In addition to the other rigors of their jobs, workers who transport toxic waste face potential health effects. Some of these health effects are well understood, and others are not. These potential effects could have consequences long after the worker is finished doing their job. These risks are real and serious, and merit additional pay.
If the workers who are doing the transport normally do not haul toxic waste, I would hope so. They should also receive the appropriate training to handle hazardous material incidents or accidents when they happen. Presumably, one who transports toxic waste for a living already gets paid more, and would have this training.
The majority of workers in this industry already receive extra pay for doing this type of job and I think they well deserve it, over time these workers may get some health effects from doing this job that could shorten their lives or lower the quality of their life so I think some extra pay for the extra risk is well deserved.
The transport of toxic materials requires special experience in regards to the handling of the equipment and maintenance. More importantly, the transporters should be required to undergo special training that addresses what to do when something goes wrong. This training would result in a certificate required for the transportation. Earning such a certificate should be compensated, along with the risk.
Hazmat drivers are typically paid at a higher rate than drivers who are not licensed to transport hazardous materials. They absolutely deserve the higher rates of pay. They have gone the extra mile to obtain the required authorizations and they are training requirements are far more exhaustive that their non-hazmat counterparts. Their responsibilities far outweigh those of a standard driver. They are required to receive training on chemical safety, spill response, specialized documentation, and security. This is in addition to their demonstrated competency at driving a commercial vehicle. Why wouldn't they earn more? Advanced achievements and certifications typically result in higher salaries, regardless of the field of expertise. It is in everyone's best interest to have highly qualified individuals in this role.
There is no reason why workers transporting toxic waste should receive extra pay. As long as the transport company did everything legally per environmental and legal requirements, then there is nothing out of the ordinary that would be required of the workers transporting it. It would be different if they were putting themselves at risk.