Toxic Substances, Psychological and Behavioral Conditions Related to

Each day, various toxic and nontoxic substances are absorbed into the human body through ingestion, through contact with the mucus membranes, by entering into the bloodstream, or directly through the skin. Exposure, intentional or unintentional, occurs across various contexts, such as environmental, therapeutic, or accidental, or through intentional harm. Once inside the body, substances cause a variety of effects. Some substances, like Vitamin D, are beneficial and fend off disease as well as increase health and wellness. Caffeine is a chemical that is routinely ingested by large numbers of people because it causes heightened alertness and relaxation despite having the potential for withdrawal symptoms, such as headaches, or physical problems, such as disrupted sleep or jitteriness. Recreational drugs like hypnotics are toxic substances that result ...