Bachelor Thesis Bachelor's Programme in Environmental Science, 180 Credits
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Bachelor Thesis Bachelor's Programme in Environmental Science, 180 credits Concentrations of lead, copper and zinc in forest soils near industrial areas Environmental Science, 15 credits Halmstad 2019-07-31 Éva Galyas HALMSTAD UNIVERSITY Abstract Environmental contamination with heavy metals, especially of soils, has been a continuous problem worldwide since the beginning of the industrial revolution. Heavy metal emissions have increased continuously since 1900 and the metals accumulate in the environment. Pulp and paper mill factories, and factories which produce sulphuric acid emit heavy metals, among others lead (Pb), copper (Cu) and zinc (Zn). Results from previous studies showed that the soils near factories had higher concentrations of these pollutants than the control place. In this study I want to determine the effects of industrial heavy metal emissions of one historic and one present industry on nearby soil heavy metal concentrations. Samples were taken near one historically heavily contaminated site, the old sulphite factory in Rydöbruk (1897-1944) and near the present Stora Enso paper mill in Hyltebruk. As a control site, I compared these with Rocknen nature reserve area. At each site I took 6 soil samples, representing the top 15-20 cm of soil and organic material. Samples were analysed with an Atomic Absorption Spectrometer and the concentrations of lead, copper and zinc were determined per ashed dry material. I analyzed the samples at the laboratory using the guideline from the Swedish Standard Institute for water analysis. The concentrations of the soil samples showed no significant difference between the nature reserve area and the industrial sites (One-way ANOVA). This was due to very variable organic content within and between the sites. Organic content of the samples has a significantly effect on the metal concentrations for Pb and Cu (Linear Regression test). In conclusion, metals can accumulate in the vegetation, and in case of Pb and Cu there is a correlation between their concentration and the amount of organic matter. Therefore in future studies it is best if soil with very high organic content or vegetation is used to determine if forest soil near industries are affected by past or present industrial emissions of heavy metals. Keywords: heavy metal, soil, paper mill, emission, human health, accumulation, toxicity, vegetation Summary Heavy metal contamination tend to be a challenge across the world because of their effect to the plants, animals, humans and ecosystem. Heavy metals are deteriorate the quality of atmosphere, water, soil and the human health. They can accumulate in vegetables/fruits grown in kitchen gardens near industries and they can accumulate in wild animals as well who are grazing in the forest, thus people who are living near industries have several ways to take up heavy metals via their food, which can affect their health. These pollutants can also deposit in the water bodies and affect wells. Soil pollution by heavy metals increases and the pollutants are accumulating and biomagnifying in the environment and in the organisms. Heavy metal contamination of food is a worldwide phenomenon and have a human health hazards, they are carcinogenic and may cause diseases related kidney, blood, cardiovascular and bone disease. The aim of this study to evaluate the contribution of industries to the environment with heavy metal pollution by comparing two areas near industries with a nature reserve area. The question is that are the heavy metal concentrations higher in the soil samples taken near the industrial area compared with the samples taken in the nature reserve area? To answer it i investigated three places in Halland and Kronoberg county in south Sweden. One of the industrial area is a pulp/paper mill in Hyltebruk, an other is a previous sulphite factory in Rydöbruk and the reference site is a nature reserve area called Rocknen. I took six samples from the three sampling places and prepared them for the analysis by drying first, and after placed them to the furnace to get rid of the organic matter in the soil. After the furnace i added nitric acid to each, placed them to the autoclave and filtered the liquid samples in to a volumetric flasks. When the samples were filtered I added deionized water to each so every samples were 100 ml. I analyzed the heavy metal concentrations by an Atomic Absorption Spectroscopy and performed a Statistical analysis for the results to find out it there are any significant difference between the places near the industries and the nature reserve area. To answer my questions I used One-Way ANOVA statistical test to analyze the results of the concentrations calculated for dry samples in each. The results have not shown significance for any of the metal concentrations in the different sampling sites. According the Linear Regression statistical