Determination and dietary risk assessment of neonicotinoid and insect growth regulators in honey

Aim: The aim of this study was to determine the presence, concentrations, dietary intake, and risk of residues of neonicotinoids (NEO) and insect growth regulators (IGR) in commercially available honey in South Africa.Methods: Sample preparation for honey was based on the “dilute and shoot” principle, followed by analysis using an internally validated ultra-high-performance liquid chromatographic coupled to tandem mass spectrometric method. Estimated daily intake and acute and chronic hazard quotients were determined to measure human exposure and health risk to NEO and IGR as well as the risk posed to honeybee.Results: NEO and IGR were detected in 50% and 21% of the 115 honey samples, respectively. The average concentration ranged 0.062-6.50 µgkg-1 and 0.479-1.644 µgkg-1 for NEO and IGR, respectively. While acetamiprid was the most detected (24.35%) NEO, imidacloprid presented the highest concentration (16.945 µg kg-1) in a sample. IGR co-occurred at variable concentrations with NEO in honey samples. The estimated daily intakes (EDI) of NEO and IGR ranged from 9.35 × 10-7 to 4.93 × 10-6 mg kg-1 bwd-1. The chronic hazard quotient (HQc) and acute hazard quotient (HQa) for NEO and IGR were considerably < 1, indicating negligible risk to human health and honeybee population.Conclusion: A UHPLC-MS/MS method was validated for the simultaneous determination of neonicotinoids and insect growth regulators in honey. Overall, the result of the present study confirms the widespread occurrence of NEO and IGR in honey consumed in South Africa. The EDIs, HQc, and HQa indicate that exposure to all target NEO and IGR via honey consumption constitutes negligible human health risk; however, the consequences of multiple routes of exposure to NEO and IGR cannot be overemphasized

Occurrence and distribution of tetrabromobisphenol A and its derivative in river sediments from Vaal River Catchment, South Africa

Brominated flame retardants (BFRs) compounds have been widely added in a number of products to reduce their flammability. In the present study, the concentrations and distribution of tetrabromobisphenol A (TBBPA) and its derivatives, i.e. tribromophenol dibromopropyl ether (TBPDBPE), tetrabromobisphenol A bis-dibromopropyl ether (TBBPA BDBPE), tetrabromobisphenol A bis-allyl ether (TBBPA BAE) were investigated in sediment samples collected from the Vaal River catchment, South Africa. The results showed that all these pollutants were detected in sediments with TBBPA BAE being the most abundant contaminant. The TBBPA BAE concentrations ranged from 3.5 to 44.4 ng/g (mean 16 ng/g) while the concentration ranged from not detected (nd) to 2.4 ng/g (mean 0.6 ng/g), nd - 21.0 ng/g (mean 6 ng/g) and nd - 2.0 ng/g (mean 0.2 ng/g) for TBPDBPE, TBBPA and TBBPA BDBPE; respectively. Higher concentrations of these pollutants were found in sampling sites receiving effluents of wastewater treatment works (WWTWs) treating some industrial wastewater suggesting effluents might play an important role in the contamination of BFRs in the environment. Negative correlation between TBBPA and TBBPA BAE was observed implying different sources or environmental fates between these pollutants. Overall, the results showed a need for further studies to be undertaken in investigating the presence, fate and sources of alternative halogenated flame retardants in the environment

Occurrence and distribution pattern of alkylphenol ethoxylates and brominated flame retardants in sediment samples from Vaal River, South Africa.

