Decomposition of partially submerged remains: a study on the reliability of insect colonisation for PMI/PMSI estimation.

The terrestrial decomposition of remains and associated insect colonisation have been highly researched, and recently studies have expanded to investigate the aquatic decomposition of remains. However, there are instances where remains may experience both terrestrial and aquatic conditions simultaneously due to partial submersion in tidal areas, or influx or efflux of water caused by flood or drought. Decomposition and post-mortem interval (PMI) research to date has focused on remains wholly exposed to either terrestrial or aquatic environments, with limited consideration of dual simultaneous exposure. This study was conducted in artificial lentic environments to ascertain how simultaneous zones of terrestrial and aquatic environments on a single body may impact decomposition. Three trials were completed over a period of 12 months, with each trial consisting of 12 stillborn piglets; three partially submerged head exposed, three partially submerged abdomen exposed, three fully submerged aquatic controls and three terrestrial controls. Decomposition stage and rate were inferred from physical characteristics and insect activity. The decomposition rate of the exposed region of each piglet was significantly faster than the submerged region. The exposed zone of each was colonised by insects and reached skeletonization, whereas the submerged zone without orifice exposure had no insect activity and had a significantly slower decomposition rate. This indicated the ability to utilise terrestrial entomological approaches to estimate a minimum PMI for the exposed portion of the remains. However, without the ability to determine the amount of time the remains may have been submerged for, this estimation represents only a minimum PMSI, with the possibility the remains were submerged for a period of time without insect access and colonisation.

Fibre persistence on submerged substrates: The effect of flow rate over extended submersion periods.

Through both casework and research, fibres have been found to have the particularly useful ability to persist and remain exploitable after submersion. However, direct analysis of the persistence ability remains in early stages, and in particular, submersion times above a day have not been thoroughly studied. This study aims to both extend understanding of the impact of flow rate and submersion periods of up to 28 days. A blended polyester/cotton green fabric was abraded to increase transfer and then dragged over a black cotton substrate. Six replicates of these substrates were then submerged in artificial flow cells at various flow rates for 28 days. These were illuminated under UV light and photographed prior to submersion, at set times during submersion and after submersion. Another set of six replicates were imaged, submerged into a river and then recovered and re-imaged after 28 days. The population of fibres was then counted using these photographs, and a mix of one-way and two-way ANOVA tests were applied, in combination with Tukey's HSD, to detect significant differences across time and flow rate categories. Loss predominantly occurred on within the first 24 hours, in agreement with previous work. However, distinct from previous work there was a slow, approximately logarithmic loss over the balance of the submersion period. While significant differences were found between flow categories, there was no clear relationship between flow rate and persistence. The behaviour of the river samples was well-predicted by laboratory samples. 100 % fibre loss was never observed, with the maximum instead being 95.45 %. These results extend the understanding of fibre persistence on submerged substrates beyond the short submersion times in previous literature, and provide some deeper understanding of the impact of flow rate.

Drowning.

Drowning is responsible for considerable morbidity and mortality worldwide, and it is estimated that 90% of drownings are preventable. Drowning is defined as "the process of experiencing respiratory impairment from submersion/immersion in liquid." Emergency providers should focus on airway management and rapid delivery of oxygen to interrupt the drowning process and improve patient outcomes. Patients with minimal or no symptoms do not require any specific diagnostic workup, aside from physical examination and 4 to 6 hours of observation prior to discharge. Patients with more severe symptoms may present with rales and foamy secretions, and should be managed with high-concentration oxygen and positive airway pressure.

Inhibition of acid rock drainage with iron-silicate or phosphate film: in rainy and submerged environments.

Iron phosphate-based coating and iron silicate-based coating were used to inhibit the oxidation of sulfide minerals in rainy and submerged environments. The inhibiting effectiveness of coating agents on the oxidation of iron sulfide minerals was investigated using pyrite and rock samples resulting from acid drainage. The film formed with both surface-coating agents was identified by pyrite surface analysis. It was also confirmed that the formation of coatings varies depending on the crystallographic orientation. The inhibitory effects under rainy and submerged conditions were investigated using column experiments. Submerged conditions accelerated deterioration compared to that under rainy conditions. Iron phosphate coating had a significantly better oxidation-inhibitory effect (84.86-98.70%) than iron silicate coating (56.80-92.36%), and at a concentration of 300 mM, H+ elution was inhibited by more than 90% throughout the experiment. Furthermore, methods for effective film formation were investigated in terms of producing Fe3+; (1) application of coating agents mixed with oxidant (H2O2), (2) application of coating agent after the use of the oxidant. In a rainy environment, applying iron phosphate-based coating using the sequential method showed oxidation inhibition effects for cycles 1-9, whereas applying the mixed material showed effects for cycles 9-13. The use of a surface-coating agent after applying an oxidant did not inhibit oxidation. The surface coating agent and the oxidizing agent should be applied as a mixture to form a film.

