# LCA as a Tool for the Environmental Management of Car Tire Manufacturing
## 4 Results and Discussion
### Eco-Indicator 99  
Table 2 presents the results of the characterization of environmental consequences occurring in the material life cycle of a traditional and ecological car tire based on impact categories. Among substances detrimental to human health, these were the inorganic compounds causing respiratory diseases that were established to have the highest negative impact. Their maximum emissions levels were obtained in the use-stage of the traditional tire (\(1.09\times 10^{-3}\) DALY). The analyses indicate that the recycling processes would result in the reduction of their environmental impact over the entire life by a total of \(8.54\times 10^{-7}\) DALY, and in the case of the ecological tire by a total of \(1.49\times 10^{-6}\) DALY. Among the factors of a negative effect on animal health and life, ecotoxic substances were determined to be the leading cause of hazard. Their emissions reach the highest level in the production of the traditional tire (\(2.90\times 10\) PAF \(\times\) m\({}^{2}\times\) year). Recycling at the end of the product use stage of the life cycle would minimized the negative impact by \(2.87\times 10^{-1}\times\) PAF \(\times\) m\({}^{2}\times\) year in the conventional tire and \(4.66\times 10^{-1}\times\) PAF \(\times\) m\({}^{2}\times\) year in the eco-tire. Considering the hazards to plant organisms, the strongest negative effect is concerned with acidification or eutrophication of the natural environment. The highest level of the compound emissions responsible for these effects relate to the use of the traditional tire (\(3.64\times 10\) PDF \(\times\) m\({}^{2}\times\) year). Recycling would reduce the negative impact by a total of \(4.45\times 10^{-2}\) PDF \(\times\) m\({}^{2}\times\) year (the traditional tire) and by \(-7.83\times 10^{-2}\times\) PDF \(\times\) m\({}^{2}\times\) year (the ecological tire). Considering elevated energy consumption on account of raw material extraction, the highest level of harmful impact in this respect was recorded in fossil fuels. As in the previous cases, the most resource-engaging phase was the use of the traditional tire (\(4.11\times 10^{3}\) MJ). It was estimated that over the entire life cycle of the traditional tire, recycling would introduce total energy savings amounting to \(5.95\) MJ, and in the eco-tire \(8.32\) MJ. One of the key purposes of LCM is to determine elements in the life cycle of a given product that exert the heaviest impact on the environment. In traditional and ecological tires, the impact categories that were shown to have the most substantial negative consequences for the environment are, in the order of magnitude, the extraction of fossil fuels (an aggregate score for the traditional tire was \(100.87\) Pt and \(94.82\) Pt for the eco-tire), emissions of respiratory inorganic substances (\(33.32\) Pt--the traditional tire, \(30.71\) Pt--the eco-tire), emissions of compounds causing climate change (\(14.19\) Pt--the traditional tire, \(13.14\)--the eco-tire), and acidification/eutrophication emissions (\(3.21\) Pt--the traditional tire, \(2.97\) Pt--the eco-tire). For both tire technologies, the highest negative emission rates occurred in the use stage (Figure 5). Table 3 shows the grouping and weighting results concerning the environmental impact at particular stages of the traditional and ecological tire life cycle, divided into impact categories. The negative environmental impact was the highest in the fossil fuel extraction. The total ecological burden of this activity was estimated in the traditional tire at \(97.8\) Pt, and \(92.7\) Pt in the case of the eco-tire technology. Recycling is likely to cause a \(0.14\) Pt reduction in the environmental impact of the traditional tire life cycle, and a \(0.2\) Pt decrease in the ecological tire. Considering the secondary factors, it was found that inorganic substances linked to respiratory diseases and compounds that cause climate change also exhibit a particularly adverse impact on the environment.