Occurrence of synthetic phenolic antioxidants and transformation products in urban and rural indoor dust

Abstract

In this study, seven synthetic phenolic antioxidant (SPA) analogues were positively found in urban and rural indoor dust samples collected from Shandong province in China, among which the novel 2,4,6-tri-tert-butylphenol (AO 246), 2,6-di-tert-butyl-4-sec-butylphenol (DTBSBP), 2,4-di-tert-butylphenol (DBP) and 4,4'-butylidenebis (2-(1,1-dimethylethyl)-5- methyl-phenol) (AO 44B25) analogues accounted for 29% of total SPA concentrations (∑SPAs). Urban dust showed significantly higher ∑SPA levels (range: 1.56e3 - 2.03e4 ng/g) compared with those in rural indoor dust (668-4.39e3 ng/g, p < 0.05). 2,6-Di-tert-butyl-4-methylphenol (BHT) was the dominate analogue in the urban indoor dust, which constituted of 74% in ΣSPAs. While, varied composition profiles of SPAs were noticed in rural indoor dust, for instance, AO 246 (46%) and BHT (43%) had similar contributions to ∑SPAs. Three BHT transformation products (TPs) were also detected in most of the urban and rural dust samples (>97%), with individual residue level in the same order: 2,6-di-tert-butyl-1,4-benzoquinone (BHT-Q) > 2,6-di-tert-butyl-4-hydroxy- 4-methyl-2,5-cyclo-hexadienone (BHT-quinol) > 3,5-di-tert-butyl-4-hydroxybenzal-dehyde (BHT-CHO). Geometric mean values of total TP concentrations were 555 ng/g and 131 ng/g for urban and rural indoor dust samples, respectively. A preliminary estimated daily intake calculation at dust ingestion scenario suggested additional concerns might be paid to simultaneous exposure of several SPA analogues and TPs besides current focus on BHT exposure risks.

Synthetic Phenolic Antioxidants: A Review of Environmental Occurrence, Fate, Human Exposure, and Toxicity

“…Liu et al detected seven SPAs in indoor dust collected in urban and rural indoor environments in Shandong Province, China, with ∑SPAs falling between 0.67 μg/g and 20.3 μg/g (median: 2.31 μg/g). 19 The SPA concentrations in urban indoor dust (median: 2.56 μg/g) were around 30% higher than those in rural indoor dust (median: 1.89 μg/g). Similarly to what was found by Wang et al, BHT (median: 1.59 μg/g) was the dominant congener, contributing 66% to ∑SPAs.…”

“…Notably, along with their parent chemical, several transformation products of BHT (BHT-OH, BHT-CHO, BHT-COOH, BHT-quinol, and BHT-Q) were also detected in indoor dust with sum concentrations (median) ranging from 0.02 μg/g to 3.02 μg/g. 13,19,42,43 3.2. Outdoor Environment.…”

“…Generally, the total SPA concentrations (∑SPAs) in indoor dust collected in developed countries such as the United States (median: 8.17 μg/g), Japan (median: 20.7 μg/g), and South Korea (median: 11.5 μg/g) were higher than those in indoor dust collected in developing countries such as Vietnam (median: 0.31 μg/g), Columbia (median: 0.83 μg/g), and India (median: 1.62 μg/g). Liu et al detected seven SPAs in indoor dust collected in urban and rural indoor environments in Shandong Province, China, with ∑SPAs falling between 0.67 μg/g and 20.3 μg/g (median: 2.31 μg/g) . The SPA concentrations in urban indoor dust (median: 2.56 μg/g) were around 30% higher than those in rural indoor dust (median: 1.89 μg/g).…”

“…18 SPAs are additives that are not chemically bonded to the substrates. Due to the wide production and use of SPAs, many SPAs have been detected in environmental matrices such as dust, 19 sea sediment, 20 and river waters. 21 SPAs have also been detected in wild-captured organisms such as mollusks and shrimps.…”

“…SPAs are additives that are not chemically bonded to the substrates. Due to the wide production and use of SPAs, many SPAs have been detected in environmental matrices such as dust, sea sediment, and river waters . SPAs have also been detected in wild-captured organisms such as mollusks and shrimps. , Some SPAs have been detected in human serum and urine samples. , In most of these studies, BHT was the dominant congener detected, with several other congeners, such as 2,4-di- tert -butyl-phenol (DBP), also present at significant concentrations .…”