Скачать или смотреть Toxicity of Physical and chemical agents; Common Types, Mechanisms of Toxicity

toxicity of physical and chemical agents refers to their ability to cause harm to living organisms—especially humans—through various mechanisms depending on their nature, exposure route, and duration. These agents are central to the study of toxicology, which explores how substances interact with biological systems to produce adverse effects.

⚗️ Chemical Agents
Chemical agents include synthetic and natural substances that can be toxic when inhaled, ingested, absorbed through the skin, or injected.

🔬 Common Types
Heavy metals (lead, mercury, arsenic)

Solvents (benzene, toluene)

Pesticides (organophosphates, carbamates)

Pharmaceuticals (when misused or overdosed)

Industrial chemicals (formaldehyde, phosgene)

🧠 Mechanisms of Toxicity
Cellular damage via oxidative stress or DNA mutation

Enzyme inhibition disrupting metabolic pathways

Neurotoxicity affecting brain and nerve function

Carcinogenicity leading to cancer development

🧪 Factors Influencing Chemical Toxicity
Dose: “The dose makes the poison” (Paracelsus)

Duration: Acute vs. chronic exposure

Route of entry: Inhalation, ingestion, dermal

Individual susceptibility: Age, genetics, health status

🌡️ Physical Agents
Physical agents are forms of energy or environmental conditions that can cause harm without being chemical substances.

⚡ Examples
Radiation (ionizing: X-rays, gamma rays; non-ionizing: UV)

Noise (industrial, environmental)

Vibration (from machinery or tools)

Extreme temperatures (heatstroke, hypothermia)

Pressure changes (barotrauma in diving or aviation)

🧠 Health Effects
Radiation: DNA damage, cancer, burns

Noise: Hearing loss, stress, sleep disruption

Heat: Dehydration, organ failure

Cold: Frostbite, slowed metabolism

🧩 Interactions & Combined Effects
Sometimes physical and chemical agents interact synergistically, amplifying toxicity:

Radiation + chemical exposure may increase cancer risk



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