Aquatic conditions & bacterial communities as drivers of the decomposition of submerged remains.

Aquatic decomposition, as a forensic discipline, has been largely under-investigated as a consequence of the highly complex and influential variability of the water environment. The limitation to the adaptability of scenario specific results justifies the necessity for experimental research to increase our understanding of the aquatic environment and the development of post-mortem submersion interval (PMSI) methods of estimation. This preliminary research aims to address this contextual gap by assessing the variation in the bacterial composition of aquatic biofilms as explained by water parameter measurements over time, associated with clothed and bare decomposing remains. As part of three field investigations, a total of 9 still-born piglets (n = 3, per trial) were used as human analogues and were submerged bare or clothed in either natural cotton or synthetic nylon. Changes in the bacterial community composition of the water surrounding the submerged remains were assessed at 4 discrete time points post submersion (7, 14, 21 and 28 days) by 16 S rRNA gene Next Generation Sequencing analysis and compared to coinciding water parameter measurements (i.e. conductivity, total dissolved solids (TDS), salinity, pH, and dissolved oxygen (DO)). Bacterial diversity was found to change over time and relative to clothing type, where significant variation was observed between synthetic nylon samples and bare/cotton samples. Seasonality was a major driver of bacterial diversity, where substantial variation was found between samples collected in early winter to those collected in mid - late winter. Water parameter measures of pH, salinity and DO were identified to best explain the global bacterial community composition and their corresponding dynamic trajectory patterns overtime. Further investigation into bacterial community dynamics in accordance with varying environmental conditions could potentially lead to the determination of influential extrinsic factors that may drive bacterial activity in aquatic decomposition. Together with the identification of potential bacterial markers that complement the different stages of decomposition, this may provide a future approach to PMSI estimations.

A fundamental study on postmortem submersion interval estimation by metabolomics analyzing of gastrocnemius muscle from submersed rat models in freshwater.

In forensic practice, determining the postmortem submersion interval (PMSI) and cause-of-death of cadavers in aquatic ecosystems has always been challenging task. Traditional approaches are not yet able to address these issues effectively and adequately. Our previous study proposed novel models to predict the PMSI and cause-of-death based on metabolites of blood from rats immersed in freshwater. However, with the advance of putrefaction, it is hardly to obtain blood samples beyond 3 days postmortem. To further assess the feasibility of PMSI estimation and drowning diagnosis in the later postmortem phase, gastrocnemius, the more degradation-resistant tissue, was collected from drowned rats and postmortem submersion model in freshwater immediately after death, and at 1 day, 3 days, 5 days, 7 days, and 10 days postmortem respectively. Then the samples were analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate the dynamic changes of the metabolites. A total of 924 metabolites were identified. Similar chronological changes of gastrocnemius metabolites were observed in the drowning and postmortem submersion groups. The difference in metabolic profiles between drowning and postmortem submersion groups was only evident in the initial 1 day postmortem, which was faded as the PMSI extension. Nineteen metabolites representing temporally-dynamic patterns were selected as biomarkers for PMSI estimation. A regression model was built based on these biomarkers with random forest algorithm, which yielded a mean absolute error (± SE) of 5.856 (± 1.296) h on validation samples from an independent experiment. These findings added to our knowledge of chronological changes in muscle metabolites from submerged vertebrate remains during decomposition, which provided a new perspective for PMSI estimation.

Oxidative stress and NF-KB/iNOS inflammatory pathway as innovative biomarkers for diagnosis of drowning and differentiating it from postmortem submersion in both fresh and saltwater in rats.

