A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk. This term is often used synonymously in colloquial speech.
Hazards can be classified in several ways which are not mutually exclusive. They can be classified by causing actor (for example, Natural hazard or anthropogenic), by physical nature (e.g. biological or Chemical hazard) or by type of damage (e.g., health hazard or environmental hazard). Examples of with highly harmful impacts on a society are , , , , , Volcanism and . Technological and anthropogenic hazards include, for example, structural collapses, transport accidents, accidental or intentional , and release of toxic materials.
The term climate hazard is used in the context of climate change. These are hazards that stem from climate-related events and can be associated with global warming, such as wildfires, floods, droughts, sea level rise. Climate hazards can combine with other hazards and result in compound event losses (see also loss and damage). For example, the climate hazard of heat can combine with the hazard of poor air quality. Or the climate hazard flooding can combine with poor water quality.
In physics terms, common theme across many forms of hazards is the presence of energy that can cause damage, as it can happen with chemical energy, mechanical energy or thermal energy. This damage can affect different valuable interests, and the severity of the associated risk varies.
A hazard only exists if there is a pathway to exposure. As an example, the center of the Earth consists of molten material at very high temperatures which would be a severe hazard if contact was made with the core. However, there is no feasible way of making contact with the core, therefore the center of the Earth currently poses no hazard.
The frequency and severity of hazards are important aspects for risk management. Hazards may also be assessed in relation to the impact that they have.
In defining hazard Keith Smith argues that what may be defined as the hazard is only a hazard if there is the presence of humans to make it a hazard. In this regard, human sensitivity to environmental hazards is a combination of both physical exposure (natural and/or technological events at a location related to their statistical variability) and human vulnerability (about social and economic tolerance of the same location).
A natural disaster is the highly harmful impact on a society or community following a natural hazard event. The term "disaster" itself is defined as follows: "Disasters are serious disruptions to the functioning of a community that exceed its capacity to cope using its own resources. Disasters can be caused by natural, man-made and technological hazards, as well as various factors that influence the exposure and vulnerability of a community."
The US Federal Emergency Management Agency (FEMA) explains the relationship between natural disasters and natural hazards as follows: "Natural hazards and natural disasters are related but are not the same. A natural hazard is the threat of an event that will likely have a negative impact. A natural disaster is the negative impact following an actual occurrence of natural hazard in the event that it significantly harms a community.
Disaster can take various forms, including hurricane, volcano, tsunami, earthquake, drought, famine, plague, disease, rail crash, car crash, tornado, deforestation, flooding, toxic release, and spills (Oil spill, Chemical spill).
A disaster hazard is an extreme geophysical event that is capable of causing a disaster. 'Extreme' in this case means a substantial variation in either the positive or the negative direction from the normal trend; flood disasters can result from exceptionally high precipitation and river discharge, and drought is caused by exceptionally low values. The fundamental determinants of hazard and the risk of such hazards occurring is timing, location, magnitude and frequency. For example, magnitudes of earthquakes are measured on the Richter scale from 1 to 10, whereby each increment of 1 indicates a tenfold increase in severity. The magnitude-frequency rule states that over a significant period of time many small events and a few large ones will occur. Hurricanes and typhoons on the other hand occur between 5 degrees and 25 degrees north and south of the equator, tending to be seasonal phenomena that are thus largely recurrent in time and predictable in location due to the specific climate variables necessary for their formation.
Risk is a combination of hazard, exposure and vulnerability. Text was copied from this source, which is available under a For example in terms of water security: examples of hazards are droughts, floods and decline in water quality. Bad infrastructure and bad governance lead to high exposure to risk.
Risk can be defined as the likelihood or probability of a given hazard of a given level causing a particular level of loss of damage. The elements of risk are populations, communities, the built environment, the natural environment, economic activities and services which are under threat of disaster in a given area.
