United States, we could reasonably expect 4.5% of the population, or 90 people in every 2000 Australians to be lead poisoned (that is, above the Australian goal of 10 µg/dL or micrograms per decilitre). The US survey was published one year before their phase-out of leaded petrol and Australia was over 20 years behind before phasing out leaded petrol.

The lack of monitoring of blood lead levels is a critical factor in the public’s perception of the low prevalence of lead poisoning. It probably also explains the lack of concern about lead in various state health services.

A referral from a general practitioner is all that is required to order a blood lead test, but many GPs to this day, not only do not advise blood lead testing, but also have been known to discourage parents from testing their children. A blood lead test costs $30.60 before the Medicare rebate of 85%.

As you would expect, statistics on blood lead level testing in Australia are scarce. In 1999 there were 700 notifications in NSW of blood lead levels above 15 µg/dL (the target was for all Australians to be below this by 1998).

A 1996 blood lead survey of Sydney children found that 25% of 1-5 year olds are lead poisoned and 7% are above 15 µg/dL within 10 kms of the CBD. This translates as 1,925 children at the notifiable level, yet in 1997, there were only 10 notifications for 1-5 year old children in Central Sydney.

It is noteworthy that the NH&MRC recommends AGAINST national lead screening in its 2015 document; “Evidence on the Effects of Lead on Human Health”.