**4.9 Arsenic can mar litigation caused by lead bullet**

Since lead decreases arsenic bioavailability [145], it can reduce the chance of arsenic poisoning and vice versa. Hence there is need for knowledge of toxicokinetic changes of lead for better evaluation and interpretation of preclinical safety and clinical hazard [146]. Also the dose of bullets can be used to deduce lead concentration in the body, and the area under curve (AUC) base line should be compared with lead AUC response to eliminate uncertainty and variability [147]. This may be highly beneficial in biopsy [148] and autopsy of living or dead person tissues, affected by lead bullets. Under this condition, statistical moment theory instead of the compartmental model may be used to calculate mean residence time [149]. Elimination and absorption rate constants and volume of distribution may vary with age, gender, weight, clinical status, genetic variability and co-administration of lead with another drug or toxicant. Hence therapeutic monitoring of plumbism is very important [150]. Therefore, Pharmacokinetic/Pharmacodynamic (PK/PD) relationship is very important guide for identifying susceptibility and treatment potential of poisoning from lead bullets [151]. Lead distribution and clearance were 2.5 and 4 times higher in lactating and non-lactating animals respectively [152], and 10 μg/dl limit issued by Centre for Disease Control (CDC) is relatively high [89]. Relationship between blood lead concentration and lead intake is non-linear, [153], but at low concentration the kinetic is linear and at 60 μg/dl in erythrocytes which corresponds to blood level of 25 μg/dl, the kinetic becomes non-linear [153], indicating that lead kinetics is Michaelis–Menten. Accessibility pool parameters (Vd, Clb, β, MRT) can be used compartmentally and non-compartmentally [154]. Gunshot residue and shooting distance could be used to determine contact and near contact wound in putrefied or charred bodies [155, 156]. In conventional rifles and gun bullet projection, the projectile requires high altitude and glides with subsonic speed and a good ratio lift/drag. This is applicable with bullets having projectiles of 2–5 times [157]. Threshold level (25 μg/m<sup>3</sup> ) in air is dangerous to health [158]. Velocity of 150–170 fps is required by bullet to penetrate skin [121]. But bones change the speed of bullets greatly, by changing their course and slowing them down [159]. Origin of bullet can be determined using the major/minor axis which determines the impact angle, although modern laser methods provide better results. Semi-automatic gun and bullet system (7.62 mm) is more effective [160]. Toxicosis from lead ammunition in predatory and scavenging birds have been reported in Argentina, Chile, Swiss Alps, Namibia, South Africa, Botswana, Israel, French Pyrenees, Spain, Iberian Peninsula, Sweden, USA, Granada, UK, Japan, Poland, Finland, Ireland, Portugal, Italy and Canada [17]. International suspension limit of blood lead is 10–70 μg/dl in females and 20–70 μg/dl in males, respectively. However, 5–80 μg/dl and above can cause hypertension, kidney dysfunction, neurocognitive deficits, colic, gout, sperm abnormalities, anaemia, peripheral neuropathy and encephalopathy (**Table** 3). Hence, there is narrow margin of safety between blood lead suspension and subclinical effects [161]. Therefore, the

1899 Hague Declaration is about abstinence from the use of bullets; an effective treaty applied for over 100 years, but may likely face modern challenges [162]. At short range of shooting bullets, the amount of energy absorbed is increased which is proportional to striking velocity [163]. Jauhari experimented on bullet crochet, defined as deflection of a bullet from its course by firing low velocity handgun cartridges on targets [164].

#### **4.10 The importance of ban on the use of lead ammunition**

Gun at 0.436o hit the centre of a target 1 m off the ground and 1 km away with an air temperature of 27.2° C. Hence hollow bullet has more drag and hit the centre of the target at a different angle [165]. Bullets from high velocity modern rifles produce lead fragments, and lead shot (6.1 μg/g) could kill birds, when the meats from such birds were consumed, blood concentration (15–128 mg/l) was detected in the blood of human consumers, as well as 24–50 and 9–180 μg/l were detected in mothers and newborns, respectively [166]. Low blood lead concentration (LBLC) is associated with decreased intelligent quotient (IQ) in children [167]. Hence the use of lead ammunition has been banned in the USA, Canada, Mexico, Oceania, Austria, Japan, South Africa, Bennin, Guinea-Bisau, Sudan, Denmark, Norway, Netherland, Finland and Sweden on some categories and species of birds [168]. But 3 mm lead pellet and 3.4 mm steel pellet each weighed 250 mg. Increasing diameter by 0.5 mm compensates for steel's lower density [169]. Over 90% of ammunitions manufactured in the world contain lead [170]. Pattern density is the primary factor that influences types of ammunition performance [171]. A high lead load (45–52 mg) per 100 g wet weight and the embedded pellet per body mass (1.21/100 g) in woodcock portend high health risk to consumers [172]. Exit wound caused by bullets are very rare at close range [173]. But sabot bullet made from lead alloy and plastic tends to be the most dangerous in soft and medium density materials. However, the effect of lead ammunition in non-quarry species of animals is unknown [174]. All these are very specific in forensic toxicology that can be relied upon in justice delivery, and provision of solution for criminal cases [175]. Hence forensic scientists play critical role in the determination of various risk factors in litigations related to the medical and legal cases [176], which are related to complete penetration of bullet into brain, that may cause death or incomplete penetration that may cause death or survival [177]. Hence, there is need to reduce level of lead exposure in overall population with a view to having healthy and safe environment [161], >0.1 mg/kg concentration has been reported for bovine, sheep, pigs and poultry, a dose that exceeds European Union Maximum level of 100 ppb [178], fulfilling the expectations of the community and justice [179], bearing in mind that wildlife could serve as source of potential lead bullet poisoning [3, 5, 173, 180–185]. Nevertheless renal damage could be confirmed legally by applying the reported investigation protocol [186]. European Chemical Agency (ECHA) has proposed a restriction on lead use in sports shooting, hunting and fishing. The restriction could reduce lead emissions by 630,000 tonnes over 20 years, representing 72% lead reduction [187].
