Heavy metal contamination in Peru: implications on children's health.

Cerro de Pasco, Peru, has been excessively contaminated with heavy metals due to high mining activities in the region. We investigated the presence of chronic exposure to heavy metals in children living in Cerro de Pasco and its effect on health. Heavy metal concentrations were determined in hair samples collected from 78 children living in a region exposed to an open-pit mine (Paragsha region) and from other 16 children unexposed to mine activities (Carhuamayo region). Children exposed to the mine showed statistically significant higher concentration of aluminum, antimony, arsenic, cadmium, chromium, iron, lead, tin and thallium (p < 0.05) than control children. Hair samples collected from the same children in two occasions (2016 and 2018) showed that the exposure is chronic with higher levels of heavy metals observed in 2018. The concentration of heavy metals was higher in hair tip than in hair root samples. Heavy metals are associated with substantial higher risk of nosebleed (odds ratio, OR = 15.40), chronic colic (OR = 7.30), dermatologic alterations (OR = 6.16), mood alterations (OR = 7.07), presence of white lines on nails (OR = 12.10), reduced visual camp (OR = 3.97) and other symptoms (OR = 5.12). Chronic heavy metal exposure implies various negative consequences on children's health. Preventive measures are crucial to protect children's health.

Estimation of the post-mortem interval: Effect of storage conditions on the determination of vitreous humour [K+].

Obtaining a reliable estimate of the post-mortem interval (PMI) has been a long-running challenge in forensic medicine. Several more or less successful techniques for making such estimates have been developed, but in recent years important advances have been made thanks to the detailed study of the relationship between the PMI and the analytes - in particular K+ - of the vitreous humour (VH). The extraction and pre-treatment of VH samples has been standardized, the influence of certain environmental factors on analytical results has been quantified, and some of the circumstances under which techniques become unreliable have been identified. The present work examines how the conditions to which VH samples are subject in routine practice may alter the results of their analysis. Exposure to light and ambient temperature was found to alter the values returned in determinations of VH [K+], [Na+] and [Cl-], while exposure to several freezing/thawing cycles (even with final heating) led to no significant modifications in determinations of VH [K+] and [Na+]. It is recommended that if analysis has to be delayed, VH should be frozen for storage in a refrigerator before bringing to room temperature for processing. It is also recommended that samples not be exposed to ambient light and temperature.