test the concentrations of the metals are significantly correlate with the amount of organic mass for Pb and Cu, which suggests that heavy metals accumulate in the vegetation. It depends of the purpose of the land use to evaluate the target values for different exposure pathways, so to make sure about the target values and that the actual area meets with the desired conditions, need consider the target values for different kind of activities and exposure routes by taking contact with the authorities, local municipal agencies and the government who has their already existing data, different target values and the calculations for it, environmental laws and assessments to determine the suitabilities of land areas. Preface I was inspired to do this study because of my generally interest of ecotoxicology, heavy metals, their chemical behaviours and concentrations in the soil, environment and vegetation. I am grateful to my supervisor Antonia Liess who helped me during the work, helped with my project plan, for the recommendation for the study design to my work, with the calculations and even for coming with me to help take my samples in the industrial area in Rydöbruk. I want to thank for all help to my laboratory teacher Per Magnus Ehde who supported my work and provided me with tools in the laboratory, explained the layout of the analyze methods and the sequence. I am thankful also that I can write this thesis work with something I am interested in. I want thank for my classmate and friend Christel Yngve who were supporting me and always reminded me of important dates. Éva Galyas Lidhult 2019-05-22 Table of contents 1.Introduction 5 1.1 Background 5 1.2 Hypothesis 6 1.5 Delimitation 7 2. Methodology 8 2.1 Literature research 8 2.2 Study site and study design 9 2.4 Field sampling 10 2.5 Sample preparation and laboratory analyses 10 2.6 Calculations 11 2.7 Statistical analyses 12 3. Results 13 3.1 Heavy metal concentration in dry samples at the different sampling sites 13 3.2 Metal concentrations in dry weight in relation to the organic content of the samples 15 4. Discussion 18 4.2 Uncertainties 19 4.1 Environmental goals 20 5. Conclusion 22 Proposals for further research 22 References 23 Appendix 1 26 Appendix 2 31 Appendix 3 33 1.Introduction 1.1 Background Soil pollution with heavy metals caused by different industries is a continuous issue since the industrial revolution worldwide (Liu et al., 2017). The consequence of these activities is the deposition of heavy metals on top soils and water bodies (Agoumo et al., 2017). Heavy metal contamination of the biosphere has increased since 1900 because metal leftovers accumulate in the environment. Pulp and paper mill factories contribute to the heavy metal emissions such as zinc (Zn), copper (Cu), chrome (Cr), cadmium (Cd), iron (Fe) and lead ( Pb). Samples taken near a paper factory tend to show higher concentrations than the samples from a reference site (Adoli et al., 2010). Factories producing sulphuric acid may emit elements with potential for adverse environmental impacts. The extraction of sulphur produces a hematite-rich waste which calls roasted pyrite ash and the procedure emits a number of potentially polluting elements such as Cu, Pb and Zn (Oliveira et al., 2012). Therefore are the industries seems to be contribute heavily to soil pollution. The soil serves as a reservoir of contaminations because it receives huge amount of pollutants from different sources and the soil is considered to be the main recipient for heavy metal pollution because these pollutants are depositing there (Agoumo et al., 2017), and the main recipient of the atmospheric metal pollutants is the topsoil (Adoli et al., 2011). Soils can be used as a diagnostic tool to evaluate the environmental conditions of an area because of its capacity to receive the pollutants (Navarrete et al., 2017). Zn and Cu are essential metals for organisms but in too high concentrations can have deleterious effects. Pb is toxic even in low concentrations to all life forms (Schneider et al., 2018). For that reason the conditions of the soils can affect several factors such as health and ecosystem. All heavy metals are dangerous to the human health in the form of their cations and if they are bonded to short chain of carbon atoms (Baird et al., 2008). As Singh et al., (2017) says, these metals have negative effects on neurological system, arterial system of the human kidneys, adverse changes on the gastrointestinal system and it can disrupt the transport activities of the phosphate bio-compounds. Pb and and Zn have a potential to affect the neurological system, kidney function, ossification process and other organs (Singh et al.,2017). Lead exposure is associated even with the damages in the human central nervous system and kidneys, having impact on psychological and neurobehavioral functions ; causes oxidative stress and several chronic diseases and copper exposure causes damages in proteins and lipids (Dong et al., 2017).