Concentrations and health risk of polycyclic aromatic hydrocarbons in tea

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.

Polycyclic aromatic hydrocarbon (PAH) accumulation in selected medicinal plants: a mini review

The use of plant-based products in healthcare systems has experienced a tremendous rise leading to a substantial increase in global demand. However, the quality and effectiveness of such plant-based treatments are often affected due to contamination of various pollutants including polycyclic aromatic hydrocarbons (PAHs). Like other plants, medicinal plants also uptake and accumulate PAHs when exposed to a contaminated environment. The consumption of such medicinal plants and/or plant-based products causes negative effects on health rather than providing any therapeutic advantages. Unfortunately, research focusing on PAH accumulation in medicinal plants has received very limited attention. This review discusses a sizable number of literature regarding the concentration of sixteen priority PAH pollutants as recognised by the US Environmental Protection Agency (USEPA) in different medicinal plants. The review also highlights the risk assessment of cancer associated with some medicinal plants in terms of benzo[a]pyrene (BaP) equivalent concentrations.

Using QuEChERS and HPLC Method to Monitor the Background Concentration of Polycyclic Aromatic Hydrocarbons in Commercial Black Tea Leaves and Infusions in Taiwan

Tea is an integral part of Taiwanese culture and is a popular drink as it contains many beneficial compounds. However, during the processing of tea, polycyclic aromatic hydrocarbons (PAHs) may form. This study investigated the concentrations of PAH4 in different black tea leaves and tea infusions based on the origin of the tea. The samples were extracted using QuEChERS, while the content of PAH4 was analyzed by high performance liquid chromatography coupled to a fluorescence detector (HPLC-FLD). The content of PAH4 in the tea leaves ranged from 2.88 µg/kg to 218.2 µg/kg (dry weight), with the highest concentration being found in teas from Vietnam. The concentration of BaP ranged from ND to 47.92 µg/kg. The release of PAH4 from tea leaves to tea infusions was significantly low, with the highest transfer being 25.8%. In this study, all PAH4 compounds in commercial black tea leaves can be detected by QuEChERS extraction with a simple HPLC method.

Dietary Exposure and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Black Tea Consumed in Taiwan

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds found in many foods and drinks, and there have been some concerns over these compounds due to their carcinogenic nature. This study evaluated the concentrations of PAH4 (BaP, BaA, BbF, and CHR) in different black tea infusions and drinks based on the origin of the tea. The release of PAH4 from tea leaves to tea infusions was significantly low, with the highest transfer being 25.81%. The mean concentrations of BaP and PAH4 in tea infusions were used to conduct a risk assessment for the Taiwanese population, which showed that the 19-65 age group had the highest estimated intake of PAH4 and BaP among all age groups. These results, however, also showed margin of exposure (MOE) values well above the benchmark of 10,000. This indicated that PAH exposure from black tea consumption for the Taiwanese population constitutes a low-level health concern.

Assessment of High-temperature Refined Charcoal to Improve the Safety of Grilled Meat Through the Reduction of Carcinogenic PAHs

This study presents mitigation strategies for reducing carcinogenic polycyclic aromatic hydrocarbon (PAH) contamination levels in grilled meat using high-temperature refined charcoal (HTC) prepared by Iwate kiln, also known as high-quality charcoal. Four different types of HTC were investigated for their properties in conjunction with their potential to reduce PAHs in grilled meat, including high-temperature Eucalyptus charcoal (HTEC), Leucaena charcoal (HTLC), Acacia charcoal (HTAC), and bamboo charcoal (HTBC). The results showed that all HTCs had higher fixed carbon, higher heating value, and lower volatile compounds (83.07-87.81%, 7,306-7,765 Kcal/g, and 6.98-11.97%, respectively) than commercial low-temperature refined charcoal (LTC) (65.33%, 6,728 Kcal/g, and 22.22%, respectively). The current high fixed carbon content and heating value responded to the rising maximum temperature of charcoal up to 500-600°C, providing heat source stabilization to control the radiant energy exposure of charcoal during grilling, thereby shortening grilling time. The PAH16 value of the LTC-grilled sample (144.41 μg/kg) was significantly higher than that of the HTEC, HTLC, and HTAC-grilled samples (98.21, 80.75, and 79.56 μg/kg, respectively). However, PAH16 levels in the sample grilled with HTBC were unexpectedly high (265.75 μg/kg), and cooking loss was not significantly different between samples grilled with all charcoals. Overall, the findings indicated that using HTC prepared from Eucalyptus, Leucaena, and Acacia woods could reduce PAH contamination in grilled pork by up to 45%. However, more research is needed to determine the best preparation method for high-quality charcoal made from bamboo.

