Detection of microplastics using a DSLR lens-based UV imaging system

Abstract

Microplastics (MPs) are plastic derivatives, typically less than 5 mm but greater than 1 μm. With studies showing that these particles can cause cellular damage in living organisms when ingested, MPs pose an increasingly prevalent health concern in addition to its environmental harm. Moreover, despite the alarming extent of MPs found in bodies of water, there is very little research done on the extent of MP contamination in the Philippines. Hence, there is a need to develop a means of MP identification that is both efficient and accessible. This study, in particular, seeks to detect and identify MPs by using a DSLR lens attached to a UV CCD camera in order to capture images of the sample under UV illumination with a wavelength of 396 nm. From this, the images were segmented via a normalized threshold and each sample's total surface area was calculated. The samples were also captured under white light illumination, serving as the control setting. The experiment found that samples were generally brighter under UV illumination in comparison with white light illumination, showing a higher mean gray value, higher detected surface area from the sample, and higher histogram distributions of brighter pixels.