Case Report: Impact of Shallow Burial on Differential Decomposition

Introduction

Routine decomposition starts immediately after death via autolysis and putrefaction. ${1,2}$
Burial environments affect decomposition rates.
Soft tissues liquefy and disintegrate unless microbial growth is slowed or stopped.
Differential decomposition can occur, where some soft tissues survive due to specific conditions. ${3,4}$
Mummification involves moisture loss and tissue desiccation, arresting decay. ${5}$
Terminology in post-mortem reports can be imprecise.
'Mummification' derives from the Persian word 'mu´miya', meaning bitumen.
Technically, mummification should refer to artificial preservation, but it's broadly used for tissue desiccation or soft tissue survival by any mechanism. ${6}$
Contrasting soft tissue survival types: desiccation and adipocere formation. ${6,7}$
Desiccation: dehydration of soft tissues, skin becomes dark, dry, and leathery.
- Occurs in areas exposed to airflow or dry burial conditions, limiting putrefaction.
- A desiccated body can remain preserved for years in a stable environment. ${1,2,4,6–9}$
Adipocere Formation: subcutaneous fat transforms into a grey-white lipid mixture.
- Over time, becomes a hard, brittle shell, retarding decomposition. ${1,10,11}$
- Chemical process: hydrolysis and hydrogenation of adipose fats.
- Composition: saturated fatty acids (myristic, palmitic, stearic) with hydroxyl and oxo-fatty acids. ${11,12}$
- Results from bacterial action under anaerobic conditions with sufficient moisture. ${1,11–16}$
- Like desiccation, adipocere can persist for years if the environment is stable, but can undergo further decomposition under certain conditions. ${11,12,17}$
Desiccation and adipocere are typically contrasting conditions, but slight adipocere formation is common in desiccation.
- Internal body water can hydrolyze fat, aiding tissue dehydration.
- Dehydration accompanies adipocere formation when little or no external water is available (atypical condition). ${4,10,12,18,19}$
- Most adipocere cases are linked to water immersion, wet graves, or damp vaults. ${19}$
Cotte et al. ${20}$ found adipocere as a main degradation product in desiccated skin of an Egyptian mummy.
Differential decomposition (decay, desiccation, adipocere) is rare in temperate climates.
One case described a body on a beach in Scotland, found 8 months post-disappearance, partly decomposed, mummified, with some adipocere. ${21}$
This study examines taphonomic variables in a case with marked differential decomposition featuring both desiccation and adipocere formation.

Case Report

Remains of a 65-year-old adult male found in private coniferous woodland in Belgium during spring.
No disturbance to the remains before police involvement.
The deceased had been buried naked, lying on its left side in a semi-flexed position and partly covered with brush.
Grave dimensions: 110 by 136 cm, depth of 30–42 cm.
Soil not compacted; the victim’s right leg protruded.
Right arm and part of the temporal bone were also visible.
Woodland: conifers spaced 3–4 m apart, with dead wood, needles, and brush undergrowth.
Remains excavated forensically.
Extensive soft tissue remained; only a small part of the temporal bone was skeletonized.
Adipocere covered the head, neck, right shoulder, upper torso, and left leg.
The right leg was desiccated: reddish-brown, hard, and dry tissue.
The rest of the torso and the arms looked fresh.
Blue staining from body exudates visible in the surrounding soil.
No noticeable strong odor.
Rodent gnawing on temporal bone and distal ends of left metacarpals.
Phalanges of this hand were absent, likely taken by scavengers.
No other signs of carnivore activity.
Little entomological evidence: few larvae and pupae of Calliphora vicina only.
Autopsy and odontological study performed.
The deceased went missing about 7 months earlier.
The body was relatively intact due to delayed putrefaction; primary bloat stage (gas accumulation without rupturing or purging).
Diffuse gas accumulation.
Spleen, suprarenal glands, and testes were totally decomposed.
The brain was liquefying, but other organs and body were relatively well-preserved, with muscle structure intact.
Epidermis had started to loosen, but hair was still anchored.
Pubic hair was absent due to epidermis loss
No definitive cause of death.
Neither the medical examiner nor forensic entomologist could determine the exact time of death.
The entomologist's minimal post-mortem interval was about 3 months.
Assumed that differential preservation influenced insect activity, because a large assemblage of different insects on the body would normally be expected.
The suspect confessed to smothering the victim; the wife confirmed the timeframe.
The suspect stated the body was undressed 12 hours post-death, covered with plastic bags, rolled in a mattress, and kept for 36–48 hours in a windowless room, then transported to the burial place.