Environmental and human health risk assessments of polycyclic aromatic hydrocarbons in particulate matter in Nigeria

Polycyclic aromatic hydrocarbons (PAHs) are an important organic group in particulate matter which has attracted much attention among the scientific community in terms of health risk because of their carcinogenic, mutagenic, and ubiquitous nature in the environment. In this study, PAHs in particulate matter in Okitipupa were determined. Indoor and outdoor particle samples were sampled with the aid of SKC Air Check XR5000 high-volume gravimetric sampler, and analyzed using gas chromatography flame ionization detector (GC-FID). The results obtained showed that high molecular weight PAHs (5-ring, 6-ring PAHs) had higher mean concentration than low molecular weight PAHs (2-ring, 3-ring PAHs), in both indoor and outdoor particulate matter. Health risk assessments from exposure to these PAHs were also determined using toxicity equivalence quotient (TEQ), mutagenicity equivalence quotient (MEQ), incremental life cancer risk (ILCR), and hazard quotient (HQ). Dibenz(a,h)anthracene had the highest mean concentration across the sample location in both indoor and outdoor with values ranging from 33 to 31 and 90 to 93 µg/m³ respectively. The total mean concentration in outdoor PAHs ranged from 280 to 329 µg/m³, while total mean concentration in indoor PAHs ranged from 74 to 104 µg/m³. The incremental lifetime cancer risk in indoor ranged from 6.9 × 10^-7 to 1.2 × 10^-5, while the ILCR in outdoor ranged from 8.5 × 10^-6 to 1.0 × 10^-5. The hazard quotient in indoor ranged from 7.6 × 10^-5 to 2.2 × 10^-3, while the HQ in outdoor ranged from 10 × 10^-4 to 1.4 × 10^-3. These values are within the WHO permissible limit, and therefore underscores the danger associated with the inhalation of polycyclic aromatic hydrocarbons in Okitipupa.

Endothelial barrier dysfunction induced by anthracene and its nitrated or oxygenated derivatives at environmentally relevant levels

Polycyclic aromatic hydrocarbons (PAHs) are epidemiologically associated with cardiovascular diseases characterized by early key events involving in the disruption of endothelial barrier function. Whether PAHs can induce adverse cardiovascular outcome by directly destabilizing endothelial barrier function remains elusive. Herein, we investigated the effect of anthracene (ANT), 9-nitroanthracene (9-NANT), and 9,10-anthraquinone (9,10-AQ) on vascular endothelial barrier functions in human umbilical vein endothelial cells (HUVECs). The integrity of endothelial barrier in HUVECs was disturbed with a 1.15-1.42 fold increase in fluorescein leakage, and 21.8%-58.3% downregulated transendothelial electrical resistance. ANT, 9-NANT and 9,10-AQ promoted paracellular gap formation as revealed by transmission electron microscope. The disrupted cell junctions after 24 h exposure to ANT, 9-NANT and 9,10-AQ at 0.01 μM were indicated by the downregulated mRNA expression of vascular endothelial cadherin (VE-cadherin), zona occludens-1 (ZO-1) and occludin by 33.2%-71.4%, 19.1%-21.0%, and 31.9% respectively, and the downregulated protein expression of ZO-1 and occludin, and by the internalization of VE-cadherin. We demonstrated that ANT and its derivatives at environmentally relevant concentrations induced endothelial barrier dysfunction via the disruption of cell junctions, providing essential in vitro evidence on the association with their adverse cardiovascular outcomes.

