A necrosol is a type of

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows: * Human im ...

soil which is commonly found in

cemeteries A cemetery, burial ground, gravesite or graveyard is a place where the remains of dead people are buried or otherwise interred. The word ''cemetery'' (from Greek , "sleeping place") implies that the land is specifically designated as a buri ...

or other

burial sites Burial, also known as interment or inhumation, is a method of final disposition whereby a dead body is placed into the ground, sometimes with objects. This is usually accomplished by excavating a pit or trench, placing the deceased and objec ...

, and is characterized by the presence of human remains in the soil. The term necrosol was first introduced by Graf during his study of flora and vegetation at a cemetery in Berlin, Germany, in 1986. Necrosols form during the interaction of the soil with human remains and other materials included in the burial, such as

coffins A coffin is a funerary box used for viewing or keeping a corpse, either for burial or cremation. Sometimes referred to as a casket, any box in which the dead are buried is a coffin, and while a casket was originally regarded as a box for jewel ...

textiles Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...

and other human-made materials. This soil was included under urban soils in a

classification system Classification is a process related to categorization, the process in which ideas and objects are recognized, differentiated and understood. Classification is the grouping of related facts into classes. It may also refer to: Business, organizat ...

proposed by Burghardt in 1994, but are present in both urban and rural environments. Future research on Necrosols can support the field of

archeology Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landscap ...

and enhance our understanding of past burial practices.

Distribution

Necrosols are present across the globe, wherever humans have buried their dead. However, there is large variation in the natural soils which these soils developed on, based on

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologic ...

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...

, time,

parent material Parent material is the underlying geological material (generally bedrock or a superficial or drift deposit) in which soil horizons form. Soils typically inherit a great deal of structure and minerals from their parent material, and, as such, are ...

and

vegetation Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic character ...

, leading to heterogeneity among necrosols.

Classification

Necrosols are compared to a “background” or “reference” soil, which is a soil near the site but outside the burial location.This provides a reference for the type of soil that would naturally occur at the study area, without human disturbance. Necrosols are divided into two sub-groups: burial Necrosol and non-disturbed Necrosol. * Burial Necrosols have undergone direct mechanical disturbance to the

soil profile A soil horizon is a layer parallel to the soil surface whose physical, chemical and biological characteristics differ from the layers above and beneath. Horizons are defined in many cases by obvious physical features, mainly colour and texture. ...

as a result of excavating soil to make space for human remains. * Non-disturbed Necrosols are located in direct proximity to the burial site but have not undergone direct mechanical alteration from the burial, and therefore still have naturally occurring soil horizons.

Composition

The addition of human remains and other materials change the soil horizon sequence of the original soil, and alter its physical, chemical and biological properties. Soil properties or formation will vary depending on the properties of the natural soil and what the burial process is, including burial depth, number of remains buried and proximity of remains to each other. These conditions are based on specific regulatory or cultural requirements, or major death events such as

war War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using regular o ...

genocide Genocide is the intentional destruction of a people—usually defined as an ethnic, national, racial, or religious group—in whole or in part. Raphael Lemkin coined the term in 1944, combining the Greek word (, "race, people") with the Latin ...

natural disasters A natural disaster is "the negative impact following an actual occurrence of natural hazard in the event that it significantly harms a community". A natural disaster can cause loss of life or damage property, and typically leaves some econo ...

which can result in

mass graves A mass grave is a grave containing multiple human corpses, which may or may Unidentified decedent, not be identified prior to burial. The United Nations has defined a criminal mass grave as a burial site containing three or more victims of executi ...

. Necrosol characteristics are also dependent on burial practices involving how the human remains are treated before deposited in the soil. For example, the deposit of

cremated Cremation is a method of final disposition of a dead body through burning. Cremation may serve as a funeral or post-funeral rite and as an alternative to burial. In some countries, including India and Nepal, cremation on an open-air pyre i ...

remains will result in fewer

decomposition Decomposition or rot is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is e ...

processes in soil compared to a process like traditional burial. Other burial procedures, like

embalming Embalming is the art and science of preserving human remains by treating them (in its modern form with chemicals) to forestall decomposition. This is usually done to make the deceased suitable for public or private viewing as part of the funeral ...

mummification A mummy is a dead human or an animal whose soft tissues and organs have been preserved by either intentional or accidental exposure to chemicals, extreme cold, very low humidity, or lack of air, so that the recovered body does not decay furth ...

, are designed to slow the body decomposition process of the remains. Despite this variability, Necrosols have several shared diagnostic features that differentiate it from other soil types.

Mixed or disturbed horizons

In some Necrosols the natural soil horizons are absent due to disturbance as a result of the digging of graves in the soil profile. These natural horizons are mixed, and so the unique properties that characterize each horizon, like

soil texture Soil texture is a classification instrument used both in the field and laboratory to determine soil classes based on their physical texture. Soil texture can be determined using qualitative methods such as texture by feel, and quantitative methods ...

and organic matter content, will be dispersed throughout the different profiles. This feature is unique to, and what characterizes, the burial necrosols sub-group.

Presence of human remains and burial artifacts

These soils may also contain human remains and artifacts, which are materials in the soil that are created by humans such as materials from coffins, clothes or other belongings.

Higher organic carbon, phosphorus and nitrogen concentrations

All Necrosols contain high

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

and

organic carbon Total organic carbon (TOC) is the amount of carbon found in an organic compound and is often used as a non-specific indicator of water quality or cleanliness of pharmaceutical manufacturing equipment. TOC may also refer to the amount of organic c ...

. The higher levels of these nutrients compared to the natural soil nearby is due to the presence of human remains. The organic carbon, phosphorus, nitrogen and other nutrients are transferred into the soil as human remains decompose. Phosphorus is the most important soil indicator for classifying Necrosols, because it is least susceptible to change and

leaching Leaching is the loss or extraction of certain materials from a carrier into a liquid (usually, but not always a solvent). and may refer to: * Leaching (agriculture), the loss of water-soluble plant nutrients from the soil; or applying a small amou ...

. High phosphorus concentrations come from the addition of human remains to the soil. This occurs through

chemical weathering Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement ...

of soft tissue and bone in

inhumation Burial, also known as interment or inhumation, is a method of final disposition whereby a dead body is placed into the ground, sometimes with objects. This is usually accomplished by excavating a pit or trench, placing the deceased and objec ...

, or the addition of ash from

cremation Cremation is a method of Disposal of human corpses, final disposition of a Cadaver, dead body through Combustion, burning. Cremation may serve as a funeral or post-funeral rite and as an alternative to burial. In some countries, including India ...

. In fact, the reports in 1815 from the

Battle of Waterloo The Battle of Waterloo was fought on Sunday 18 June 1815, near Waterloo, Belgium, Waterloo (at that time in the United Kingdom of the Netherlands, now in Belgium). A French army under the command of Napoleon was defeated by two of the armie ...

indicated that bones from the war, high in phosphorus, were taken from the site and ground up to use as fertilizer back in England.

Presence of toxics and heavy metals based on burial preparation

Depending on the burial procedure, human remains and artifacts may bring the addition of certain chemicals to the soil. This includes higher concentrations of

heavy metals upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals are generally defined as ...

which come from

paints Paint is any pigmented liquid, liquefiable, or solid mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture. Paint can be made in many ...

metals A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

on artifacts like coffins. Additionally, chemicals used on human remains during burial processes, like

formaldehyde Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section F ...

, may be present in the soils within the first 14 weeks of burial.

References

Pedology Types of soil {{soil-stub