Analysis and Discussion

Objective assessment using the Soft Tissue Index and Visceral Index (Aufderheide ${6}$ ) to avoid variable terms like "well preserved" or "liquefied".
Soft Tissue Index: estimates present skeleton or soft tissue by assigning numerical units to major body parts and multiplying the total sum by four.
Visceral Index: estimates visceral organ preservation, includes hair, and assigns ten points if present.
In this case, the Soft Tissue Index was 96%, and the Visceral Index was 65%.
After 7 months of burial, unique taphonomic factors led to localized adipocere and desiccation.
Preservation of soft tissue is a competition between decay and preservation, influenced by various variables. ${7,22}$
Significant differences can occur within the same cadaver, highlighting the importance of site-specific information. ${1,3}$

Pre-burial conditions

Desiccation is expected in dry, warm, undisturbed places (closed rooms, cupboards, attics).
Dry concealment can lead to adipocere if internal body water is sufficient for hydrolysis. ${18,19}$
In this case, the body was left for at most 48 hours in a dark room, covered with plastic bags and rolled in a mattress.
48 hours is likely too short to desiccate a body; however, it's difficult to rely on statements of a perpetrator.
Desiccation of only the right leg likely corresponds with burial conditions (protruding from the grave).
Beaumont ${21}$ described a similar open-air case in a temperate climate with a partly decomposed and mummified body with a small degree of adipocere.

Meteorological conditions

Desiccation requires a dry environment, absence of humidity, and air current. ${1,4,18,23,24}$
Natural desiccation is not commonly documented except in domestic situations (e.g., concealed newborn deaths). ${18,23}$
Janaway et al. ${1,2,4}$ state desiccation wouldn't occur in buried bodies due to lack of airflow, contradicted by Aturaliya and Lukasewycz ${24}$ , who suggested desiccation is equally effective by soil interment as by air exposure.
Some sources state adipocere doesn't form in warm conditions. ${11}$
Recent literature indicates adipocere can form in warmer temperatures (22-40°C) with sufficient moisture and anaerobic conditions. ${4,12,25}$
Extremely hot conditions (over 40°C) hinder adipocere formation due to bacterial survival limitations.
Cold burial environments also limit adipocere formation. ${11,25}$
Anaerobic conditions favor adipocere, while aerobic conditions favor rapid decomposition. ${25–27}$
In summary, desiccation needs dry, aerated conditions, while adipocere needs anaerobic conditions, moderate temperature, and some moisture.
The exact burial date is unknown, making meteorological analysis difficult.
Weather data from a 25-day time frame in September and October were examined (nearest weather station at 1.5 and 12 km).
Temperature data were detailed in Fig. 3.
Coniferous woodland provides temperature buffering and protects against fluctuations.
There was no direct sun exposure of the grave.
It was a rather dry period for that time of year. The first 5–6 days had much precipitation, followed by 16 almost dry days.
The average relative humidity measured 84.6% (Fig. 4).
The average wind speed was between 4 and 22 km/h with a variable wind direction (Table 3).
An entire body can desiccate in days or weeks. Hardening of the skin may occur as early as the third day, but it is seen more frequently between the tenth day and 1 month. ${7–9,17,18,23}$
Adipocere visual identification ranges from 6 weeks to many years. ${6,28}$
Experimental observation indicated that adipocere can be formed a few hours after death. ${15}$
In this case, it is assumed that the victim was buried at the start of the dry period lasting 16 days.
Both desiccation and adipocere must have started rapidly post-mortem, limiting putrefaction.
Internal body water likely contributed to fat hydrolysis, dehydrating internal organs.
The body had largely not been disrupted by scavengers with only a couple of fingers and a small part of scalp tissue having been chewed, but with no damage to the victim’s leg on the surface, nor other parts of the body.
The minimal sign of maggot activity confirms this.
Low temperatures and precipitation during winter months likely delayed putrefaction and stabilised the body.
Adipocere and desiccation are not end products.
Even after 7 months, there was extensive adipocere and clear desiccation without putrefactive odor.
Localised dark blue and green discolouration around the back side of the upper torso and head due to seepage of body fluids. Galloway ${8,9}$ states that body fluids can be found in the immediate vicinity of desiccated remains.