Polycyclic Aromatic Hydrocarbons (PAHs) Sample Preparation and Analysis in Beverages: A Review

The monitoring of food contaminants is of interests to both food regulatory bodies and the consumers. This literature review covers polycyclic aromatic hydrocarbons (PAHs) with regard to their background, sources of exposures, and occurrence in food and environment as well as health hazards. Furthermore, analytical methods focusing on the analysis of PAHs in tea, coffee, milk, and alcoholic samples for the last 16 years are presented. Numerous experimental methods have been developed aiming to obtain better limits of detections (LODs) and percent recoveries as well as to reduce solvent consumption and laborious work. These include information such as the selected PAHs analyzed, food matrix of PAHs, methods of extraction, cleanup procedure, LOD, limits of quantitation (LOQ), and percent recovery. For the analysis of tea, coffee, milk, and alcoholic samples, a majority of the research papers focused on the 16 US Environmental Protection Agency PAHs, while PAH4, PAH8, and methylated PAHs were also of interests. Extraction methods range from the classic Soxhlet extraction and liquid–liquid extraction to newer methods such as QuEChERS, dispersive solid-phase microextraction, and magnetic solid-phase extraction. The cleanup methods involved mainly the use of column chromatography and SPE filled with either silica or Florisil adsorbents. Gas chromatography and liquid chromatography coupled with mass spectrometry or fluorescence detectors are the main analytical instruments used. A majority of the selected combined methods used are able to achieve LODs and percent recoveries in the ranges of 0.01–5 ug/kg and 70–110%, respectively, for the analysis of tea, coffee, milk, and alcoholic samples.

[Preparation of Fe3O4@BA-MOF magnetic solid-phase extraction material and its application to the detection of pesticide residues in tea]

Tea is one of the most popular beverages worldwide, and its quality is often affected by the excessive pesticide residues during production. During the detection of pesticide residues in tea by chromatography-mass spectrometry and other methods, a strong matrix effect attributed to tea polyphenols and pigments is observed, which seriously impacts the analysis results. In this study, Fe3O4 magnetic nanoparticles and boric acid-functionalized metal organic framework (BA-MOF) materials were combined to prepare a highly efficient adsorbent Fe3O4@BA-MOF for capturing tea polyphenols and pigments. An effective analysis method for pesticide residues in tea samples in combination with gas chromatography-mass spectrometry was established. The introduction of boronic acid ligands into the metal organic framework, as the recognition site of cis-diols, enhanced the polyphenol capture ability. Adsorption of the pigment in the matrix was achieved through π-π interactions between the MOF ligand and the pigment. This new material has significant advantages such as rapid magnetic separation, large surface area, and abundant functional sites. Fe3O4@BA-MOF was prepared by employing simple conditions and characterized by Fouriertransform infrared spectroscopy, scanning electron microscopy, and X-ray diffractometry to identify its functional groups and morphology. After investigating the adsorption effect of different doses of Fe3O4@BA-MOF adsorbents (5, 10, 30, 50, and 80 mg) on tea polyphenols, 50 mg of the adsorbent was added to the tea matrix and shaken thoroughly. The tea polyphenol content in the matrix solution was determined using an ultraviolet spectrophotometer. The polyphenols were reduced by 74.58% within 5 min. The effect of solution pH (2.0, 4.0, 6.0, and 7.0) on the adsorption efficiency was investigated, and pH 7.0 was chosen as the optimal condition. By adjusting the pH of the solution, Fe3O4@BA-MOF could be recycled, and it maintained the excellent adsorption performance after four cycles of use. The introduction of Fe3O4 magnetic nanoparticles led to rapid magnetic response characteristics during sample pretreatment and improved the pretreatment efficiency. In the actual application of tea pesticide detection, after Fe3O4@BA-MOF pretreatment, the average recovery rates of the ten pesticides were in the range of 75.8%-138.6%, and the RSD was in the range of 0.5%-18.7% (n=3). The Fe3O4@BA-MOF nanocomposite prepared by introducing the boric acid ligand into the MOF structure and incorporating Fe3O4 magnetic nanoparticles could specifically adsorb the tea polyphenol matrix. When applied to the detection of pesticide residues in tea, it purifies the matrix and improves the detection efficiency, thus being suitable for the detection and analysis of pesticides in tea.

