Table of Contents
What are two things that can affect how toxic a substance is to a person?
What Factors Influence Toxic Exposure Levels?
- Point Of Entry. A substance can only affect a person or animal by coming into physical contact with the body.
- Dosage and Toxicity. These are perhaps the two most important factors determining the hazard presented by any given substance.
- Rate Of Removal.
- Biological Variation.
What makes a substance poisonous?
All chemicals can cause harm. When only a very large amount of the chemical can cause damage, the chemical is considered to be practically non-toxic. When a tiny amount is harmful, the chemical is considered to be highly toxic.
What are the factors that determine when a substance is toxic and unfit for human consumption?
The toxicity of a substance usually depends on the following factors:
- Form and innate chemical activity.
- Dosage , especially dose -time relationship.
- Exposure route.
- Life stage, such as infant, young adult, or elderly adult.
- Ability to be absorbed.
What is the most toxic substance in environment?
1. Botulinum toxin. Scientists differ about the relative toxicities of substances, but they seem to agree that botulinum toxin, produced by anaerobic bacteria, is the most toxic substance known. Its LD50 is tiny – at most 1 nanogram per kilogram can kill a human.
What type of interaction between two chemicals causes one chemical not toxic to become more toxic?
In toxicology, synergism refers to the effect caused when exposure to two or more chemicals at one time results in health effects that are greater than the sum of the effects of the individual chemicals.
What is the difference between toxic and very toxic?
Within this division, there are two additional subdivisions that separate “Toxics” and “Very Toxics”. The “Very Toxics” are D1A; the “Toxics” are D1B. In this division, the primary difference between D1A and D1B is acute toxicity (e.g. LD50, LC50).
What are the effect of harmful substance?
What are the hazards? Some substances can cause asthma or other diseases, including cancer. Many can damage the skin, and some can cause serious long-term damage to the lungs. The effect can be immediate, such as dizziness or stinging eyes, or can take many years to develop, such as lung disease.
What three factors affect the toxicity of a substance?
Toxicity of chemicals is greatly affected by various factors pertaining to their exposures to the organisms. Some of the important factors related to exposures are: (i) exposure routes, (ii) exposure duration, and (iii) exposure systems.
What is highly toxic material?
Examples of highly toxic chemicals include: hydrazine, mercuric chloride, osmium tetroxide, white or red phosphorus, sodium azide, and sodium cyanide. The median lethal dose (LD50) for a dangerously toxic chemicals is oral rat LD50 of less than 1 mg/kg of body weight.
What are the two types of toxicity?
The two types of toxicity are acute and chronic. Acute toxicity of a pesticide refers to the chemical’s ability to cause injury to a person or animal from a single exposure, generally of short duration. The four routes of exposure are dermal (skin), inhalation (lungs), oral (mouth), and eyes.
What type of interaction between two chemicals produces an effect that is equal to their individual effects taken together?
Which term indicates that the combined effect of exposures to two or more chemicals that is greater than the sum of their individual effects?
Synergism indicates that the combined effect of exposures to two or more chemicals is greater than the sum of their individual effects.
How are metals harmful to the human body?
The toxic effects of these metals, even though they do not have any biological role, remain present in some or the other form harmful for the human body and its proper functioning. They sometimes act as a pseudo element of the body while at certain times they may even interfere with metabolic processes.
What is the ionic mechanism of lead toxicity?
The ionic mechanism of lead toxicity occurs mainly due to the ability of lead metal ions to replace other bivalent cations like Ca 2+, Mg 2+, Fe 2+ and monovalent cations like Na +, which ultimately disturbs the biological metabolism of the cell.
Which is the most dangerous element on the periodic table?
Radioactivity: The obviously dangerous elements are those which are highly radioactive. While radioisotopes can be made from any element, you’d do well to steer clear of any element from atomic number 84, polonium, all the way to element 118, oganesson (which is so new it was only named in 2016).
What are the effects of exposure to heavy metals?
Metal toxicity depends upon the absorbed dose, the route of exposure and duration of exposure, i.e. acute or chronic. This can lead to various disorders and can also result in excessive damage due to oxidative stress induced by free radical formation.