The toxicity of a substance usually depends on the following factors:
- Form and innate chemical activity.
- Dosage , especially dose -time relationship.
- Exposure route.
- Species.
- Life stage, such as infant, young adult, or elderly adult.
- Gender.
- Ability to be absorbed.
- Metabolism.
- 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 are the factors that determine toxicity?
How does the distribution of toxicants affect the body?
How does gut microbiota affect drugs?
Why is exposure important in determining toxicology?
How sensitive are male rats to DDT?
How do environmental chemicals affect the microbiome?
Which is more toxic, parathion or nitrosamine?
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What are the 4 factors that affect the extent to which a substance is poisonous?
The toxicity of a substance depends on three factors: its chemical structure, the extent to which the substance is absorbed by the body, and the body's ability to detoxify the substance (change it into less toxic substances) and eliminate it from the body.
What factors influence the level of toxicity?
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 are the four types of toxicity?
The four toxicity categories, from one to four are:Toxicity category I is Highly toxic and Severely irritating,Toxicity category II is Moderately toxic and Moderately irritating,Toxicity category III is Slightly toxic and Slightly irritating,Toxicity category IV is Practically non-toxic and not an irritant.
How are toxicity levels determined?
Toxicity can be measured by the effect the substance has on an organism, a tissue or a cell. We know that individuals will respond differently to the same dose of a substance because of a number of factors including their gender, age and body weight. Therefore a population-level measure of toxicity is often used.
What is the most important determinant of toxicity?
The dose of a substance is the most important determinant of toxicity. Dose by definition is the amount of a substance administered at one time. The most important are the number of doses, frequency, and total time period of the treatment.
What 4 things are essential to controlling exposure to toxic substances?
Use chemical protective clothing.Wear respiratory protection. [ See the Respiratory Protection Safety and Health Topics page]Use gloves.Wear eye protection.
How do you identify toxicity in humans?
What Is a Toxic Person?You feel like you're being manipulated into something you don't want to do.You're constantly confused by the person's behavior.You feel like you deserve an apology that never comes.You always have to defend yourself to this person.You never feel fully comfortable around them.More items...•
What are the four steps that define the mechanisms of toxicity?
First, the toxicant is delivered to its target or targets (step 1), interacting with endogenous target molecules (step 2a) or altering the environment (step 2b), triggering perturbations in cell function and/or structure (step 3), which initiate repair mechanisms at the molecular, cellular, and/or tissue levels (step 4 ...
What are the 3 types of toxicity?
Toxic agents may be: chemical (such as cyanide), physical (such as radiation) and biological (such as snake venom). Toxic substance is simply a material which has toxic properties. A toxic agent is anything that can produce an adverse biological effect. It may be chemical, physical, or biological in form.
What is the basic rule of toxicity?
It relies on the concept that a dose, or a time of exposure (to a chemical, drug, or toxic substance), will cause an effect (response) on the exposed organism. Usually, the larger or more intense the dose, the greater the response, or the effect.
What does toxicity level mean?
A toxic LOC tells you what level (threshold concentration) of exposure to a chemical could hurt people if they breathe it in for a defined length of time (exposure duration). Generally, the lower the toxic LOC value for a substance, the more toxic the substance is by inhalation*.
What are the two types of toxicity measurement test?
2" Subchronic toxicity tests occur over a period of weeks, while chronic effects tests measuring long-term exposure last several months.
What are the causes of toxicity?
Inhaling (breathing in) contaminated air is the most common way that workplace products enter the body. Some chemicals, when in contact with the skin, can seep through the skin. Less commonly, workplace chemicals may be swallowed, for example from contaminated food or cigarettes. The eyes may also be a route of entry.
What are the 3 types of toxicity?
Toxic agents may be: chemical (such as cyanide), physical (such as radiation) and biological (such as snake venom). Toxic substance is simply a material which has toxic properties. A toxic agent is anything that can produce an adverse biological effect. It may be chemical, physical, or biological in form.
Factors which Affect Overall Toxicity in the Environment
ADVERTISEMENTS: In the environment, the concentration, transport, transformation and fate of a chemical are affected by several factors. Factors which affect overall toxicity may be described under four headings; 1. Factors Related to Chemical: ADVERTISEMENTS: Physico-chemical properties: The physico-chemical properties of a compound that are considered important include its molecular ...
Factors affecting toxicity
Factors assocaiated with treatment Dose Volume of solvent Type of exposure - acute –usually results with high concentration at the target site which may cause acute or delayed effects
Factors affecting toxicity (Chapter 5) - Environmental Toxicology
Environmental Toxicology - March 2002. To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account.