Risk assessment and ecotoxicological diagnosis of soil from a chemical industry park in Nanjing, China

Soil pollution due to the activities of industrial parks, is becoming an increasingly serious issue, particularly throughout China. Therefore, it is essential to explore the soil pollution characteristics and its ecotoxicological effects on model species, such as higher plant species, in typical industrial areas. In this study, concentrations of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were examined in the soil collected from 10 sampling sites at a chemical industry park in Nanjing, China. The pollution index was used to assess the heavy metal pollution level of soils, while the hazard index (HI) and carcinogenic risk index (RI) were calculated to assess the human health risk of soil PAHs. In addition, wheat (Triticum aestivum L.) was used as the model species to evaluate the ecotoxicological effects of polluted soil in pot experiments. Results showed that the content of heavy metals and PAHs varied greatly in soil samples, among which the heavy metal pollution at S1, S2 and S3 was the most serious. The health risk assessment of PAHs indicated that non-carcinogenic and carcinogenic values for all soil samples were below the threshold levels. Statistical analysis of the correlation between contaminated soil and toxic effects in wheat found that the significance values of regression equations were all less than 0.05 for chlorophyll content, peroxidase (POD) and amylase (AMS) activity. This indicates that the chlorophyll content, POD and AMS activity in wheat leaves could be suitable biomarkers for evaluation of the combined toxicity of multiple pollutants. This study provides a reference for future research on the risk assessment of soil containing multiple pollutants from industrial chemical parks.

Effects of manufacturing procedures and preparation conditions on European Union priority polycyclic aromatic hydrocarbons in Oolong tea samples

The study evaluated the changes in polycyclic aromatic hydrocarbons (PAHs) of Oolong tea samples at each heat treatment stage of the manufacturing process, different post-treatment methods and different brewing conditions. The content of PAHs in the tea leaves was significantly increased during stir fixation (280 °C for 8 min) stage of the manufacturing process. In the subsequent heat treatment process, the PAHs content did not change much until the Oolong tea product (primary) was further roasted. The level of PAHs increased with the roasting time. Charcoal roasting resulted in higher PAHs content in the product compared with electric roasting. Higher brewing temperature caused higher level of PAHs released into the tea infusion. The level of released PAHs decreased with the increase of the number of tea brewing (the total released PAHs was about 4%). The risk assessment results for PAHs in the tea infusions showed a low level of health concern.

Magnetic hydrophobic solids prepared from Pickering emulsions for the extraction of polycyclic aromatic hydrocarbons from chamomile tea

Two types of magnetic hydrophobic solids were prepared by Pickering emulsion photopolymerization using polystyrene-modified magnetic nanoparticles (PS-MNPs) as emulsion stabilizers. Additionally, PS-MNPs provided magnetic character to the final solids. W/O Pickering emulsions were produced with high amounts of oily phase (above 50 wt%), while O/W Pickering emulsions were formed with higher amounts of aqueous phase (above 60 wt%). These two types of emulsions led to two kind of solids with very different structures despite being formed by the same components. In this way, W/O Pickering emulsions produced monolithic solids, while O/W Pickering emulsions formed magnetic microparticles. Multi-walled carbon nanotubes (MWCNTs) were also added to the emulsions to provide higher hydrophobic character to the final solids. The structure and morphology of both magnetic solids containing the MWCNTs was characterized by scanning electron microscopy (SEM). Finally, their extraction efficiency was evaluated using polycyclic aromatic hydrocarbons (PAHs) as target analytes, both qualitatively (visually by the fluorescence emitted before and after the extraction) and quantitatively (using gas chromatography coupled to mass spectrometry). Therefore, the LODs ranged from 1 to 4 μg L^-1 and the LOQs were between 3 and 12 μg L^-1. The reproducibility of the extraction procedure with different batches of emulsions was acceptable with RSD values <13%. Finally, a recovery study was carried out in complex matrices such as chamomile tea, obtaining excellent recovery values which ranged from 99 to 108%.

