Pesticides, trace elements and pharmaceuticals in tea samples available in Belgian retail shops and the risk associated upon acute and chronic exposure

Development and validation of a ddPCR assay to detect and quantify tobacco DNA in smoke and smokeless tobacco and tobacco-free products

The last decade, smoke and smokeless products claiming to be tobacco-free, including herbal cigarettes and herbal shisha, became available on the European market and gained popularity. This study proposes a new digital droplet PCR (ddPCR) method, designed based on a previously developed real-time PCR (qPCR) method being currently used by the U.S. Food and Drug Administration (FDA) to specifically detect the presence of tobacco DNA in targeting a sequence from the Nicotiana tabacum nia-1 gene. To ensure a harmonized and reliable control by enforcement laboratories, both of these qPCR and ddPCR methods were then evaluated and validated for their compliance to an international standard. First, the performance of these PCR-based methods was successfully assessed as specific and sensitive, and in line with minimum performance requirements from international standard. Secondly, the transferability to external laboratory was confirmed for these PCR-based methods. Finally, the applicability of these PCR-based methods was demonstrated using 7 ground tobacco reference materials from the Tobacco Research Center (TRC) Toronto University as well as 6 commercial smokeless and tobacco-free smoke and smokeless products. Based on this study, the previously developed qPCR method was confirmed as complying with international standard, ensuring a efficient and harmonize use by enforcement laboratories for tobacco control on the European market. Moreover, this study proposed to enforcement laboratories the possibility to use a ddPCR method, enabling the simultaneous detection and absolute quantification of tobacco DNA as well as a limited impact of PCR inhibitors.

Trace elements in tea in Ouargla, Algeria and health risk assessment

Tea is one of the most common drinks, consumed for its pleasant flavour and several medicinal values. The present study aimed to determine the levels of trace elements in tea products marketed in the Saharan region of Ouargla, Algeria and to evaluate the health risks associated with its regular consumption in adults and infants. To this aim, 78 tea samples were analysed by Inductively Coupled Plasma - Mass Spectrometry. Tea samples appeared to be contaminated by lead (0.73 ± 0.08 µg g-1) and aluminium (0.22 ± 0.02 µg g-1). Cadmium, arsenic, mercury, cobalt, manganese, nickel, chromium, zinc and copper were also detected. General linear model analysis indicated that black tea samples were the most contaminated. Tea samples packed in tea bags were the most contaminated with arsenic, aluminium and manganese. The hazard index was 0.28 and 1.33 for adults and for infants, respectively, indicating adverse non-carcinogenic effects in infants.