Factors Influencing Toxicology - Columbia University
Thalidomide ("Contergan") was sold in Europe in the late 1950s and early 60s as a sedative and a drug to prevent morning sickness in pregnant women. Shortly after, it was shown to cause severe malformations (missing limbs) in the fetus. It is thought now, that only one form of thalidomide acts as a teratogen its mirror image (enantiomer) is thought to have the sedative effect, and possibly ...
Toxicology: Factors Affecting Toxicity - Indian Agricultural Statistics ...
The physical state – whether solid, coarse powder or fine powder or solution – finely divided soluble forms are more toxic.
Summary
In Chapter 2, we saw that the exposure of organisms to toxic agents in the environment may result in adverse effects if the exposure concentration and time exceed certain thresholds. A primary goal of toxicologists is to establish a quantitative relationship between toxic exposure and degree of effect.
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11th International Symposium on Process Systems Engineering
Hengchong Li, ... Yu Qian, in Computer Aided Chemical Engineering, 2012
Life Cycle Assessment in Nanotechnology, Materials and Manufacturing
Sergio Durante, ... Nicola Ridgway, in Micromanufacturing Engineering and Technology (Second Edition), 2015
26th European Symposium on Computer Aided Process Engineering
Arturo Álvarez del Castillo-Romo, ... Alicia Román-Martínez, in Computer Aided Chemical Engineering, 2016
Energy Production
Toxic substances on the human environment are the core concerns for this category. In the working environment, the health risks are not included in this category.
Life Cycle Assessment of Ammonia Production Methods
Vishavdeep Singh, ... Marc A. Rosen, in Exergetic, Energetic and Environmental Dimensions, 2018
Introduction
Young et al. (2000) developed environmental impact factors calculated using the Waste Reduction (WAR) algorithm.
Systems Analysis & Life Cycle Analysis
The LCI determines which chemicals are associated with a product and the magnitude of the source of those chemicals normalized to the FU. The source estimation traditionally takes the form of an estimate of chemical emissions to specific medium in the outdoor environment (e.g., air, water, soil) across the life cycle stages of a product or service.
How is toxicity measured?
Toxicity can be measured by the effect the substance has on an organism, a tissue or a cell. We know that individuals will respond differently to the same dose of a substance because of a number of factors including their gender, age and body weight. Therefore a population-level measure of toxicity is often used.
How to test for toxic shellfish?
The standard method to test for toxins and toxicity levels in shellfish has been the mouse bioassay. This consists of injecting extracts of shellfish into mice to determine the presence of substances toxic to humans.
Why do mice die in shellfish bioassay?
Sometimes, the mice die for reasons other than toxins in the shellfish, and an industry is shut down when in fact the shellfish are fine. Also, some people object to using animals in this way.
What is the median lethal dose?
This is defined as the dose required to kill half the members of a specific animal population when entering the animal’s body by a particular route. LD 50 is a general indicator#N#9#N#of a substance’s toxicity within a short space of time. It is a measure of acute toxicity.
Is there a method for testing for toxins in seafood?
The Cawthron Institute in Nelson has been instrumental in developing a method using liquid chromatography-mass spectrometry (LC-MS) to monitor toxins in seafood.
How to diagnose acute toxicity?
Acute toxicity is more easily diagnosed, as the symptoms will follow the one-time administration of medication. Blood tests can also screen for levels of the medication in the person's bloodstream.
What is toxicology in medicine?
on August 28, 2020. Getty Images. Toxicity refers to how poisonous or harmful a substance can be. In the context of pharmacology, drug toxicity occurs when a person has accumulated too much of a drug in his bloodstream, leading to adverse effects on the body. 1 Drug toxicity may occur when the dose is given is too high or ...
Can toxicity occur from over-ingestion?
Occurrence. Drug toxicity can occur as a result of the over-ingestion of a medication—having too much of a drug in a person's system at once. This can happen if the dose taken exceeds the prescribed dose, either intentionally or accidentally. With certain medications, drug toxicity can also occur as an adverse drug reaction (ADR).
Is it harder to diagnose chronic toxicity?
Chronic toxicity is harder to diagnose . Stopping the medication and then "re-challenging" it, later on, is one method of testing whether the symptoms are caused by the medication. This method can be problematic, however, if the medication is essential and doesn't have an equivalent substitute.
Is lithium a toxic drug?
In some cases, such as with the drug lithium, the threshold between what is an effective dose and what is a toxic dose is very narrow. A therapeutic dose for one person might be toxic to another person. 2 Drugs with a longer half-life can build up in a person's bloodstream and increase over time.
Can a drug cause toxicity?
With certain medications, drug toxicity can also occur as an adverse drug reaction (ADR). In this case, the normally given therapeutic dose of the drug can cause unintentional, harmful and unwanted side effects.
Is lithium a chronic toxicity?
In the case of lithium, different symptoms can occur depending on whether the toxicity is acute (one-time ingestion by someone who has not been taking it) or chronic (the effect of a slow buildup of the medication to toxic levels by someone who is taking it as prescribed).
