Biochar is a carbonized material obtained from the pyrolysis of biomass produced in a limiting environment of zero or very low oxygen. Its interest lies in its versatility for different applications in the water treatment, soil pollution, mitigation of greenhouse gases, etc. The synergy of this product with other amendments such as compost has been studied for different applications in the soil, including environmental remediation, crop yield, etc. The aim of the research is to identify the relevant aspects in the scientific literature of biochar, compost and soil through a bibliometric analysis for which 753 articles were selected from the Scopus database, having as keywords “biochar”, “compost” and “soil”. This research used R software, specifically the package Bibliometrix, to analyze descriptive analysis, author sources, document metrics, citation, co-citation analysis, co-occurrence network, co-word analysis, and collaboration analysis. Results showed that Zhang Z is the author with the greatest number of documents, and with a higher H index. Science of The Total Environment, Bioresource Technology, and Agronomy are the 3 topmost relevant sources. The keywords according to bond strength and most frequent use were biochar (538 occurrences), composting (349 occurrences), compost (436 occurrences), charcoal (295 occurrences), soil (255 occurrences). China is the country with the most collaboration. It is hoped that the bibliometric review will help to identify current research trends and provide information on the application of biochar and compost in the soil.

This research aims to evaluate the economic valuation of lead air pollution in the AA.HH. Virgen de Guadalupe, Callao, Peru. A survey was conducted with 182 residents, focusing on air quality, temporary exposure to pollution, aesthetic appreciation of the environment, willingness to accept (WTA) economic compensation, and willingness to pay (WTP) to mitigate lead air pollution. The data were analyzed using the logit model through STATA16 software. The results revealed that 62.09% of respondents were willing to accept economic compensation, while 56.04% expressed willingness to pay for reducing lead pollution. Furthermore, it was determined that the average monthly WTP is PEN 62.48 (USD 16.47), amounting to PEN 1,201,865.28 (USD 329,103.16) annually for the entire population of 1603 residents. In contrast, the average monthly WTA per resident is PEN 153.59 (USD 40.48), totaling PEN 2,954,457.24 (USD 809,010.16) annually due to lead air pollution. The study concluded that environmental perception, awareness, the desire to maximize present utility, and uncertainty about the future significantly influence the economic valuation of lead air pollution in this community.