Workers' compensation was set up during a time when most work injuries were trauma-related. Today, deaths from occupational illness far outnumber deaths from work injuries. But the system often fails workers who become ill at work because of acute or chronic exposure to a toxin or other dangerous work condition.
Part of the problem is that the nature of illness related to toxic exposure doesn't always cooperate with regulations governing workers' compensation claims. An exposure-related illness could take years for symptoms to manifest, at which time the statute of limitations to file a claim may have run out.
Another challenge for illness-related claims is the burden of proof. Proving that an illness was caused by exposure to a work condition, and not by exposure to something outside of work can be difficult, especially when symptoms take a long time to show up. Contrast this to a scenario involving injuries sustained after an explosion, where the cause an effect are rather obvious, and it's clear that the workers' compensation system works better for some conditions than others.
This is not to say that filing a workers' compensation claim is futile in the case of occupational illness. It does, however, highlight the need for workers to seek medical treatment early when injured, and document all known exposures and injuries at work as soon as they happen. It also underscores the need for workers who have been injured or become ill at work to have an experienced workers' compensation attorney who is familiar with how insurance companies fight, and can gather adequate evidence and expert testimony to create the strongest possible case.