Air-assisted liquid-liquid microextraction based on the solidification of floating deep eutectic solvents for the simultaneous determination of bisphenols and polycyclic aromatic hydrocarbons in tea infusions via HPLC

Deep eutectic solvents (DESs) are a new class of green "designer solvent"; its physicochemical properties can be easily tuned by adjusting DES' constituents, chemical ratio and water content. In this study, three hydrophobic DESs with low viscosity, low density, and melting points close to room temperature were designed and synthesized. Based on these DESs, an air-assisted liquid-liquid microextraction technique was developed based on the solidification of floating DESs for the simultaneous determination of bisphenols and polycyclic aromatic hydrocarbons (PAHs) via HPLC. The microextraction parameters were optimized via the Plackett-Burman design and response surface methodologies. The method shows satisfactory linearity (R² ≥ 0.9928), a low limit of detection (0.16-0.75 μg L^-1) and satisfactory precision (≤2.3%), and was successfully applied for the simultaneous determination of bisphenols and PAHs from tea infusions with satisfactory recoveries (82.0-116.6%). This method is simple, rapid, economical, environmentally compatible, dispersive solvent-frees and centrifugation-free, and has promising applications in food safety.

Polycyclic aromatic hydrocarbons (PAHs) in dry tea leaves and tea infusions in Vietnam: contamination levels and dietary risk assessment

The total mean ∑[Formula: see text] in samples were from 75.3 to 387.0 ng/g dry weight (d.w) and showed high value in black dry tea, followed by herbal, oolong, and green tea. The mean ∑[Formula: see text] (a combination of benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene) values were 54.3 ng/g, 16.4 ng/g, 14.2 ng/g, and 6.6 ng/g for black, herbal, green, and oolong teas, respectively. Concentration for benzo[a]pyrene (BaP) was from 0.4 to 35.8 ng/g, and the BaP equivalent concentration values ranged from 0.3 to 48.1 ng/g. There was only 1 black tea sample that BaP concentration exceeded the maximum level according to European Union (EU) standards. Tea samples marketed in Vietnam showed insignificant difference with the samples from other origins by same analytical method. Black teas showed high PAHs contents in dry tea samples but the released percentage of sum of PAHs from tea-to-tea infusion was lower than that in other tea type samples. The released percentages of PAH4 from tea-to-tea infusion were 40.7, 15.4, and 1.9 for green, herbal, and black tea. High temperature in black tea manufacturing processes might reduce essential oil content in tea that might effect on the PAHs partially release into the infusion. Indeed, based on EU regulations, we may conclude that tea consumers are safe in risk of exposure to PAHs obtained from teas.

Polycyclic aromatic hydrocarbons as a potential source of carcinogenicity of mate

Drinking mate, an infusion of the herb ilex paraguariensis, is very common in several South American countries, and has been associated with an increased risk of esophageal cancer. This increased risk may be attributed to drinking mate very hot, or to mate's potentially carcinogenic contaminants, such as polycyclic aromatic hydrocarbons (PAHs). Mate leaves are often dried via smoking, and therefore commercial samples may have high amounts of PAHs. We found 10 original articles that had measured PAHs in commercial dry samples, and nearly all found very high mass fractions. Most studies found benzo[a]pyrene mass fractions to be over 25 ng/g, and some found levels up to 600 ng/g. However, carcinogenic PAHs are often hydrophobic, and may not readily transfer into infusions. Seven articles studied transfer rates, and these rates varied from 1 to 50%, depending on the methods employed. Further careful studies of transfer rates in situations that mimic real life drinking of mate are recommended. Also, further studies of biological indicators of PAH exposure, particularly in randomized experiments, and analyzing DNA from tumor samples of mate drinkers are recommended.