BACKGROUND: Finding a dead body in water raises an issue concerning determining the cause of death as drowning because of the complex pathophysiology of drowning. In addition, the corpse may be submersed postmortem. OBJECTIVE: Evaluate the role of oxidative stress markers and NF-KB/iNOS inflammatory pathway as diagnostic biomarkers in drowning and whether they could differentiate freshwater from saltwater drowning. METHODS: This study included forty-five adult male albino rats classified into five groups: control group (C), Freshwater-drowned group (FD), Freshwater postmortem submersion group (FPS), saltwater-drowned group (SD), and saltwater postmortem submersion group (SPS). After the autopsy, the rats' lungs in each group were prepared for histological, immunohistochemical (caspase 3, TNF-α, NF-kB, COX-2 & iNOS), biochemical studies; MDA, NOx, SOD, GSH, VCAM-1, COX-2; and RT-PCR for the relative quantification of NF-kB and iNOS genes expression. RESULTS: Lung oxidative markers were significantly affected in drowned groups than in postmortem submersion groups. Inflammatory pathway markers were also significantly increased in the drowned groups, with concern that all markers were significantly affected more in saltwater than in freshwater drowned group. CONCLUSIONS: It is concluded that the tested markers can be used accurately in diagnosing drowning and differentiating it from postmortem submersion with a better understanding of the mechanism of death in drowning as both mechanisms, inflammatory and oxidative stress, were revealed and involved.

Drowning and Nonfatal Drowning in Children and Adolescents: A Subsequent Retrospective Data Analysis.

Fatal and nonfatal drowning are among the leading causes of death and lifelong severe neurological impairment among children and adolescents. This study aimed to complement research from Leipzig 1994-2008 to seek trends within risk factors, treatments, and outcomes throughout the last decade. We retrospectively investigated data of 47 inpatients aged 0-18 admitted to Leipzig University Department of Pediatrics who matched ICD-10 code T75.1 from 2008 to 2020 and compared them to a preceding study at the same institution. We also examined the prognostic value of parameters regarding the patients' outcomes. There were three median incidents per annum. The median age was 2.75 years; 76% of incidents happened in males. An accumulation was seen during the summer months and weekends. Most drowning incidents occurred in private ponds or pools (48.9%). Thirty-nine children were discharged without resulting morbidity, four showed neurological impairment, and three died. Risk factors concerning age, sex, and incident characteristics were confirmed. Special supervision needs still apply to 1-3-year-old male children or children with pre-existing health conditions around private pools and ponds. Hospitalization duration shortened, and morbidity and lethality decreased since the previous study. There was structural improvement in primary care and medical documentation. Parameters suggesting good outcomes include a submersion time < 5 min, GCS > 3 points, spontaneous movement upon admission, remaining pupillary light response, the absence of cardiovascular arrest, body temperature ≥ 32 °C, pH > 7, blood glucose < 15 mmol/L, lactate < 14 mmol/L, base excess ≥ -15 mmol/L, and the absence of ARDS. Clear legislation can contribute to improved private home water safety. Further studies should include a broad in- and outpatient spectrum and standardized incident documentation presupposing Utstein-style reporting. Regular reinvestigation of consistent geographical regions facilitates process evaluations of drowning epidemiology and therapy evolution.

Evaluation of Storage Conditions and the Effect on DNA from Forensic Evidence Objects Retrieved from Lake Water.

DNA analysis of traces from commonly found objects like knives, smartphones, tapes and garbage bags related to crime in aquatic environments is challenging for forensic DNA laboratories. The amount of recovered DNA may be affected by the water environment, time in the water, method for recovery, transport and storage routines of the objects before the objects arrive in the laboratory. The present study evaluated the effect of four storage conditions on the DNA retrieved from bloodstains, touch DNA, fingerprints and hairs, initially deposited on knives, smartphones, packing tapes, duct tapes and garbage bags, and submerged in lake water for three time periods. After retrieval, the objects were stored either through air-drying at room temperature, freezing at -30 °C, in nitrogen gas or in lake water. The results showed that the submersion time strongly influenced the amount and degradation of DNA, especially after the longest submersion time (21 days). A significant variation was observed in success for STR profiling, while mtDNA profiling was less affected by the submersion time interval and storage conditions. This study illustrates that retrieval from water as soon as possible and immediate storage through air-drying or freezing before DNA analysis is beneficial for the outcome of DNA profiling in crime scene investigations.

The Influence of a Single Infrapositioned Anterior Ankylosed Tooth or Implant Supported Restoration In Smile Attractiveness.

