Human health risk assessment of lead, cadmium, and mercury co-exposure from agricultural soils in the Tuzla Canton (Bosnia and Herzegovina)

Abstract

The aim of this study was to assess the risk of human exposure to lead (Pb), cadmium (Cd), and mercury (Hg) through agricultural soil by considering both uncertainty and variability in key exposure parameters. For this reason we collected soil samples from 29 locations in the Tuzla Canton (Bosnia and Herzegovina) and measured their metal levels with inductively coupled plasma atomic emission or absorption spectrometry (ICP-AES and ICP-AAS, respectively). The levels of Pb ranged from 13.33 to 1692.33 mg/kg, of Cd from 0.05 to 3.67 mg/kg, and of Hg from 0.02 to 2.73 mg/kg. To estimate cancer and non-cancer risks we used deterministic and semi-probabilistic methods. Lead was found to involve higher health risk than the other two heavy metals. Its hazard index (HI) decreased between population groups (children>women>men) and exposure routes (ingestion>skin contact>inhalation). Our Monte Carlo simulations indicated that Pb HIs for both adult populations had a 0.6 % probability to exceed the threshold value of 1, while in children this probability was 14.2 %. Cd and Hg showed no probability to exceed the threshold in any scenario. Our simulation results raise concern about possible adverse health effects of heavy metals from soil, especially in children. It is very important to continue monitoring environmental pollution and assess human health risk, not only with respect to soil, but also with other important environmental compartments, such as air and water.

Cilj ovog istraživanja bio je procijeniti izloženost ljudi olovu (Pb), kadmiju (Cd) i živi (Hg) iz poljoprivrednog tla, uzimajući u obzir pridružene nesigurnosti i varijabilnosti u ključnim parametrima izloženosti. Primjenom metoda induktivno spregnute plazme i atomske emisijske ili apsorpcijske spektrometrije (ICP-AES i AAS) određena je koncentracija metala u uzorcima poljoprivrednoga tla prikupljenog s 29 lokacija u Tuzlanskom kantonu (Bosna i Hercegovina). Koncentracije Pb kretale su se u rasponu od 13,33 do 1692,33 mg/kg, Cd od 0,05 do 3,67 mg/kg i Hg od 0,02 do 2,73 mg/kg. Za procjenu kancerogenog i nekancerogenog rizika koristili smo se determinističkim i semiprobabilističkim pristupom u procjeni rizika. Utvrđeno je da Pb doprinosi povećanom zdravstvenom riziku više nego druga dva teška metala. Indeks opasnosti (eng. hazard index ‒ HI) smanjivao se među populacijskim skupinama (djeca > žene > muškarci) i putevima izloženosti (ingestija > dermalni kontakt > inhalacija). Naše Monte Carlo simulacije pokazale su da HI za Pb uključujuči obje populacije odraslih imaju 0,6 % vjerojatnosti da će prijeći vrijednost praga od 1, dok je u djece ta vjerojatnost bila 14,2 %. Vjerojatnost da će premašiti prag u bilo kom scenariju nisu pokazali Cd i Hg. Rezultati naših simulacija izazivaju zabrinutost zbog mogućih štetnih učinaka teških metala iz tla, posebice u djece. Vrlo je važno nastaviti pratiti onečišćenje okoliša i procijeniti rizik za zdravlje ljudi, ne samo putem tla, već i putem drugih značajnih dijelova okoliša, poput zraka i vode.