The application of the vermicomposting process in the bioremediation of diesel contaminated soils

Abstract

Polycyclic Aromatic Hydrocarbons (PAHs) are among the environmental pollutants that have very high carcinogenic and mutagenic activity. Among hundreds of different PAHs, 17 are considered priority pollutants and routinely monitored for regulatory purposes. Extended periods of exposure and expensive clean-up costs are typically associated with the vast majority of processes used for the remediation of areas contaminated with PAHs. The results of this study indicate that bioremediation via vermicomposting could be an effective method for remedying soils contaminated with toxic organic compounds, such as PAHs. This study was conducted over 90?days in the presence of various quantities of organic matter (cattle manure) to recover soils contaminated with PAHs. High-performance liquid chromatography (HPLC) was applied to identify PAHs. An evaluation of the toxicity of the final material and the transformation of the organic matter throughout the process was also conducted. The data presented here suggest a relationship between the molar mass of the PAHs and the ability of the vermicomposting process to promote biodegradation. These results suggest that vermicomposting has great potential to be utilized as a tool for the bioremediation of soils impacted by PAHs.     

Levels and risks of particulate-bound PAHs in indoor air influenced by tobacco smoke: a field measurement

Considering tobacco smoke as one of the most health-relevant indoor sources, the aim of this work was to further understand its negative impacts on human health. The specific objectives of this work were to evaluate the levels of particulate-bound PAHs in smoking and non-smoking homes and to assess the risks associated with inhalation exposure to these compounds. The developed work concerned the application of the toxicity equivalency factors approach (including the estimation of the lifetime lung cancer risks, WHO) and the methodology established by USEPA (considering three different age categories) to 18 PAHs detected in inhalable (PM₁₀) and fine (PM_2.5) particles at two homes. The total concentrations of 18 PAHs (Σ_PAHs) was 17.1 and 16.6 ng m^?3 in PM₁₀ and PM_2.5 at smoking home and 7.60 and 7.16 ng m^?3 in PM₁₀ and PM_2.5 at non-smoking one. Compounds with five and six rings composed the majority of the particulate PAHs content (i.e., 73 and 78 % of Σ_PAHs at the smoking and non-smoking home, respectively). Target carcinogenic risks exceeded USEPA health-based guideline at smoking home for 2 different age categories. Estimated values of lifetime lung cancer risks largely exceeded (68–200 times) the health-based guideline levels at both homes thus demonstrating that long-term exposure to PAHs at the respective levels would eventually cause risk of developing cancer. The high determined values of cancer risks in the absence of smoking were probably caused by contribution of PAHs from outdoor sources.     

The impact of the board of directors on business climate change management: case of Brazilian companies

Mitigation and Adaptation Strategies for Global Change - The corporate sector is one of the main emitters in the world due to the production process and therefore is identified as a major...