lead wheel weights

September 3, 2010 at 12:58 pm • Posted in ALL POSTS, Lead, Science169 Comments

During a recent Washington State legislative session, a bill to ban lead wheel weights was passed. Like many well-meaning acts of the legislature, it has several serious flaws.
The purpose of the bill was reduce the amount of lead in the environment. This is an impossible goal. Between 1960 and 1975, vehicles deposited approximately 250,000,000 pounds of lead along roadways as an oxide or a bromide. These were byproducts of having three grams of tetra-ethyl lead in gasoline. Having this fact in mind, one must also recognise that every ounce of lead that we have deposited in the environment, we previously removed from the environment. It can be estimated that are 2.4 quintillion TONs of lead in the earth’s crust and it was here before man was. Ironically lead is one of several elements that is naturally increasing in concentration in the earth’s crust and will continue to do so for billions of years into the future. Remember, man did not create lead, it has always been here.
The advantages of lead wheel weights were several. Because lead is soft, it is easier to fit on the wheel. It is the least expensive high-density material available. If a lead wheel weight falls off while a car is traveling down the road, it won’t bounce off the pavement and strike other cars or their windshields causing an increase in accidents and injuries. It mashes down onto the pavement and is not easily thrown back up into traffic by tires. Lead wheel weights don’t wedge into cracks in the pavement and puncture tires causing an increase in accidents. The replacement material fails ALL of these qualities. The main reason that this was BAD legislation, is the elemental lead is relatively inert in the environment. It does NOT readily dissolve in rainwater. That is one reason it is used for battery posts. It resists corrosion from even strong mineral acids. The substitute material used in the new wheel weights meets none of these criteria. The new weights are made zinc-plated steel. I personally collected rainwater running off of zinc-plated steel and the zinc dissloved in that water was 10 times the level that is dangerous to fish and other aquatic life. When I put this statement in my report, my supervisor wouldn’t allow it because no one had ever published that fact before. I collected another sample the next time it rained from zinc-plated steel with exactly the same results. The statement was allowed in the report. Zinc-plated steel is far more dangerous to aquatic life and humans than elemental lead and the public should require that the law be reversed.
I might add that I have lost less than a dozen lead wheel weights in more than a million miles of driving.