Forensic Dna Identification From Human Remains Submerged In

Forensic DNA Identification from Human Remains Submerged in Water By Cheryl M. Lowe April 29, 2009

Background
There are many incidences where human remains end up in water
What are the distinguishing features of human remains found in water?
Is there a difference between salt water and fresh water in regard to DNA preservation?
http://www.adaweb.net/Portals/0/Coroner/images/07-0403-0544-17.jpg

Background
There are many factors that affect the integrity of DNA evidence from remains found in water
Limited research so far on how long DNA can be preserved in water

Definitions
Seawater = water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5%, or 35 parts per thousand
The density of surface seawater ranges from about 1020 to 1029 kg·m -3 , depending on the temperature and salinity
Fresh water = naturally occurring water on the surface such as bogs, ponds, lakes, rivers and streams and underground in aquifers and underground rivers
Low concentrations of dissolved salts
coastal areas freshwater may contain significant concentrations of salts derived from the sea if windy conditions have lifted drops of seawater into the clouds
http://i.treehugger.com/images/2007/10/24/fresh%20water-jj-001.jpg

Total Molal Composition of Seawater (Salinity = 35)
Component Concentration (mol/kg)
H 2 O 53.6
Cl - 0.546
Na + 0.469
Mg 2+ 0.0528
SO 4 2- 0.0282
Ca 2+ 0.0103
K + 0.0102
C T 0.00206
Br - 0.000844
B T 0.000416
Sr 2+ 0.000091
F - 0.000068
Source: http://en.wikipedia.org/wiki/Seawater

Remains Submerged in Water
Favorable conditions for adipocere
Increased saponification due to exposure to excess of water
Cells absorb water until rupture, then release fatty contents that are then hydrolyzed and hydrogenated
Adipocere is common in remains found in bathtubs, ponds, lakes, oceans
Bloating, skin slippage, wrinkling of hands and feet common
O’Brien, et al.

Remains Submerged in Water
Tissue loss from:
Effects of the water current
Chemical composition of water
Industrial waste water
Predation by insects, marine animals, fish
O’Brien, et al.

Body at 4 weeks O’Brien, et al.

Stages of adipocere formation on a body floating in water for 3 months Stage I – 4 Float, bloat, ovapositioning and hatching Stage II 4–6 Early: insect activity, skin sloughing, cutis anserina, residue formation on water surface Stage III 6–8 Early: adipocere formation, microbial growth, color loss; Increased: insect activity, skin sloughing, cutis anserina, residue formation on water surface Stage IV 8–10 Increased: adipocere formation, microbial growth; Advanced: insect activity, cutis anserina, color loss, residue formation on water surface Stage V 10–12 Advanced: adipocere formation, microbial growth; Reduced: insect activity O’Brien, et al.

Case Example – Fresh Water
Decomposed remains found in a dam on the Seine River after 3 years
Successful recovery of DNA profiles using Profiler Plus kit from bone (10 STR loci and amelogenin)
No results from saponified sternocleidomastoid muscle

Case Example – Fresh Water

Case Example – Salt Water
Skeletonized remains found in 2 rubber boots in March 2005, 145m deep in the Southern Australian coast (Great Australian Bight)
DNA analyses on reference samples from relatives of fishermen who had disappeared in the area
Victim identified with Profiler Plus kit as a 52 year old prawn fisherman, swept off of boat about 10 years earlier

DNA stability maintained by low light conditions, cold temperatures, alkaline pH of the ocean floor (pH was between 7.5 and 8.5)
Byard, et al.

Remains found relatively preserved within rubber boots
Wedges of bone from distal ends of each tibia were submitted for DNA analysis
Homicide with dismemberment was considered as a possible scenario
Possibility of drifting of remains along the ocean floor…could have come from coastal areas

DNA Profiles Obtained Byard, et al.

DNA Stability in Water
DNA integrity can be preserved under the following conditions:
High mineral content of water: high amounts of calcium, magnesium, carbonates, sulfides, sulfates
Anaerobic environment: limits oxidative damage of DNA, as well as bacterial and fungal growth
Neutral pH: around 6.1 to 6.9, buffered from presence of carbonates
Low oxygen tension

DNA Stability in Water
From 1984 to 1987, there were 177 ancient individuals of all ages recovered from Windover pond, Florida Atlantic Coastal Ridge
Intact crania with pieces of preserved brain matter
Pond possessed favorable conditions for DNA preservation; preliminary Southern blot showed traces of human DNA

Discussion
Water can preserve DNA evidence in most cases
The most important factor in the recovery of DNA evidence from submerged remains seems to be time
However, it can sometimes complicate data…especially in mass disaster investigations (Southeast Asian tsunami)

Conclusions
DNA identification by itself is not fully reliable from human remains found in aqueous environments
Important for other metadata to be incorporated, such as dental identification, anthropological studies
Further research needs to be done

Bibliography
Crainic K, Paraire F, Leterreux M, Durigon M, Mazancourt P. Skeletal remains presumed submerged in water for three years identified using PCR-STR analysis. J Forensic Sci, Sept. 2002, Vol. 47, No. 5. (1-3)
Byard RW, Both K, Simpson E. The identification of submerged skeletonized remains. American Journal of Forensic Medicine and Pathology. March 2008, Vol. 29, No. 1, pages 69-71.
O’Brien TG, Kuehner AC. Waxing grave about adipocere: soft tissue change in aquatic context. J Forensic Sci, March 2007, Vol. 52, No. 2, 294-301.
Herrmann Bernd, Susanne Hummel. Ancient DNA: Recovery and Analysis of Genetic Material from Paleontological, Archaeological, Museum, Medical, and Forensic Specimens . Springer, 1994. Pages 105-106.
Graw M, Weisser HJ, Lutz S. DNA typing of human remains found in damp environments. Forensic Science International 113 (2000) 91-95.
Pacher J, Cameron J. Submersion cases: a retrospective study 1988-1990, Med. Sci. Law 32 (1992) 15-17.
Swann H, Spafford N. Body salt and water changes during fresh and sea water drowning, Texas Rep. Biol. Med. 9 (1951) 350-384.

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