Simultaneous Determination of 18 Polycyclic Aromatic Hydrocarbons in Daily Foods (Hanoi Metropolitan Area) by Gas Chromatography⁻Tandem Mass Spectrometry

Polycyclic aromatic hydrocarbons (PAHs)-a large group of organic compounds-are extremely hazardous to human health. In this study, the 198 samples from six groups of daily food products in the Hanoi metropolitan area were collected and prepared by the QuEChERS sample treatment technique. The detection and identification of PAHs were obtained by gas chromatography⁻tandem mass spectrometry (GC⁻MS/MS) determination. The results demonstrated that the recovery of PAH compounds ranged approximately between 71% and 110% when the solvent evaporation condition was optimized using the nitrogen gas at a low temperature (1 °C). The in-house method was validated in terms of linearity, extractive condition, repeatability, recovery, limit of detection (LOD), and limit of quantification (LOQ). The ranges of average PAH levels were 9.3⁻9.6 µg/kg (for instant noodles), 0.22⁻2.48 µg/kg (for cakes) 0.91⁻4.83 µg/kg (dried vegetables), 5.14⁻23.32 µg/kg (teas), 4.82⁻24.35 µg/kg (coffees), and 1.43⁻25.2 µg/kg (grilled meats). The results indicated that the total concentrations of residual PAHs and benzo(a)pyrene in the instant noodles and grilled meat samples surpassed the maximum limits tolerated by the European Commission (35 µg/kg and 5 µg/kg, respectively) in many investigated samples.

Determination and risk characterization of polycyclic aromatic hydrocarbons of tea by using the Margin of Exposure (MOE) approach

Tea is one of the most frequently consumed drinks due to its favourite taste and the health benefit. Tea is produced by several processes and drying is very important step to develop the flavour and destroys the enzymes in tea. However, during drying tea, polycyclic aromatic hydrocarbons some of which are carcinogen and genotoxin are naturally produced. The risk of PAHs by drinking tea was characterized by determining contents of 4 PAHs in tea. 4 PAHs including Benz(a)anthracene (BaA), Chrysene (CHR), Benzo(b)fluoranthene (BbF) and Benzo(a)pyrene (BaP) were investigated by GC-MS in total 468 tea products, which were contaminated up to 4.63 ng g-1. Mate tea was the most highly contaminated by BaA, CHR, BbF and BaP and followed by Solomon's seal and Chrysanthemum. The Margin of Exposures calculated by the concentration of BaA, CHR, BbF and BaP and consumption amount of tea were higher than 10,000, and the risk of PAHs in tea were low concern to public health.

Body mass index trajectories during the first year of life and their determining factors

OBJECTIVE

The purpose of this study was to examine the trajectories of body mass index (BMI) in the first year of life and their determining factors.

METHODS

We used data from the Infant Feeding Practices Survey II restricted to children with 2 or more time points of BMI data during follow-up visits within the first year of life (n = 2320). Latent class growth analysis was used to identify distinct BMI trajectories. Using multinomial logistic regression, we examined the prenatal and early life determinants of the identified trajectories.

RESULTS

Three BMI trajectories were identified during the first year of life: "low-stable" (81.6%), "high-stable" (15.6%), and "rising" (2.8%) trajectories. Boys, preterm infants, infants born to overweight mothers, Hispanic mothers, non-Hispanic Black mothers, and mothers who smoked during pregnancy were significantly more likely to have high-stable versus low-stable trajectories. Infants born to non-Hispanic Black mothers were more likely to have a rising versus a low-stable trajectory. Household income ≥350% of the federal poverty level and full adherence to the guidelines of the American Academy of Pediatrics for both breastfeeding exclusivity and duration reduced the likelihood of infants being in the rising versus the low-stable trajectory.

