Metal poisoning symptoms may include stomach discomfort, nausea, vomiting, and diarrhea (the hallmark symptoms of most cases of acute metal ingestion). Dehydration Cardiomyopathy and irregular heartbeat are examples of cardiac problems (dysrhythmia) that can result from metal poisoning. Heavy metals can also affect the nervous system and the immune system, causing headaches, insomnia, loss of appetite, and depression. Metal poisoning can be diagnosed by checking your blood for markers of internal organ damage or excesses of certain elements in your body. Getting more than 100 micrograms of lead per deciliter of blood is unsafe; at levels below this mark, other effects may become evident. The best way to prevent metal poisoning is not to eat contaminated food or drink. Lead is only released into the environment through the recycling of old batteries and other lead items. However, even if you follow a "lead-free" lifestyle, you could still be exposed to metal toxins in other ways. For example, you might be breathing in dust particles containing metal compounds, or you might be swallowing metal fragments that have been sprayed during manufacturing processes as a lubricant or coolant. If you're eating contaminated food, you will first notice signs of metal toxicity in your digestive system. This would include abdominal pain, nausea, and vomiting. If left untreated, the effects of metal poisoning could spread to other parts of your body.