The study area is the city of Zintan, in northwestern Libya, which has grown over the past

30 years. Its current population is roughly 30,000. Although the city is in part commercial, most

of the population engages in agriculture and primarily grows cereal crops (wheat and barley). The

demand of the growing city for agricultural products has increased, intensifying the use of fertilizers,

pesticides, and insecticides. Consequently, concentrations of potentially toxic elements (PTE) in

the soil have increased. To assess the soil quality (to provide a snapshot of the condition of the

soil), systematic sampling was undertaken across a grid of about 2 km  2 km. The main objective

was to determine the chemical and mineral composition of the area of interest, keeping in mind

the geological footprint of the terrain. The geologic framework itself is not conducive to elevated

concentrations of elements like U, Th, Mo, As, Hg, Pb, and Cr. Therefore, metal concentrations

greater than the amounts in the Earth’s crust are most likely of anthropogenic origin. A total of

143 samples were collected and chemical analyses were performed using a Thermo Fisher Scientific

Niton XL3t GOLDD+ XRF analyzer for the following elements: Mo, Zr, Sr, U, Rb, Th, Pb, Au, Se,

As, Hg, Zn, W, Cu, Ni, Co, Fe, Mn, Cr, V, Ti, Sc, Ca, K, S, Ba, Cs, Te, Sb, Sn, Cd, Pd, and Ag. This

paper provides examples of elevated concentrations, potentially harmful to the environment, such as

those of the following: sulfur of unknown origin (two to three times higher than the Earth’s crust

average); arsenic, given that there are no related natural phenomena (all the samples measured

displayed concentrations higher than those found in the Earth’s crust); mercury (concentrations much

higher than permissible levels); cesium (additional investigations required to determine the origin);

molybdenum; and uranium likely resulting from the use of superphosphates (concentrations nearly

always significantly higher than those in the Earth’s crust).

Global population is growing rapidly. As a result, increasingly large areas are being settled and

farmed. This devastates soils and causes pollution by heavy metals and other components. Heavy metals in

the environment originate from both natural and anthropogenic sources. Natural sources generally include

rock weathering and the propagation of heavy metals, such as Cr and Ni, from ultrabasic rocks. These are natural

processes that generally do not threaten human health. Anthropogenic sources include industry and inappropriate

disposal of waste in the environment. In such cases concentrations of heavy metals can be harmful

to people and other living beings. Al Zintan is a city located in northwestern Libya, on a plateau mainly built

up of Cretaceous sediments. Since the 1980’s, nomadic population has rapidly been settling this area. As a

result, a former part of the desert was transformed and is used for farming. Soil sampling at Al Zintan was

conducted in 2017, across a 2×2 km grid. A total of 143 samples were collected from depths of about 30 cm.

The samples weighed 2 to 2.5 kg and generally comprised sand with a clay component. A Niton Xl3t goldd+

instrument was used for chemical analyses, based on which GIS heavy-metal distribution maps were generated.

The distribution of Cr, Ni, Cu and Zn is discussed on the paper.