Abstract—This study evaluates the health risks associated
with exposure to atmospheric emissions from energy recovery of
cashew nut shells through pyrolysis and combustion processes.
The analysis focuses on two risk categories: carcinogenic risks,
assessed by the Individual Risk Excess (ERI), and noncarcinogenic
risks, estimated by the Hazard Quotient (HQ).
Samples were collected at the source (industrial chimney) using
isokinetic sampling on activated carbon tubes and subsequently
analyzed by gas chromatography coupled with mass
spectrometry to identify and quantify Volatile Organic
Compounds (VOCs). These concentrations were then modelled
at 500 meters using an atmospheric dispersion model of the
Screening Modelling in Air Quality Assessment type. The results
show that benzene and 1,3-butadiene are the primary
contributors to carcinogenic risks, with a total ERI exceeding
the acceptable threshold of 10⁵. For benzene, direct combustion
poses approximately 1.7 times the risk compared to pyrolysis.
Similarly, 1,3-butadiene shows a risk reduction with pyrolysis
(about 1.3 times lower). Overall, pyrolysis reduces the total
carcinogenic risk by 26.9% when compared to direct
combustion. Regarding non-carcinogenic risks, the Hazard
Quotients (HQ) for toluene (4.38×10−5 for combustion and
4.03×10−5 for pyrolysis) and styrene (5.8×10-4 for combustion
and 1.9×10-4 for pyrolysis) remain below 1, indicating limited
short-term health effects. Comparing the two recovery processes,
the overall hazard quotients show a slight reduction of 11.1%
between direct combustion and pyrolysis of cashew nut shells.
The study recommends technological improvements and strict
regulatory measures to sustainably manage emissions
sustainably, thereby protecting public health and the
environment.
Keywords—energy valorization, cashew nut shells, Volatile
Organic Compounds (VOCs), health risks, modelling in air
quality assessment, pyrolysis and combustion
Cite: Anselme Bagoro, Marie Sawadogo, Anthony Benoist, Sayon dit Sadio Sidibe, and Igor W.K. Ouedraogo, "Energy Valorization of Cashew Nut Shells: Characterization of Volatile Organic Compounds and Quantitative Health Risk Assessment in Pyrolysis and Direct Combustion Processes," International Journal of Environmental Science and Development vol. 16, no. 6, pp. 419-425, 2025.
Copyright © 2025 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).