We investigated if metals, in particular known toxic and carcinogenic metals, were delivered by weapons producing amputations, body charring, burns, and were associated with WP burns, all injuries without fragments detectable in the body of the victims.
We show metal presence in fragment-free wounds, and a specific metal signature for each class of injury. We also show that metal was detected in a decreasing gradient of concentration from the "hit" side towards the other adjacent tissues.
We have been examining samples not easily available, which posed the issue of limited numbers. Our samples had been "unusually treated" with metals, both in terms of pressure, temperature and directionality of the spread, which may cause uneven distribution over the wound, and the biopsies had to be dissected further in smaller fragments for analysis; both these facts potentially increase the heterogeneity that can be expected among fragments, which we found.
Nonetheless we describe a consistent pattern of presence/absence of each metal in different wounds, a fact to which, for simplicity, we refer as the "metal signature" for each class of injury.
Thus, the presence of metals in unusually high amounts in biopsies from wounds without fragments is taken as proof of the fact that these metals were delivered by the weapon. The decreasing gradient of metal content from the wound site to more distal tissues agrees with the assumption of topic targeting by weapons carrying the metals. The regularity in the association of "specific metal signature" to a particular class of injury, supports unequivocally the validity of associating a class of injury to a kind of metal-delivering weapon.
The inclusion in the study of Gazeans with different kinds of injuries and the finding of different specific metal signatures, eliminates also any doubt of intrinsic differences in metal in the tissues of Gazeans versus controls, eventually due to environmental factors.
Most of the metals detected in many fold amounts in excess over the control in the biopsies of the victims have lethal and acute intoxicating effects (e.g. As, Ba, Al, Hg) and cause chronic pathologies in time (Al, Pb, Hg, Cd, As), including mental, reproductive, lung, skin and kidney diseases [14
In each class of injury were detected metals carcinogenic for humans (As, Cd, Hg, U, Cr (if CrVI), Ni (if oxide and sulfate)), or possible carcinogenic Co, V (if V2O5), Cu and Ni (if alloys)), or metals fetotoxic (i.e. genotoxic or/and teratogenic or/and impairing fetal development).
Some metals exert their effects in humans also via epidermal adsorption as Al and Hg, and others by os, as Mn, U, Cr (if VI) in human, and, in experimental animals, Cd, As, Co, Li, V, Mn, Zn and Cu.
In addition, U, Al, Ba, As, Cd, CrVI, Co, Cu, Pb, Hg, Ni, Sn and V behave as metalloestrogens, affecting sex hormones and glucocorticoid pathways, and interfering in sex determination, fertility and reproduction [16
]. Toxic and carcinogenic metals are capable to interfere at the molecular level also with oxidative stress pathways and with DNA duplication and repair [25
There is little information available on the effects of embodiment or assumption of many metals at once, as occurring in the victims here.
In addition, our analysis does not discriminate the isotopic form, the chemical associations or the physical status in which the metals are present, and, since their toxicity may vary with these, further investigation is necessary in these directions.
All these facts make difficult to provide conclusions on the effects that can be expected on the injuried, who assumed them during explosion of some kind and carry the metals embedded in their tissues. Nonetheless, the victims as well as whoever was in the vicinity, for a radium of unknown size, must also have been exposed to inhale and swallow the hot and high-pressurized metals dispersed by the blast. Also, around the target of weapons might have been produced a more or less large area of contamination of the ground by metals.
The final risks ensuing from the metal dispersion to people not directly hit possibly varies according to radium of spread, the absolute amounts and the specific characteristics (including metal form and aggregations) of each of the metals present in each of the weapon causing injuries without fragments.
Due to the many unknown factors illustrated above, it is possible only very adventitiously to calculate the pathogenic load of the amounts of metal in excess detected in the biopsies. Nonetheless, we compared the concentration of metals in the biopsies of victims with the minimal risk level (MRL) reported by ATSDR [27
], for the cases where this is available and applicable, and based on the assumption that the amount of metal embedded in wounds is the minimal absolute amount the victim might have assumed via inhalation. We calculated that the amounts assumed are, for all metals in all cases, higher than the MRL for acute exposures, and than the known cumulative MRL for chronic exposures. This has exception for only one of the determination for one sample for U, and for all the Cd levels. At this time, calculations are merely indicative and many facts still need to be investigated, as mentioned above.
Even the biopsies from WP burns contain, beside Al, a known component of the sectors that isolate the WP load of the ammunitions used in Gaza, also amounts of toxic metals, embedded deeply into the flesh of the burned. These are medium amounts of toxic and carcinogenic Cu, Sr, Ba, Co, Hg, U and Pb.
The main motivation to undertake this study was that the information sought could be utilized either to rule out metal implication in non fragmentation weapons or, if they were involved, to help designing remediation strategies for children and youths of reproductive age known to have been exposed directly or by proximity to the attacks, and/or presently living at ground level in the places where these attacks took place, where contamination may persist (our unpublished data) with consequent chronic assumption by people.
The potential of chelating compounds to alleviate the burden from retention of metals has been described, with its side effects [28
]. Melatonin has emerged as a promising remedy for metal intoxication [29
]: it protects against metal induced oxidative stress, is a natural oncostatic (in Al, Zn Pb intoxications) and is partial inhibitor of the genotoxicity by Cd, has anti estrogenic activity, and has no known side effects [30
]. Its limitation is that does not promote elimination of the metals from kidney, which can be achieved by chelating agents.
On the basis of our findings, we suggest that is an urgent priority to obtain information on the possibility of ongoing human contamination. Data on the metal amounts in the soil in this territory, collected before 2006, were published [32
] and could be taken as reference for eventual future soil contamination studies.