People who have been exposed to high concentrations of mercury, especially pregnant women and young children, are at risk of mercury poisoning which can lead to serious health complications and even death. Symptoms may arise immediately or over a long period of time depending on the dose and the duration of exposure. In most cases, symptoms take weeks, months, or even a year to surface. Mercury takes on three different forms; inorganic or organic mercury, and elemental (vaporized) mercury. Each form's toxicity symptoms slightly vary. Inorganic mercury poisoning can lead to skin irritations and blood diarrhea if ingested in large amounts. Organic mercury toxicity can lead to symptoms including muscle weakness, loss of coordination, speech, vision, and hearing impairments. A person who has been poisoned by elemental mercury may experience mood swings, insomnia, tremors, and in very serious cases respiratory failure, kidney complications, and even death.