Environmental Conditions

Desiccation is promoted in porous soils like sand due to capillarity and drainage. ${6,22,24}$
Adipocere formation accelerates in sand and silty sand due to well-draining properties. ${29,30}$
Conflicting viewpoints exist.
Dry or well-drained soil generally limits adipocere; clay soil with poor drainage is more likely to exhibit adipocere. ${11,31}$
Subtle differences in soil mineralogy and texture determine adipocere formation. ${28,32,33}$
Conflicting views on ideal soil pH for adipocere.
Forbes et al. ${25}$ stated that a highly acidic environment isn't conducive to adipocere, with a pH range of approximately 5–9 normally ideal.
Mant ${27}$ states that a highly acid pH reveals good adipocere formation.
In this case, burial occurred in coniferous wood of sandy soil with strong drainage and acid pH between 2.6 and 4.
This correlates with ideal conditions for desiccation.
The low pH limited bacterially induced putrefactive decay while helping to promote adipocere formation.

Burial Conditions

Clothing can affect desiccation rate. Aturaliya and Lukasewycz ${24}$ says desiccation rate is accelerated by clothing while Beaumont ${21}$ found that only body parts, not covered by clothing, were desiccated.
The nature of clothing fibers (natural vs. synthetic) matters due to moisture retention. ${34}$
Adipocere should form more easily when wrapped in clothing because it delays post-mortem changes and restricts insect activity. ${6,10,11,16,17,27}$
In this case, both adipocere and desiccation occurred despite the victim being naked.
Greater interment depth usually improves preservation. ${1,2,22,27}$
Shallow graves increase accessibility to insects and scavengers and expose bodies to temperature fluctuations. ${1,2,22,27}$
In this case, the shallowness of the grave appeared conducive for both adipocere and desiccation.
Uncompacted grave soil and brush concealment were present.
The protruding right leg desiccated due to greater airflow exposure.

Intrinsic factors due to the nature of the body itself

Personal characteristics (age, sex, body size) affect decomposition rates.
Thin individuals are more prone to desiccate (less fat), while adipocere forms easier on females (higher fat content). ${11,24,26}$
The deceased was a small, slim male (165 cm, 50.4 kg).
Rapid soft tissue drying prevents putrefaction by microorganisms and soil bacteria. ${5,7}$
Knight ${18}$ states that internal organ condition varies in desiccated bodies.
Jit et al. ${23}$ described desiccation with missing organs in a middle-aged man.
Sledzik and Micozzi ${7}$ state that internal organs are amongst the last structures to desiccate.
Spitz and Fisher ${35}$ mention poorer preserved or absence of organs in desiccated mummies recovered from temperate areas.
Aturaliya and Lukasewycz ${24}$ concluded that the supine position of a desiccated body leads to a poorer organ survival than a vertical position.
Adipocere inhibits bacterial growth, protecting organs in a dehydrated state. ${6}$
Adipocere can also occur on internal organs with high-fat levels. ${2}$
In this case, 65% of visceral organs were preserved (Visceral Index 65%).
This is a high percentage of survival for a 7-month shallow inhumation under temperate climate conditions
The foetal position may have protected the chest and abdominal cavity.
Good organ preservation was likely related to adipocere formation.
Preservation depends on the extent of putrefaction when adipocere formation begins. ${11}$

Conclusion

This case highlights the co-occurrence of desiccation and adipocere on a single body after 7 months of shallow burial.
This association is not uncommon, but it is very unusual in temperate climates like Belgium and not often described within the literature.
Desiccation may accompany adipocere in bodies where little or no exogenous water is available.
Given the time of year and environmental data, both processes likely began soon after burial.
After 7 months’ partial burial, there was extensive soft tissue present as well as preservation with limited signs of decomposition.
65% of the body’s internal organs were still surviving.
There were almost no signs of insect activity or scavenging.
Despite reports on adipocere and desiccation, few instances of both conditions represented in a single case have been recorded.
Subtle differences in environmental conditions, soil, burial, and individual factors were responsible for differential decomposition, with simultaneous adipocere and desiccation.