GM logoParts containing mercury were used for items like anti-lock brakes sensors and hood light switches until 2004. The following year, an umbrella organization called End of Life Vehicle Solutions (ELVS) began retrieving the mercury switches from junked cars, its activities paid for by contributions from automakers.

According to The Detroit News, General Motors gave to ELVS until 2009, when it declared bankruptcy. Its obligations were then transferred to Motors Liquidation Company, which didn't contribute to ELVS, so ELVS didn't have the funds to retrieve and dispose of the toxin. And even though it was claimed that 54 percent of Cash-for-Clunkers cars were GM models, post-bankruptcy GM said it had no obligation to contribute – and according to bankruptcy law, it was right.

But that didn't stop efforts from states trying to keep junked cars from seeping mercury into their air and land. Twelve states brokered a deal with 'Old GM' to have it contribute $2.845 million to a trust to provide for mercury parts removal, which is "in addition to an earlier commitment by the 'New GM' to make a similar payment."