OBJECTIVES: To investigate the influence of a single infrapositioned ankylosed tooth or implant supported restoration, in smile attractiveness. MATERIAL AND METHODS: A series of 48 digital modified images, simulating a varying degree of infraposition(from 0.25 to 2.0 mm, with a step of 0.25 mm), was created for each one of the maxillary anterior tooth, by altering the full-portrait image of a smiling male adult, in medium and high smile lines. For the model with the high smile line, also a series of 24 digital modified images simulating infraposition of a single anterior tooth with a restored incisal edge was created. Smile attractiveness for each one of the images was evaluated from 160 participants (80 dentists and 80 laypersons), implementing a visual analog scale. RESULTS: For the images with the high smile line, an infraposition ≥ 0.25mm in central incisor's region and ≥ 0.5mm in the region of the lateral incisor or the canine, had a negative effect on the perceived smile attractiveness both for the dentists and the laypersons. Regarding the medium smile line, an infraposition ≥ 0.5mm in central and lateral incisor's region, had a negative effect on the perceived smile attractiveness for both groups of observers. In the area of the canine, infraposition ≥ 0.5mm for the dentists and ≥ 0.75mm for the laypersons, had a negative impact on the smile attractiveness. CONCLUSIONS: Even a minor infraposition of a single maxillary anterior ankylosed tooth or implant supported restoration, can reduce the perceived attractiveness of the face. Infraposition in canine's area can be better tolerated in a medium, compared to a high smile line. In patients with a high smile line prosthetic intervention in order to restore the incisal edge of an infrapositioned tooth, without to harmonize the gingival contour, can be beneficial for the lateral incisor, ineffective for the central incisor and unfavorable for the canine.

Wilderness Medical Society Clinical Practice Guidelines for the Treatment and Prevention of Drowning: 2024 Update.

The Wilderness Medical Society convened a panel to review available evidence supporting practices for acute management of drowning in out-of-hospital and emergency care settings. Literature about definitions and terminology, epidemiology, rescue, resuscitation, acute clinical management, disposition, and drowning prevention was reviewed. The panel graded available evidence supporting practices according to the American College of Chest Physicians criteria and then made recommendations based on that evidence. Recommendations were based on the panel's collective clinical experience and judgment when published evidence was lacking. This is the second update to the original practice guidelines published in 2016 and updated in 2019.

Submersion Injuries and the Cost of Injury Associated with Drowning Events in the United States, 2006-2015.

INTRODUCTION: The World Health Organization has reported submersion injuries as the third most common cause of death due to unintentional injury in the world. Greater detail in the rates, risk factors, and healthcare associated costs of submersion injuries could be instrumental in demonstrating the need for further funding and intervention. METHODS: The study was a cross-sectional analysis of a nationally representative dataset of inpatient and emergency department (ED) encounters between 2006 and 2015 in the United States (US). Healthcare utilization costs were provided within the datasets and adjusted to reflect actual charges and provider fees. Lastly, the final cost values were adjusted to the 2020 US dollar (USD) and summarized using a log adjusted mean. RESULTS: On average, there were 11,873 submersion injuries per year that presented to the ED in the US. Resulting in a rate where approximately 9 out of every 100,000 ED visits were associated with a submersion injury. Slightly more than 6% died in the ED, 24.2% were admitted, and 69.3% were discharged from the ED. In total, annual cost of submersion injuries in the US for ED care is approximately $12.5 million, inpatient care is approximately $27.5 million, and total annual healthcare cost exceeds $40 million. DISCUSSION: While these results only represent a fraction of the total cost associated with submersion injuries, it remains substantial and unchanged over the 10-year study period. Certain demographic groups showed higher rates of injury and disease burden, thus bearing a greater amount of the cost.

Caregiver water safety knowledge and views of toddler water competency.

BACKGROUND: Drowning is the leading cause of death for toddlers. When caregivers are knowledgeable about water safety, they can provide the best protection against drowning. The aim of this study is to survey caregivers of toddlers to better understand factors associated with water safety knowledge, attitudes about pool supervision, and toddler water competency skills. METHODS: An online survey of 650 parents/caregivers of 1-4-year-old toddlers asked about the caregiver's water safety and swimming background and views on pool supervision. Surveys included a true/false section of ten basic water safety knowledge questions. Caregivers also reported on toddler swim lesson history and whether their toddler could perform six standard water competency skills. Linear regression identified factors predictive of water safety knowledge. RESULTS: On average, caregivers selected the correct answer on six out of ten water safety knowledge questions. Water safety knowledge was predicted by the relationship of the caregiver to the toddler, gender, race, education, prior CPR training, caregiver swim capability, and reported pool supervision style. On average, caregivers reported that their toddler could perform half of the water competency skills. The majority of the toddlers had taken swimming lessons. One third of caregivers believed that after a toddler has had swimming lessons, they don't need to be watched as closely when they are in a pool. CONCLUSIONS: Findings suggest that water safety knowledge is poor and that there are misconceptions about toddler supervision needs. Efforts are needed to improve water safety knowledge and to change perceptions about supervision among caregivers of toddlers.

