Toxicological analysis of phthalates from dust samples underneath selected Light Rail Transit 1 (LRT1) stations using the Zebrafish Embryotoxicity (zfet) test

Abstract

Phthalates are the most common form of plasticizers. Due to the ease with which phthalates diffuse from their plastics and the sheer volume of plastics that have been introduced to the environment, they represent one of the most ubiquitous and persistent chemicals known. Phthalates are known to have several toxic effects. The study was carried out to identify the phthalates found in the urban dust that have accumulated underneath the LRT1 stations at Monumento, R. Papa, and EDSA in Metro Manila, and to determine the potential embryotoxic effects of these phthalates. The urban dust samples were subjected to solid phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS). Six phthalates were identified, and the extract was then used in the zebrafish embryotoxicity (ZFET) test. Lethal and sublethal endpoints were observed in the zebrafish embryos. The dilutions 1:0 and 1:2 were found to be highly embryotoxic to the embryos and a dose-response relationship was seen in dilutions ranging from 1:4 to 1: 40 with a decrease in the number of deaths and abnormalities as the dilution gets higher, and the findings were found to be statistically significant. The LC50 of the phthalate mixture was found to be equivalent to a concentration of 9.188 µg/ml. This study therefore elucidated some of the toxic effects of the phthalates, but further studies must be performed to evaluate the toxicity of the individual phthalates, some of whose effects are relatively unknown. This information can then be used in the development of policies dealing with waste disposal and public health.