Another definition of risk is "the probable frequency and probable magnitude of future losses". This definition also focuses on the probability of future loss whereby the degree of vulnerability to hazard represents the level of risk on a particular population or environment. The threats posed by a hazard are:
One of the classification methods is by specifying the origin of the hazard. One key concept in identifying a hazard is the presence of stored energy that, when released, can cause damage. The stored energy can occur in many forms: chemical, mechanical, thermal, radioactive, electrical, etc.
The United Nations Office for Disaster Risk Reduction (UNDRR) explains that "each hazard is characterized by its location, intensity or magnitude, frequency and probability".
A distinction can also be made between rapid-onset natural hazards, technological hazards, and social hazards, which are described as being of sudden occurrence and relatively short duration, and the consequences of longer-term environmental degradation such as desertification and drought.
Hazards may be grouped according to their characteristics. These factors are related to geophysical events, which are not process specific:
Potentially dangerous phenomena which are natural or predominantly natural (for example, exceptions are intentional floods) can be classified in these categories:
Natural hazards can be influenced by human actions in different ways and to varying degrees, e.g. land-use change, drainage and construction. Humans play a central role in the existence of natural hazards because "it is only when people and their possessions get in the way of natural processes that hazard exists".
A natural hazard can be considered as a geophysical event when it occurs in extremes and a human factor is involved that may present a risk. There may be an acceptable variation of magnitude which can vary from the estimated normal or average range with upper and lower limits or thresholds. In these extremes, the natural occurrence may become an event that presents a risk to the environment or people. For example, above-average wind speeds resulting in a Tropical cyclone or hurricane according to intensity measures on the Saffir–Simpson scale will provide an extreme natural event that may be considered a hazard.
Although generally a natural phenomenon, earthquakes can sometimes be induced by human interventions, such as injection wells, large underground nuclear explosions, excavation of Mining, or reservoirs.
For example, technological hazards can arise from the following events:
A mechanical hazard is any hazard involving a machine or industrial process. Motor vehicles, aircraft, and pose mechanical hazards. or liquids can also be considered a mechanical hazard. Hazard identification of new machines and/or industrial processes occurs at various stages in the design of the new machine or process. These hazard identification studies focus mainly on deviations from the intended use or design and the harm that may occur as a result of these deviations. These studies are regulated by various agencies such as the Occupational Safety and Health Administration and the National Highway Traffic Safety Administration.
Engineering hazards occur when human structures fail (e.g. building or structural collapse, bridge failures, dam failures) or the materials used in their construction prove to be hazardous.
Climate hazards in the context of water include: Increased temperatures, changes in rainfall patterns between the wet and dry season (increased rainfall variability) and sea level rise.Caretta, M.A., A. Mukherji, M. Arfanuzzaman, R.A. Betts, A. Gelfan, Y. Hirabayashi, T.K. Lissner, J. Liu, E. Lopez Gunn, R. Morgan, S. Mwanga, and S. Supratid, 2022: Chapter 4: Water. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change H.-O.. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 551–712, doi:10.1017/9781009325844.006. The reason why increasing temperatures is listed here as a climate hazard is because "warming temperatures may result in higher evapotranspiration, in turn leading to drier soils".
Waterborne diseases are also connected to climate hazards.Cissé, G., R. McLeman, H. Adams, P. Aldunce, K. Bowen, D. Campbell-Lendrum, S. Clayton, K.L. Ebi, J. Hess, C. Huang, Q. Liu, G. McGregor, J. Semenza, and M.C. Tirado, 2022: Chapter 7: Health, Wellbeing, and the Changing Structure of Communities. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change H.-O.. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 1041–1170, doi:10.1017/9781009325844.009.
Climate hazards can combine with other hazards and result in compound event losses (see also loss and damage). For example, the climate hazard of heat can combine with the hazard of poor air quality. Or the climate hazard flooding can combine with poor water quality.Dodman, D., B. Hayward, M. Pelling, V. Castan Broto, W. Chow, E. Chu, R. Dawson, L. Khirfan, T. McPhearson, A. Prakash, Y. Zheng, and G. Ziervogel, 2022: Chapter 6: Cities, Settlements and Key Infrastructure. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change H.-O.. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 907–1040, doi:10.1017/9781009325844.008.
