Conifer needles have been extensively studied worldwide, particularly in regions impacted by heavy metal pollution from traffic and industrial activities. These studies focus on evaluating the potential of pine needles as bioindicators of environmental contamination, due to their year-round presence. In addition to industrial pollution, shooting ranges are another significant source of heavy metal contamination.
Shooting ranges provide a controlled environment for firearm practice and training, yet the environmental impacts of these activities are often overlooked. The discharge of lead and other heavy metals from ammunition poses a serious threat to ecosystems and public health. Lead is a major contaminant, as bullets are typically composed of lead or contain lead-based components. When fired, these bullets release lead particles into the environment, contaminating soil and water. Over time, the accumulation of lead in the ecosystem can have harmful effects on plants, wildlife, and human health.
One such area of concern is the Munkatorp Shooting Range in Örebro, Sweden, which has been identified as a site of significant heavy metal pollution. Although there are plans for decontamination, no substantial actions have been taken to address the contamination so far. Within the designated area, four trees were selected for sampling: two Norway spruces (Picea abies) and two Scots pines (Pinus sylvestris). Needle samples were carefully collected and stored in plastic bags, then washed, dried, and ground into a fine powder for subsequent digestion and analysis. The metal content was quantified using inductively coupled plasma mass spectrometry (ICP-MS) after acidic digestion. The study focused not only on metals commonly associated with ammunition, specifically manganese, iron, nickel, copper, zinc, molybdenum, antimony, and lead, but also on essential elements for plants to better understand the environmental impact of the pollution in this area. Furthermore, the needles underwent analysis via Raman Spectroscopy to get information on the metabolic state of the plant material, which provides deeper inside on the soil conditions on the growing site of the conifers. The analysis of conifer needles revealed no significant contamination attributable to the shooting range. Instead, it highlighted species-specific variations in metal contents, but within the ranges reported in literature. Species-specific differences were also found using Raman Spectroscopy.
2025.