Levels, distribution, sources and human exposure pathways of alkylphenol and alkylphenol ethoxylates in indoor dust in Turkiye.

Environmental phenolic chemicals, due to their widespread occurrence and potent estrogenic properties, pose a risk to human exposure. The phenolic organic contaminants alkylphenols (APs) and alkylphenol polyethoxylates (APEs) are used in various household applications, and they may enter to the environment during production and use, potentially appearing in indoor dust. However, little is known about the levels of environmental phenolics in indoor environments. In this study, five of these compounds namely octylphenol (OP), 4-Octylphenol Monoethoxylate (4-OPME), 4-tert-octylphenol (4-t-OP), 4-n-nonylphenol (4-n-NP) and nonylphenol diethoxylate (di-NPE) were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in household dust samples (n = 148) collected from Ankara, the capital of Turkiye. OP and 4-OPME was not present in any of the analyzed samples. The median concentrations of the 148 settling dust samples were 35, 520, and 1910 ng g dust for 4-t-OP, 4-n-NP, and di-NPE, respectively. An assessment of the human (children and adults) exposure pathway to APs and APEs, which are recognized as endocrine-disrupting chemicals found in residential dust, revealed that it was approximately 3 times higher for children than for adults at both moderate and heavy exposure levels. The association between chemical exposure, house characteristics, and family lifestyle was investigated using a multivariate logistic regression model. According to the results of this model, while the high concentrations measured for 4-t-OP were not found to be associated with any of the household parameters, high levels of 4-n-NP and di-NPE were associated with the frequency of house cleaning, repairs made during the previous year, residential type, the number of occupants, flooring materials, and the purchase of new household items within the past year. This study provides a basis for prioritizing toxicology and exposure studies for EDCs and mixtures and may offer new tools for exposure assessment in health studies.