I would trust FDA/EPA over ATSDR since they do more live-animal research. ATSDR works more like a literature review, as far as I know. You still aren't likely to be hurt by it, but I get who you'd want to avoid it.
Good advice so far on the feed and nutri-drench. I've seen chicks get diarrhea from being too warm, too—they seemed to be drinking a lot of water to compensate for the temperature and it ran right through them. If you have a thermometer handy, that would be a quick thing to rule out.
You'd have...