Dose–response relationshipThe dose–response relationship, or exposure–response relationship, describes the magnitude of the response of an organism, as a function of exposure (or doses) to a stimulus or stressor (usually a chemical) after a certain exposure time. Dose–response relationships can be described by dose–response curves. This is explained further in the following sections. A stimulus response function or stimulus response curve is defined more broadly as the response from any type of stimulus, not limited to chemicals.
HormesisHormesis is a characteristic of many biological processes, namely a biphasic or triphasic response to exposure to increasing amounts of a substance or condition. Within the hormetic zone, the biological response to low exposures to toxins and other stressors is generally favorable. The term "hormesis" comes from Greek hórmēsis "rapid motion, eagerness", itself from ancient Greek hormáein "to set in motion, impel, urge on", the same Greek root as the word hormone. The term 'hormetics' has been proposed for the study and science of hormesis.
Arsenic poisoningArsenic poisoning is a medical condition that occurs due to elevated levels of arsenic in the body. If arsenic poisoning occurs over a brief period of time, symptoms may include vomiting, abdominal pain, encephalopathy, and watery diarrhea that contains blood. Long-term exposure can result in thickening of the skin, darker skin, abdominal pain, diarrhea, heart disease, numbness, and cancer. The most common reason for long-term exposure is contaminated drinking water.
Clinical officerA clinical officer (CO) is a gazetted officer who is qualified and licensed to practice medicine. In Kenya the basic training for clinical officers starts after high school and takes four or five years ending on successful completion of a one-year internship in a teaching hospital and registration at the Clinical Officers Council where annual practice licenses are issued.