What are the downsides of the ‘factors of humans’ perspective on human factors?
Many of the downsides of the ‘factors of humans’ perspective on human factors are addressed by the ‘factors affecting humans’ perspective. But some other issues remain. One concerns the difficulty in understanding the influence of multiple , interacting factors affecting humans in the real work context.
What are the physical functions of humans?
physical functions and qualities such as strength, speed, accuracy, balance and reach ; physical, cognitive and emotional states such as stress and fatigue). The following well-known definition from the UK Health and Safety Executive (1999) seems to emphasise the ‘factors that affect humans’ kind of human factors:
What are the aspects of human functions?
aspects of human functions, qualities and states that affect performance (e.g., cognitive functions such as attention, detection, perception, memory, judgement and reasoning, decision making, motor control, speech; physical functions and qualities such as strength, speed, accuracy, balance and reach;
Is the factor affecting human a positive or negative factor?
Additionally, when applied in a safety management context, the ‘factors affecting humans’ perspective is almost entirely negative. From a safety perspective, the positive influence of ‘factors affecting humans’ (and indeed ‘factors of humans’ and ‘the human factor’) is mostly ignored.
Is the direction of influence of factors affecting humans linear?
The direction of influence of ‘factors affecting humans’ is often assumed to be one-way ( linear), as per the HSE definition above. But people also influence these influencing ‘factors’ in the context of a sociotechnical system.
What are the factors that determine toxicity?
The toxicity of a substance usually depends on the following factors: Form and innate chemical activity. Dosage, especially dose -time relationship. Exposure route.
How does the distribution of toxicants affect the body?
A major determinant of whether a toxicant will damage cells is its lipid solubility. If a toxicant is lipid-soluble, it readily penetrates cell membranes.
How does gut microbiota affect drugs?
There is awareness that the gut microbiota can impact the toxicity of drugs and other chemicals. For example, gut microbes can metabolize some environmental chemicals and bacteria-dependent metabolism of some chemicals can modulate their toxicity.
Why is exposure important in determining toxicology?
Some chemicals may be highly toxic by one route but not by others. Two major reasons are differences in absorption and distribution within the body. For example:
How sensitive are male rats to DDT?
Studies in animals also have identified gender-related differences. For example: Male rats are 10 times more sensitive than females to liver damage from DDT. Female rats are twice as sensitive to parathion as are male rats.
How do environmental chemicals affect the microbiome?
Also, environmental chemicals can alter the composition and/or the metabolic activity of the gastrointestinal bacteria, thu s contributing in a meaningful way to shape an individual's microbiome. The study of the consequences of these changes is an emerging area of toxicology.
Which is more toxic, parathion or nitrosamine?
Some chemicals are more toxic to infants or the elderly than to young adults. For example: Parathion is more toxic to young animals. Nitrosamines are more carcinogenic to newborn or young animals. Figure 3.2. 3. An individual's life stage can impact that person's response to toxicants.
Lethal Dose
- One such population-level measure is the median lethal dose, LD50 (lethal dose, 50%). This is defined as the dose required to kill half the members of a specific animal population when entering the animal’s body by a particular route. LD50is a general indicator of a substance’s toxicity within a short space of time. It is a measure of acute toxicit...
Fixed-Dose Procedure
- In 1992, the fixed-dose procedure (FDP) was proposed as an alternative test to LD50. It uses fewer animals, and there is less pain and suffering. In this procedure, the test substance is given at one of four fixed-dose levels (5, 50, 500 and 2,000 milligrams per kilogram) to five male and five female rats. When a dose produces clear signs of toxicity but no death is identified, the chemica…
Parts Per Million
- Some chemicals can cause toxicity at very low doses, so it is important to understand how low doses compare to one another. Parts per million (ppm), parts per billion (ppb) and parts per trillion (ppt) are the most commonly used terms to describe very small amounts of substances. A ppm of a chemical in water means that, in a million units of water, there would only be one unit of the ch…
Mouse Bioassay For Shellfish
- The standard method to test for toxins and toxicity levels in shellfish has been the mouse bioassay. This consists of injecting extracts of shellfish into mice to determine the presence of substances toxic to humans. After injection, if two out of three mice die within 24 hours, the sale of that particular shellfish is prohibited. Tests are then conducted systematically at least once a …
Using Liquid Chromatography-Mass Spectrometry
- In 2000, the Cawthron Institute in Nelson designed a way to test for toxicity levels in shellfish using liquid chromatography-mass spectrometry (LC-MS). Using LC-MS, the actual toxin can be identified (unless it’s a new toxin that hasn’t been identified before) as well as the level of its toxicity. This test means that toxins can be detected and monitored using chemical procedures i…