Polysytrene factories and hypothetical health concerns Background/Research so far

I'm actually not much of a chemist at all; but I'm doing research for a book I'm writing.

The events of the story begin from a factory that produces/supplies jewel cases for cheap CDs. This factory then pollutes the city's water by reckless dumping. Basically I'm a psychopath and I want to give my city's citizens harmful affects that are revealed after 15 years. Maybe their livers melt or something.

I learned that these jewel cases are made from a plastic called polystyrene.

From this website, I found this:


  Polystyrene (PS, #6): styrene, ethylbenzene, benzene, ethylene, carbon
  tetrachloride, polyvinyl alcohol, antimony oxide, and tert-butyl
  hydroperoxide, bensoquinone


I thought maybe the pollution could be caused by leftover ingredients for the plastic used in the process.

I then examined carbon tetracholoride ($\ce{CCl4}$). This seems really harmful and may cause long term damage if accidentally ingested, especially to the liver. So this sounded exactly what I am looking for. However, I'm not sure how realistic/true this is because further research showed that $\ce{CCl4}$ is, in fact, so harmful that it's rarely used anymore. So it seems like it may be unrealistic to use in the story, because maybe the above article is inaccurate and $\ce{CCl4}$ is not that prevalent.

Benzene also is an obvious one, but it seems to mostly cause blood cancer (leukemia) through ingestion. For reasons that occur later in the story, isn't really isn't going to work. I was kind of looking for a specific organ failure/problems/cancer and not those that effect blood and/or skin.

Ethylene also looks promising because it's so close to ethylene gylcol, and ethylene glycol would really mess people up (it is my understanding is that it's basically antifreeze). But further research indicates that ethylene isn't very harmful at all.

I also thought of cleaning agents for polystyrene instead of actual ingredients. And it sounds like $\ce{CCl4}$ comes into play again because it's used as a "dry solvent," according to Wikipedia in "Historical Uses".

Question

I'm starting to fall short in research and I want my story to be as facutal as possible. So I'm wondering which chemicals would be the most realistic in terms of use in the practical manufacture of polystyrene that could be dumped a really cause problems health-wise for a city.
It is good to see the some authors want to build realism into their fiction: this clearly isn't common. And you have done extensive research already.

The problem is that industrial chemistry is very heavily regulated. So, while it is common for dangerous substances to be used, it is rare to find places where they can plausibly be misused. And the standards for harmfulness are very low. Even some things at the harmful end of the official scale are not that harmful.

The biggest problem you will have when it comes to realism isn't really to do with polystyrene manufacture at all. A factory that makes products with polystyrene won't usually make its own polystyrene but will buy in the plastic raw material as polystyrene beads which can be mixed with other ingredients (like colours) and melted in moulding machines which produce the product. So none of the chemicals used to manufacture the plastic will be used anywhere while making products from the plastic.

If you were to assume that the raw polystyrene was made locally (which isn't that realistic) then you might find plenty of chemicals that could be misused as you have already realised. CCl4 is one of the best candidates but i rarely used any more. Benzene is used in manufacture so is also plausible; styrene (the monomer that is used to make the plastic) is also nasty and possibly the best candidate you haven't considered.

However, if you want to stick with broad realism and a story that uses plausible things associated with a jewel case factory, then you need to consider a different approach. But it might be easier because you can make some things up that even experienced experts can't question. You could, for example, imagine that your factory adds some special ingredient to its products to create unusual colours or effects (maybe the cases glow in the dark, are unusually strong or contain inks that allow patterns to be printed deep into the plastic by lasers). The ingredients to create this effect could be anything you want (and you probably don't have to be too explicit about exactly what it is: give it an obscure acronym). This ingredient could plausibly have any bad properties you want without being unrealistic. Possibly the product will have been invented recently to give the products a special edge and nobody else has yet observed the side effects.