Drowning is fast, silent, and preventable: a Texas example of research in action.

Drowning is a major public health issue internationally. In August 2022, a report was released by members of the Central Texas Drowning Prevention Action Team that provided data on drowning fatalities in Texas between 2006 and 2020 and offered recommendations for drowning prevention actions. The information in the Texas drowning report is an important contribution to the field of injury prevention. The aim of this editorial is to allow the information in the report to be available to a wider audience and potentially used as a model for other states.

Traumatic Injuries and Radiographic Study Utilization Among Children With Drowning Presenting to U.S. Pediatric Hospitals.

OBJECTIVE: The role of traumatic injuries in fatal and nonfatal drownings is poorly described. We sought to characterize the incidence of traumatic injuries and diagnostic imaging performed among children who received pediatric hospital care for drowning. METHODS: We conducted a retrospective study of children (≤18 years) with drowning encounters at 45 pediatric hospitals, October 2015 through December 2020. We described the presence of clinically important traumatic injuries to the following body regions: brain, spinal cord, thoracic and intra-abdominal organs, axial skeleton, pelvis, and long bones, and major vessels. We described patient characteristics and radiographic testing. We compared patients with and without traumatic injuries using the Fisher's exact and Wilcoxon signed rank tests. RESULTS: We identified 10,397 children with a drowning encounter. Most (83.4%) were treated in the emergency department and 52.8% were admitted. There were 238 (2.3%) encounters with clinically important traumatic injuries. Intracranial injury was the most common (1.0%) with other traumatic injuries occurring in ≤0.5%. Less than 2% of children had a moderate or severe injury severity score and approximately half of these children had a clinically important traumatic injury. Among children with traumatic injuries, a higher proportion were 10 to 14 or 15 to 18 years old and from ZIP codes with lower median household income. Computerized tomography imaging was performed in the following proportions: brain (11.4%), cervical spine (3.7%), abdomen/pelvis (1.2%), chest (0.5%) and face/orbits (0.2%). CONCLUSIONS: Clinically important traumatic injuries in children with drowning are rare. Further studies are needed to guide the optimal utilization of radiographic studies in this population.

Measured Submersion Times in Underwater Hockey Are Inconsistent With Its Classification as an Extreme Apneic Sport.

Underwater hockey (UWH) is a sport played at the bottom of a pool without the use of breathing devices such as scuba equipment. It has been classified as an extreme apneic sport based on perceptions of prolonged underwater submersion times during play. This study measured 2000 submersion times during UWH games and compared the average measured submersion times to estimates by UWH players and aquatics directors. The average measured submersion time was 11.0 seconds (SD:3.7) with a range of 4 to 27 seconds, but aquatics directors' estimates were over 100 percent longer (22.7 seconds). While observed active drop times typically lasted for 12.1 seconds (SD: 3.7), observed drop times with no puck lasted on average 9.3 seconds (SD:3.0). When compared to director and player estimates, actual/observed drop times were significantly (p<0.05) lower for overall drop times, active drop times, and drop times without a puck. The average submersion times measured in this study more closely resembled competitive swimming, a breathing-controlled sport, and contradicted lay press reports of routine submersion for one to three minutes, which implies a risk for a hypoxic blackout. The results of this study may mitigate safety concerns about UWH as a high-risk sport for a hypoxic blackout.

Long-term trends of salinity in coastal wetlands: Effects of climate, extreme weather events, and sea water level.

Coastal freshwater ecosystems play major roles as reservoirs of biodiversity and provide many ecosystem services and protection from extreme weather events. While they are of particular importance worldwide, they are affected by a large variety of anthropogenic threats, among which salinization has been less studied, particularly regarding large temporal and spatial data sets based on real case scenarios, while salinity can impact biodiversity and ecosystem functioning. In this study, we investigated the variations of salinity across long-term (1996-2020) and seasonal (monthly records) temporal scales and spatial (varying distance to the coastline) scales in water bodies of two typical temperate coastal wetlands situated on the Atlantic coast of France. We complemented our analyses with models of sea water levels computed at both sites across 2000-2020. Our detailed data set allowed for highlighting that salinity in ponds varied seasonally (higher during summer, due to decreased precipitation and higher temperature), but also spatially (higher closer to the seashore, which pattern increased through time). Over the long term, decreased precipitation but not increased temperature induced increasing salinity. We also highlighted contrasted long-term patterns of salinity changes on these two coastal wetlands, with one site were salinity decreased over time linked to the responses to marine flood, allowing to document the temporal dynamics of salinity following a massive intrusion of sea water. Complementarily, at both sites, water levels at high tides increased through time, a pattern which can induce additional salinization. To our knowledge, our study is the first to investigate long-term changes in salinity in coastal wetlands through natural processes (e.g. seaspray, seasonal variations) and ongoing climate perturbations (e.g. marine surges linked to extreme weather events, increased temperature and decreased precipitations).

