Related Experiment Video
Updated: Jul 12, 2026
10:07
Assessing Teratogenic Changes in a Zebrafish Model of Fetal Alcohol Exposure
Published on: March 20, 2012
Teratogen update: inorganic arsenic
1Biomedical Research Institute, Mitretek Systems, McLean, Virginia 22102, USA. jdesesso@mitretek.org
Teratology
|August 22, 2001
Summary
Inorganic arsenic exposure via inhalation or ingestion does not pose a significant risk for developmental effects in humans. Previous studies erroneously classified inorganic arsenic as a human teratogen based on limited data and non-relevant exposure routes.
Area of Science:
- Toxicology
- Developmental Biology
- Environmental Health
Background:
- Inorganic arsenic has been historically studied for exencephaly pathogenesis in rodents using injection exposures.
- Limited epidemiological data and injection-based animal studies led to the incorrect assumption of inorganic arsenic as a human teratogen.
Purpose of the Study:
- To re-evaluate the teratogenic potential of inorganic arsenic in humans.
- To assess developmental risks by examining both historical literature and new experimental data using relevant exposure routes.
Main Methods:
- Literature review of existing human and animal studies.
- New experimental studies conducted under modern regulatory guidelines.
- Evaluation of inorganic arsenic exposure via inhalation and ingestion in animal models.
Main Results:
- Existing human epidemiological data are insufficient for risk assessment due to unconfirmed exposure and confounding factors.
- Animal studies showed malformations only with direct injection, not with inhalation or oral ingestion.
- High-dose inhalation or oral exposure, even near-lethal to dams, did not result in arsenic-related malformations.
Conclusions:
- Inorganic arsenic poses minimal risk to developing offspring via relevant exposure routes (oral, inhalation).
- Risks are negligible at environmental or occupational exposure levels.
- The classification of inorganic arsenic as a human teratogen is not supported by current evidence.
Related Concept Videos
01:36Types of Toxins
Humans continually engage with an environment rich in potentially harmful chemicals. These are introduced to our bodies through inhalation, ingestion, or skin contact. These chemicals exist in various forms, such as air and environmental pollutants, agricultural chemicals, organic solvents, and heavy metals.
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
01:26Toxic Reactions: Overview
When toxic substances penetrate the human body, they disseminate to various tissues, undergoing metabolic changes. This process yields reactive metabolites that may covalently bind with specific target molecules, resulting in toxicity.
Toxicity falls into two primary categories: local and systemic.
Local toxicity appears at the exposure site, such as protein denaturation caused by caustic substances.
In contrast, systemic toxicity requires the toxic agent's absorption and distribution,...
Toxicity falls into two primary categories: local and systemic.
Local toxicity appears at the exposure site, such as protein denaturation caused by caustic substances.
In contrast, systemic toxicity requires the toxic agent's absorption and distribution,...
01:07Teratogenicity
The ability of a drug to produce structural deformations and functional abnormalities in the developing embryo or the fetus is called teratogenicity, and the drug producing this effect is known as a teratogen. Teratogenic effects include stillbirth, miscarriage, intrauterine growth restriction, and neurocognitive delay. A teratogen may affect the embryo at different stages of development, which is important in determining the type and extent of the damage. During blastocyst formation, the early...
01:25Mutagenicity and Carcinogenicity
Mutagenicity and carcinogenicity refer to the ability of drugs to cause genetic defects and induce cancer, respectively. The International Agency for Research on Cancer (IARC) classifies agents into four groups based on their carcinogenic potential. Group 1 agents are known human carcinogens; group 2A agents are probably carcinogenic to humans; group 3 agents lack data to support their role in carcinogenesis; and group 4 includes agents for which data support that they are not likely to be...
01:27Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...
01:23Toxicity Testing in Animals
Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence...