A Dynamic Integrated Analysis of Truck Tires in Western Europe

By evaluating tires from a perspective of industrial metabolism, potential novel and practical ways to reduce their environmental impact can be found. This may be achieved by focusing on technological issues such as choosing materials, designing products, and recovering materials, or by looking at institutional and social barriers and incentives such as opening waste markets or changing consumer behavior. A model is presented for the life cycle of truck tires in Western Europe that is dynamic in nature and values both environmental and economic consequences. Various scenarios are simulated including longer tire lifetimes, better maintenance of tire pressure, increased use of less-expensive Asian tires, and increased use of fuel efficiency-enhancing tires ("eco-tires"). Tentative results indicate that, among other things, more than 95% of the overall environmental impact during the life of a tire occurs during the use of the tire, due to the impact of tires on automotive fuel efficiency. Better maintenance of tire pressure and use of eco-tires produce greater environmental and economics benefits than more-durable and/or less-expensive (Asian) tires. These results imply that the emphasis in environmental policies related to tires should shift from the production and the waste stages to the consumption stage. It also suggests that the focus on materials throughput and associated improvements through factor 4 or factor 10 advances in reduction in mass are less important than the quality of the tires and their management.     

Evaluation of the Tire Industry of China based on Physical Input–Output Analysis

With the rapid development of the rubber industry and its downstream sectors in China, the resulting sharp increase in the number of scrap tires is creating great environmental pressure. By considering the tire production, consumption, collection, and reuse processes as a whole system of tire material flows, and based on physical input–output analysis (IOA), this article analyzes the status quo of China's tire industry and performs a comparative study between China and Europe. The study shows that the tire industry of China in 2005 and that of Europe in 1996 are similar in material‐flow characteristics. To make the best use of materials, it is necessary to strengthen the reuse of scrap tires in China. A scenario analysis is presented to show the effects of improving the reuse process from the viewpoint of IOA.     

A lateral dynamics of a wheelchair: identification and analysis of tire parameters

In vehicle dynamics studies, the tire behaviour plays an important role in planar motion of the vehicle. Therefore, a correct representation of tire is a necessity. This paper describes a mathematical model for wheelchair tire based on the Magic Formula model. This model is widely used to represent forces and moments between the tire and the ground; however some experimental parameters must be determined. The purpose of this work is to identify the tire parameters for the wheelchair tire model, implementing them in a dynamic model of the wheelchair. For this, we developed an experimental test rig to measure the tires parameters for the lateral dynamics of a wheelchair. This dynamic model was made using a multi-body software and the wheelchair behaviour was analysed and discussed according to the tire parameters. The result of this work is one step further towards the understanding of wheelchair dynamics.     

End‐of‐life product management as a resilience driver for developing countries: A policy experiment for used tires in Ecuador

Over the last decades, a number of new environmental policies have been designed to improve waste management. Among them, extended producer responsibility (EPR) has introduced a mechanism to shift the environmental and financial burden of end‐of‐life products from public management to producers. Recently, EPR has been adopted by a growing number of developing countries, but this policy often struggles in being effectively implemented in such contexts, missing the opportunity of using waste management as a sustainability driver. By discussing the EPR for end‐of‐life tires (ELTs) in Ecuador, this paper proposes a different approach in designing and implementing EPR schemes in developing countries: it recommends consideration of social sustainability, rather than merely copying foreign management frameworks. To address this point, two case studies on socially directed ELT applications were designed and carried out. The case studies aimed at improving resilience of vulnerable populations to natural disasters by increasing the resistance of housing and settlements against catastrophic events using civil engineering applications. The analysis of the case studies’ outcomes brings to light possible policy adjustments, in which social sustainability goals are taken into account within the national EPR scheme. The Ecuadorian case also highlights the benefit of employing an adaptive governance approach when dealing with challenging urban management topics, such as informality (a widespread phenomenon in developing countries) and resilience.     

LATEX: A peculiar biological component in airborne particles?

In a study in the USA, latex allergens have beenidentified in airborne particles. Natural rubber(latex) is a product from the plant Heveabrasiliensis and is largely used in the tireindustry. In the vicinity of roads, latex can becomeairborne due to wear-off processes of tires.Sensitisation to latex has been increasing in the lastdecade; an important pathway for the sensitisation ismediated by the airways. It is not known, if thisconcerns mainly laboratory personnel or if this isalso an environmental problem.This study investigated the content of latex inairborne particles in the vicinity of a road withmoderate traffic, in comparison to a control site.Latex was determined in a competitive ELISA based onpolyclonal IgE antibodies. During spring and summer,collected airborne dust was analysed for the contentof protein and latex. Latex concentrations inPM₁₀ in the city were higher than at the controlsite. At both sites, latex levels were significantlylower in PM_2.5 than in PM₁₀.     

Ecological Aspects of Artificial Reef Construction Using Scrap Tires

The paper presents the experimental study of the effect of scrap tire rubber leachates on the production characteristics of two ecological groups of water plants, the phytoplankton Monochrysis lutheri, Phaeodactylum tricornutum, and Exuviaella pusilla and the macrophytes Ulva rigida, Polysiphonia sanguinea, P. denudata, and Ulothrix sp. Data are presented on the dynamics of leachate (zinc, copper, oil products, paraformaldehyde, and acetone) diffusion into the environment from tire rubber preexposed to seawater for various periods of time. The data on leachate effects on the phytoplankton and macrophytes in the Black Sea are discussed. Leachates from fresh (not preexposed to seawater) rubber were found to have the largest impact on the production parameters of water plants. Leachates from rubber preexposed to water for various periods of time produced a significant effect on the production parameters at the initial stages of rubber exposure to water. Taking this into account, the authors argue that scrap tire utilization in artificial fouling substrate construction in heightened trophicity waters should be cautiously controlled to prevent the waters from secondary contamination.     

Tire Rubber Recycling and Bioremediation: A Review

The accumulation of, and environmental hazards associated with, tire rubber and its disposal are major global concerns. The complex composition and structure of tire rubber and its additives make it highly resistant to natural degradation, but recently, microbial methods of detoxification and degradation of tire rubber have been developed. The polymers in tire rubber can be devulcanized by the activity of aerobic and anaerobic microbes and both the metabolic pathways and associated enzymes involved are becoming better known. Combining and adapting different rubber treatment processes could ultimately lead to more efficient ways of degrading and recycling tire rubber waste.     

Testing Predictions of Displacement of Native Aedes by the Invasive Asian Tiger Mosquito Aedes Albopictus in Florida, USA

The Asian Tiger Mosquito Aedes albopictus arrived in the USA in 1985 in used automobile tires from Japan and became established in Texas. This species has since spread to become the most abundant container-inhabiting mosquito in the southeastern USA, including Florida, where it has reduced the range of another non-indigenous mosquito, Aedes aegypti. To assess the accuracy of predictions that A. albopictus would competitively exclude the native Eastern Treehole Mosquito Aedes triseriatus from tires but not from treeholes (Livdahl and Willey (1991) Science 253: 189–191), we extensively monitored the abundances of mosquito immatures before and after the Asian Tiger invaded these habitats in south Florida. These field data failed to demonstrate exclusion of A. triseriatus from treeholes following the establishment of A. albopictus in this microhabitat in 1991. However, A. albopictus had significantly higher metamorphic success and showed a significant increase in mean crowding on A. triseriatus in treeholes monitored from 1991 to 1999. In urban and suburban sites, A. triseriatus was uncommon in abandoned tires even before the arrival of A. albopictus. In some wooded sites, there is evidence for a decline in numbers of A. triseriatus in used tires and cemetery vases, but the native species has not been excluded from these habitats. Overall, the negative effect of A. albopictus on A. triseriatus has been less severe than that on A. aegypti. Experiments outdoors in surrogate treeholes showed that A. albopictus was more successful than A. triseriatus in survival to emergence in the presence of predatory larvae of the native mosquito Toxorhynchites rutilus when first instar predators encountered both prey species shortly after their hatch. Eggs of A. albopictus also hatched more rapidly than those of A. triseriatus, giving larvae of the invasive species an initial developmental advantage to escape predation. Biological traits that may favor A. albopictus are offset partly by greater treehole occupancy by A. triseriatus and the infrequency of the invasive mosquito species in undisturbed woodlands, which mitigates against displacement of the native mosquito in these habitats.     

Degradation of the rubber in truck tires by a strain of Nocardia

A strip of tread compound cut from a truck tire was degraded only slightly when it was used as the sole growth substrate for a strain of Nocardia. On the contrary, its degradation was markedly enhanced by addition of a strip cut from a latex glove which the organism readily utilized as a growth substrate. When a glove strip was added, the biomass concentration in the experimental flask became more than 10-fold higher than the control without a glove strip and the colonization of the tire strip was significantly enhanced.After 8 weeks' cultivation, about 28% of the tire strip was disintegrated into very small black particles (mostly less than 30 m in diameter) and the weight of the remaining unchanged portion of the strip was about 49% of the initial weight.Four kinds of truck tire treads were attacked in differing degrees by the organism under the same conditions. The treads containing more than 70 phr (parts per hundred of rubber) of natural rubber were considerably attacked, while those with a natural rubber content of less than 55 phr were attacked only slightly. The microbial activity against the rubber in the side wall of a truck tire was relatively high, but the inner liner was hardly attacked and the bead rubber not at all.     

Distribution,Levels, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Singed Cattle Hide

Human beings are exposed to polycyclic aromatic hydrocarbons (PAHs) from various occupational, environmental, and dietary sources. The study was carried out in the Cape Coast Metropolis of Ghana to assess the levels of PAHs in treated and untreated cattle hide and the associated health risks thereof. Treated cattle hide (wele) is one of the most well-patronized meat products in Ghana. A total of 90, treated (n = 36), untreated (n = 36), and control (n = 18) cattle hide samples were treated and analyzed using a gas chromatography flame ionization detection (GC/FID) technique. The total PAH concentration in the treated cattle hide ranged from 5.9 μg/kg naphthalene to 719.9 μg/kg benzo[b]fluoranthene. The total PAHs in untreated hide ranged from 57.6 μg/kg naphthalene to 19840.9 μg/kg benzo[b]fluoranthene. The amount of PAHs in the control hide, however, ranged from non-detectable for many of the PAHs to 0.5 μg/kg for fluorene. The carcinogenic risk value associated with the consumption of treated hide in children ranged between 1.0 × 10^?3 and 9.4 × 10^?3 whereas that of adults ranged between 1.9 × 10^?4 and 2.1 × 10^?5. This implies that the continuous consumption of heavily burnt cattle hide may not exempt the consumers from all the possible health cases associated with PAHs.