Climate scientists have pointed out that climate hazards affect different groups of people differently, depending on their climate change vulnerability: There are "factors that make people and groups vulnerable (e.g., poverty, uneven power structures, disadvantage and discrimination due to, for example, social location and the intersectionality or the overlapping and compounding risks from ethnicity or racial discrimination, gender, age, or disability, etc.)".
Biological hazards include pathogenic microorganisms, such as viruses and bacteria, epidemics, pandemics, parasites, pests, animal attacks, venom, and foodborne illnesses.
For example, naturally occurring bacteria such as Escherichia coli and Salmonella are well known , and a variety of measures have been taken to limit human exposure to these microorganisms through food safety, good personal hygiene, and education. The potential for new biological hazards also exists through the discovery of new microorganisms and the development of new genetically modified (GM) organisms. The use of new GM organisms is regulated by various governmental agencies. The US Environmental Protection Agency (EPA) controls GM plants that produce or resist pesticides (i.e. Bt corn and Roundup ready crops). The US Food and Drug Administration (FDA) regulates GM plants that will be used as food or for medicinal purposes.
Biological hazards can include medical waste or samples of a microorganism, virus or toxin (from a biological source) that can affect health. Many biological hazards are associated with food, including certain , , fungi, bacteria, and plant and seafood . Pathogenic Campylobacter and Salmonella are common foodborne biological hazards. The hazards from these bacteria can be avoided through risk mitigation steps such as proper handling, food storage, and cooking of food. Diseases can be enhanced by human factors such as poor sanitation or by processes such as urbanization.
Some harmful chemicals occur naturally in certain geological formations, such as arsenic. Other chemicals include products with commercial uses, such as agricultural and industrial chemicals, as well as products developed for home use.
A variety of chemical hazards have been identified. However, every year companies produce more new chemicals to fill new needs or to take the place of older, less effective chemicals. Laws, such as the Federal Food, Drug, and Cosmetic Act and the Toxic Substances Control Act in the US, require protection of human health and the environment for any new chemical introduced. In the US, the EPA regulates new chemicals that may have environmental impacts (i.e., or chemicals released during a manufacturing process), while the FDA regulates new chemicals used in foods or as drugs. The potential hazards of these chemicals can be identified by performing a variety of tests before the authorization of usage. The number of tests required and the extent to which the chemicals are tested varies, depending on the desired usage of the chemical. Chemicals designed as new drugs must undergo more rigorous tests than those used as pesticides.
Pesticides, which are normally used to control unwanted insects and plants, may cause a variety of negative effects on non-target organisms. DDT can build up, or bioaccumulate, in birds, resulting in thinner-than-normal eggshells, which can break in the nest. The organochlorine pesticide dieldrin has been linked to Parkinson's disease. Corrosive chemicals like sulfuric acid, which is found in car batteries and research laboratories, can cause severe skin burns. Many other chemicals used in industrial and laboratory settings can cause respiratory, digestive, or nervous system problems if they are inhaled, ingested, or absorbed through the skin. The negative effects of other chemicals, such as alcohol and nicotine, have been well documented.
Organohalogens are a family of synthetic organic molecules which all contain atoms of one of the . Such materials include PCBs, dioxins, DDT, Freon and many others. Although considered harmless when first produced, many of these compounds are now known to have profound physiological effects on many organisms including man. Many are also fat soluble and become concentrated through the food chain.
Casualties resulting from fires, regardless of their source or initial cause, can be aggravated by inadequate emergency preparedness. Such hazards as a lack of accessible , poorly marked escape routes, or improperly maintained fire extinguishers or sprinkler systems may result in many more deaths and injuries than might occur with such protections.
Chemical hazard
Radioactive or electromagnetic hazard
Thermal or fire hazard
Fire hazard
Kinetic hazard
By type of damage
Health hazard
Ergonomic hazard
Occupational hazard
Psychosocial hazard
Environmental hazard
Property
Cultural property
By status
Analysis and management
Hazard symbol
See also
External links
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