Introduction to Toxicity

  • Etymology:
  • In Ancient Greek medical literature, the adjective 'τoξικόν' (meaning toxic) was used to describe substances that caused death or serious debilitation.
  • The word 'toxicity' draws its origins from the Greek noun 'τόξον' (meaning arc), in reference to the use of bows and poisoned arrows as weapons.
  • English-speaking American culture has adopted figurative usages for toxicity, often when describing harmful inter-personal relationships or character traits.
  • History:
  • Humans have a long history of being aware of toxicity and using it as a tool.
  • Archaeologists have found evidence of poison arrows being used as early as 72,000 to 80,000 years ago.
  • The San people of Southern Africa have preserved the practice of making poison arrows into the modern era.

Types and Measuring of Toxicity

  • Types:
  • There are five types of toxicities: chemical, biological, physical, radioactive, and behavioral.
  • Pathogens, although toxic in a broad sense, are generally called pathogens rather than toxicants.
  • Physical toxicants interfere with biological processes, such as coal dust or asbestos fibers.
  • Measuring:
  • Toxicity can be measured by its effects on the target organism, organ, tissue, or cell.
  • Population-level measures of toxicity are often used to account for individual differences in response.
  • Safety factors are added to account for uncertainties in data and evaluation processes.

Classification and Health Hazards

  • Classification:
  • Substances must be properly classified and labeled for appropriate regulation and handling.
  • The international pictogram for toxic chemicals is used to indicate toxicity.
  • Health hazards:
  • Toxicities can cause lethality to the entire body, specific organs, major/minor damage, or cancer.
  • Acute toxicity looks at lethal effects following oral, dermal, or inhalation exposure.
  • Acute toxicity is divided into five categories of severity, ranging from Category 1 requiring the least exposure to Category 5 requiring the most exposure to be lethal.
  • Skin corrosion and irritation are determined through a skin patch test analysis.
  • Other health hazards include eye damage, respiratory sensitizers, skin sensitizers, carcinogens, neurotoxicity, reproductively toxic substances, specific-target organ toxins, and aspiration hazards.

Environmental Hazards and Occupational Hazards

  • Environmental hazards:
  • Environmental hazards adversely affect the environment and can be physical or chemical.
  • Common types of environmental hazards include water contaminants (detergents, pesticides, heavy metals), soil contaminants (heavy metals, herbicides, pesticides), and air pollutants (particulate matter, carbon monoxide, sulfur dioxide).
  • The EPA maintains a list of priority pollutants for testing and regulation.
  • Occupational hazards:
  • Workers in various occupations may be at a greater risk of toxicity, including neurotoxicity.
  • The expression 'Mad as a hatter' originates from the occupational toxicity of hatters.
  • Exposure to chemicals in the workplace environment requires evaluation by industrial hygiene professionals.

Hazards for Small Businesses and Mapping Environmental Hazards

  • Hazards for small businesses:
  • Small businesses face hazards related to occupational toxicity.
  • Medical waste disposal poses specific risks for small businesses.
  • Hazards in the arts have been a concern for centuries.
  • Artists have used toxic materials and techniques without realizing their toxicity.
  • Non-toxic alternatives and safer practices have been developed in the arts.
  • Mapping environmental hazards:
  • TOXMAP is a Geographic Information System (GIS) that visually explores data from the EPA's Toxics Release Inventory and Superfund programs.
  • TOXMAP is funded by the US Federal Government.
  • Aquatic toxicity testing determines the lethality level of substances on key indicator species.
  • Fish are exposed for 96 hours, while crustacea are exposed for 48 hours.
  • The EPA defines aquatic toxicity as practically non-toxic in concentrations greater than 100 ppm.

Toxicity Data Sources

Reference URL
Knowledge Graph