Accumulation of trace metals in the embryos and hatchlings of Chelonia mydas from Peninsular Malaysia incubated at different temperatures.

A variety of trace metals were measured in the egg contents of three clutches of Chelonia mydas collected from Kuala Terengganu state in Peninsular Malaysia. We quantified Mn, Cu, Zn, Se (essential trace metals) and As (anthropogenic pollutant) at several developmental stages obtained by incubating eggs at two different temperatures (27 °C and 31 °C). The incubation temperatures were chosen because they produce predominantly male or predominantly female hatchlings, respectively. The eggs were removed from the sand and washed before being placed in incubators, to ensure that the only possible source of the detected metals was maternal transfer. Other metals: Mo, Co, Ni, Cd, Sn, Sb, Hg, Tl and Pb (all non-essential metals) were detected at concentrations below the lower limit of quantitation (LLOQ). Trace metal concentrations, particularly [Zn], increased during development, other metals (Cu, As, Se and Cr) accumulated to a lesser degree than zinc but no significant differences were observed between the incubation temperatures at any stage of incubation. To date, only a few studies on trace metals in turtle embryos and hatchlings have been reported; this study will provide basic knowledge on the accumulation of trace metals during development at two different incubation temperatures.

Trace element concentrations in nesting flatback turtles (Natator depressus) from Curtis Island, Queensland, Australia.

The blood and eggs of the flatback turtle (Natator depressus) sampled when nesting at Curtis Island, Queensland, Australia. In the blood, zinc was present at the highest concentration of 151.15 ± 1.45 µg/L followed by copper (7.74 ± 0.09 µg/L). Lead was found only in some individuals. The measured trace elements in the blood were maternally transferred into the eggs. Other metals and metalloids detected in eggs were chromium, manganese, arsenic and selenium. Eggs showed a more complex trace element profile than blood, suggesting that they provided more representative tissues for determining maternal levels of trace element accumulation in N. depressus. Intra-clutch variation was over 15% for most of the studied trace elements suggesting one egg is not in sufficient to determine trace element accumulation within a clutch. Copper was the only element which was positively correlated with breeding age. Furthermore, no detectable levels of tin compound derivates were measured in N. depressus.

Silver deposits in cutaneous burn scar tissue is a common phenomenon following application of a silver dressing.

BACKGROUND: Silver dressings have been widely and successfully used to prevent cutaneous wounds, including burns, chronic ulcers, dermatitis and other cutaneous conditions, from infection. However, in a few cases, skin discolouration or argyria-like appearances have been reported. This study investigated the level of silver in scar tissue post-burn injury following application of Acticoat, a silver dressing. METHODS: A porcine deep dermal partial thickness burn model was used. Burn wounds were treated with this silver dressing until completion of re-epithelialization, and silver levels were measured in a total of 160 scars and normal tissues. RESULTS: The mean level of silver in scar tissue covered with silver dressings was 136 microg/g, while the silver level in normal skin was less than 0.747 microg/g. A number of wounds had a slate-grey appearance, and dissection of the scars revealed brown-black pigment mostly in the middle and deep dermis within the scar. The level of silver and the severity of the slate-grey discolouration were correlated with the length of time of the silver dressing application. CONCLUSIONS: These results show that silver deposition in cutaneous scar tissue is a common phenomenon, and higher levels of silver deposits and severe skin discolouration are correlated with an increase in the duration of this silver dressing application.

Silver absorption on burns after the application of Acticoat: data from pediatric patients and a porcine burn model.

Silver dressings have been widely used to successfully prevent burn wound infection and sepsis. However, a few case studies have reported the functional abnormality and failure of vital organs, possibly caused by silver deposits. The aim of this study was to investigate the serum silver level in the pediatric burn population and also in several internal organs in a porcine burn model after the application of Acticoat. A total of 125 blood samples were collected from 46 pediatric burn patients. Thirty-six patients with a mean of 13.4% TBSA burns had a mean peak serum silver level of 114 microg/L, whereas 10 patients with a mean of 1.85% TBSA burns had an undetectable level of silver (<5.4 microg/L). Overall, serum silver levels were closely related to burn sizes. However, the highest serum silver was 735 microg/L in a 15-month-old toddler with 10% TBSA burns and the second highest was 367 microg/L in a 3-year old with 28% TBSA burns. In a porcine model with 2% TBSA burns, the mean peak silver level was 38 microg/L at 2 to 3 weeks after application of Acticoat and was then significantly reduced to an almost undetectable level at 6 weeks. Of a total of four pigs, silver was detected in all four livers (1.413 microg/g) and all four hearts (0.342 microg/g), three of four kidneys (1.113 microg/g), and two of four brains (0.402 microg/g). This result demonstrated that although variable, the level of serum silver was positively associated with the size of burns, and significant amounts of silver were deposited in internal organs in pigs with only 2% TBSA burns, after application of Acticoat.

Comparison of the elemental composition of office document paper: evidence in a homicide case.

Fraudulent substitution of a page within a multiple page document such as a will or business contract, the counterfeit manufacture of paper banknotes, and linking ransom or extortion notes have all been the focus of criminal investigations at one time or another. In a recent homicide investigation, document examiners were requested to compare a threatening letter received by a business partner of the deceased with paper samples seized under warrant from a suspect's house. Through a quantitative elemental analysis of the concentrations of nine elements (Na, Mg, Al, Mn, Sr, Y, Ba, La, and Ce) within the questioned and specimen documents, determined by inductively coupled plasma-mass spectrometry (ICP-MS), it was concluded that (i) the paper of the threatening letter originated from a different source to that of the paper seized from the suspect's house and (ii) all six pages of paper seized from the suspect's house originated from the same source. This discrimination of paper is presented as both a statistical t-test analysis (99.9% confidence limit) as well as construction of an elemental fingerprint for individual replicates within the questioned and specimen sample populations. This is the first reported use of the comparison of the elemental composition of document paper, determined by ICP-MS, to assist in a criminal investigation.