Greater flowering and response to flooding in Lythrum virgatum than L. salicaria (purple loosestrife).

Newly introduced trait diversity can spur rapid evolution and facilitate local adaptation in the introduced plant Lythrum salicaria. The horticultural plant L. virgatum might further introduce meaningful trait variation by escaping into established L. salicaria populations or by hybridizing with L. salicaria. Although many experiments have focused on L. salicaria genotypes, relatively little is known about L. virgatum ecology. We used a greenhouse common garden to compare traits and flood response of L. salicaria and L. virgatum collected from two sources each in their native range. We tested the hypotheses that these two wetland taxa have comparable responses to flooding (inundation), and that flood tolerance correlated to higher fitness. Flooding produced stronger stress responses in L. virgatum. Compared to L. salicaria, L. virgatum shifted more aboveground allocation away from reproduction, decreased inflorescence biomass by 40% more, and produced 7% more stem aerenchymatous phellum, a specialized tissue that maintains aeration. Despite these more pronounced responses to flooding stress, L. virgatum had higher fitness (inflorescence biomass and reproductive allocation) than L. salicaria. Overall, L. virgatum differed from L. salicaria in functionally important ways. Lythrum virgatum persisted under flooding and produced more reproductive biomass than L. salicaria under both flooded and non-flooded conditions. However, inundation stressed L. virgatum more than L. salicaria. Lythrum virgatum is likely able to establish into the wetland habitats in which L. salicaria prevails but may possess broader habitat tolerances.

Applicable Forensic Biomarker for Drowning Diagnosis: Extracellular Signal-Regulated Kinase 2 (ERK2).

Drowning is a common cause of accidental death worldwide, and it continues to be a serious public health problem. However, diagnosing drowning is a challenging task in forensic investigation because it is difficult to prove actual drowning and other submerged deaths with the autopsy techniques that are currently in use. Here, we show biomarkers that may be helpful for the diagnosis of drowning. We divided the experimental animals into four groups (drowning, postmortem submersion, hypoxia, and control) to evaluate the expression patterns of extracellular signal-regulated kinase 1/2 (ERK1/2). On gene expression analysis, only ERK2 was found to be significantly increased in the drowning groups compared to the other cases. In the immunoblot analysis, phosphorylated ERK2 (p-ERK2) was found to be upregulated in the drowning groups. Immunohistochemical staining also showed that p-ERK in alveolar cells revealed a granular pattern in the drowning groups. However, the expression pattern of ERK2 over time after drowning differed between the freshwater and seawater drowning groups. Taken together, these results indicate that ERK2 may be useful for distinguishing between drowning and postmortem submersion if the postmortem interval (PMI) of drowning is short. Conversely, if the PMI is long from the time that death occurs until the discovery of dead bodies, it is possibly more helpful for identifying between freshwater and seawater drowning.

Assessment of post-mortem submersion interval using total aquatic decomposition scores of drowned human cadavers.

Investigating drowning-related deaths remains a significant problem for forensic personnel all over the world. The previously published decomposition scoring method like the total aquatic decomposition (TAD) score promises to estimate the correct post-mortem submersion interval (PMSI) in aquatic habitats through the assessment and calculation of the decomposition rate and accumulated degree days (ADD). The current study comprised of 53 drowned death cases belonging to various districts of Haryana from May 2016 to August 2017. The regression and Pearson's correlation indicated a significant correlation between the TAD scores and the actual ADD (calculated through water temperatures) (r2  = 0.917) and between the actual and the estimated ADDs (calculated through TAD scores used by Heaton et al. [21]) (r = 0.9585). The results indicated that the estimated ADD tends to over predict the PMSI compared to the actual ADD. It is further confirmed by paired t-test, which showed the mean of actual ADD (mean = 349) to be significantly lower than the mean of estimated ADD (mean = 663). Moreover, these methods will help forensic investigators and researchers formulate region-specific regression equations for PMSI estimation.