High environmental concentrations for alkylphenol ethoxylates (APEs) and brominated flame retardants (BFRs) have been observed near cities than in rural environment. This is due, in part, to sewage systems receiving effluents from many industrial processes along with domestic wastewater. While these classes of compounds are being phased out in most developed countries, there is still widespread use in low to middle income countries. To better understand the extent of APEs and BFRs contamination in the environment, this study reports on the concentration and distribution of APEs and BFRs in sediments samples collected from Vaal River, South Africa. Measurable concentrations of these contaminants were obtained using GC–MS after heptafluorobutyric derivatization. The concentrations range (ng g−1) for these pollutants were as follows: nd–46, 20–127, 24–38, 3–5, 14–28, 16–54 for octylphenol penta ethoxylates, nonylphenol ethoxylates (mono- di), nonylphenol penta ethoxylates, PBB101, PBDEs, and HBCD; respectively. The distribution observed in this study indicated higher levels of sediment contamination by APEs relative to BFRs. These results underline the need to further investigate the burden and risks associated with chemical contamination in developing countries

An integrated method for the simultaneous determination of alkylphenol ethoxylates and brominated flame retardants in sewage sludge samples by ultrasonic-assisted extraction, solid phase clean-up, and GC-MS analysis

Generally, a major route of alkylphenol ethoxylates (APEs) and brominated flame retardants (BFRs) to enter the environment is via the wastewater treatment works (WWTW) facilities. Consequently, the levels of APEs and BFRs in sewage sludges may give an indication of the general use and exposure of these compounds. The present study was aimed at an integrated method for the analysis and quantification of APEs and BFRs in sewage sludge from selected wastewater treatment plants. The optimization of the extraction procedure included variation of the amount of extracted biomass, the duration, temperature during sonication as well as type of extraction solvent. Chromatographic determinations of APEs and BFRs were carried out with gas chromatography equipped with mass spectrometry detector after derivatization with heptafluorobutyric anhydride (HFBA). The mean percentage recoveries ranged from 39% to 79% (n = 3) for sewage sludge after extracting 5 g biomass sludge with hexane: acetone (4:1) at 55 °C for 45 min in two cycles. The mean concentrations of APEs obtained ranged from < LOQ to 365 ng g− 1, < LOQ to 166 ng g− 1, < LOQ to 642 ng g− 1 while the concentration of BFRs obtained range from < LOQ- 17 ng g− 1, < LOQ to 163 ng g− 1, < LOQ to 14 ng g− 1 for sludge samples from Leeuwkuil, Rietspruit, and Sebokeng, respectively. All compounds, except for nonylphenol (NP), BDE47, and BDE154, were detected from the Rietspruit WWTW. The presence of these pollutants in Rietspruit WWTW may be attributed by the fact that this treatment plants treat wastewater from domestic as well industrial discharges from the surrounding area

Alkylphenols and alkylphenol ethoxylates in dust from homes, offices and computer laboratories: Implication for personal exposure via inadvertent dust ingestion

In the present study, the levels of alkylphenols (APs) and alkylphenol ethoxylates (APEs) in indoor dust of three different microenvironments were measured and daily intake via dust ingestion estimated. Alkylphenols and alkylphenol ethoxylates were extracted with the aid of sonication and analyzed by gas chromatography mass spectrometry after heptafluorobutyric anhydride derivatization. The concentration values of these pollutants ranged from 1918–10 935 ng g−1; 343–12 438 ng g−1 and 1122–15 324 ng g−1 in dust samples from homes, computer laboratories and offices, respectively. In all the microenvironment studied, di-NPE and mono-NPE were the most abundant isomers suggesting widespread use of NPE-based consumer products in the studied microenvironments. The daily exposure dose (DED) was estimated using min, mean and max concentrations of APs and APEs detected in respected microenvironments. The worst case scenario for the exposure of APEs was highest for toddlers at 146 ng kg−1 bw day−1 followed by teenagers at 11.3 ng kg−1 bw day−1 and adults at daily exposure of 8.53 ng kg−1 bw day−1. Though the daily exposure doses are low, there is a cause for concern as these surfactants are not regulated in many developing countries and their use may be increasing. Keywords: Alkylphenols, Alkylphenol ethoxylates, Concentrations, Indoor dust, Exposure assessmen