CONCLUSION

Distinct BMI trajectories were evident as early as infancy. The predictors of these trajectories offer information about high-risk groups, and important and preventable prenatal and postnatal risk factors for future intervention programs.

Polycyclic aromatic hydrocarbons in teas using QuEChERS and HPLC-FLD

Polycyclic aromatic hydrocarbons (PAHs) are food-processing contaminants considered to be carcinogenic and genotoxic. Due to its drying process stage, teas may be contaminated with PAHs. The aim of the study was to validate an analytical method involving QuEChERS and HPLC-FLD for the determination of PAH4 in teas and evaluate the contamination levels in 10 different types of teas from Brazil. Recoveries varied from 54% to 99% and relative standard deviations from 1% to 21%. Limits of detection and quantification were from 0.03 to 0.3 µg/kg and 0.1 to 0.5 µg/kg, respectively. Mate tea presented the highest PAH levels, with PAH4 varying from 194 to 1795 µg/kg; followed by black (1.8-186 µg/kg), white (24-119 µg/kg), and green teas (3.1-92 µg/kg). Teas with lowest PAH4 were strawberry, lemongrass, peppermint, and boldo. Only trace levels of PAHs were detected in tea infusions, so apparently it would not affect PAH intake by Brazilian population.

Aluminum and Heavy Metal Accumulation in Tea Leaves: An Interplay of Environmental and Plant Factors and an Assessment of Exposure Risks to Consumers

Environmental and plant factors (soil condition, variety, season, and maturity) and exposure risks of aluminum (Al), manganese (Mn), lead (Pb), cadmium (Cd), and copper (Cu) in tea leaves were investigated. The concentrations of these metals in tea leaves could not be predicted by their total concentrations in the soil. During any one season, there were differences in Al, Mn, and Cd levels between tea varieties. Seasonally, autumn tea and/or summer tea had far higher levels of Al, Mn, Pb, and Cd than did spring tea. Tea leaf maturity positively correlated with the concentrations of Al, Mn, Pb, and Cd, but negatively with Cu. The calculated average daily intake doses (mg/ [kg•d]) for these metal elements were 0.14 (Al), 0.11 (Mn), 2.70 × 10^-3 (Cu), 2.80 × 10^-4 (Pb), and 2.88 × 10^-6 (Cd). The hazard quotient values of each metal were all significantly lower than risk level (=1), suggesting that, for the general population, consumption of tea does not result in the intake of excessive amounts of Al, Mn, Pb, Cd, or Cu. This study identified the factors that can be monitored in the field to decrease consumer exposure to Al and Mn through tea consumption.

PRACTICAL APPLICATION

Environmental and plant factors influence aluminum and heavy metal accumulation in tea leaves. Consumers of tea are not ingesting excessive Al, Mn, Pb, Cd, or Cu. Trackable factors were identified to manage exposure levels.

Comparative oesophageal cancer risk assessment of hot beverage consumption (coffee, mate and tea): the margin of exposure of PAH vs very hot temperatures

Background

Consumption of very hot (> 65 °C) beverages is probably associated with increased risk of oesophageal cancer. First associations were reported for yerba mate and it was initially believed that high content of polycyclic aromatic hydrocarbons (PAH) might explain the risk. Later research on other beverage groups such as tea and coffee, which are also consumed very hot, found associations with increased risk of oesophageal cancer as well. The risk may therefore not be inherent in any compound contained in mate, but due to temperature. The aim of this study was to quantitatively assess the risk of PAH in comparison with the risk of the temperature effect using the margin of exposure (MOE) methodology.

Methods

The human dietary benzo[a]pyrene (BaP) and PAH4 (sum of benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene) exposure through consumption of coffee, mate, and tea was estimated. The oesophageal cancer risk assessment for both PAH and temperature was conducted using the MOE approach.

Results

Considering differences in the transfer of the PAH from the leaves of mate and tea or from the ground coffee to the infusion, and considering the different preparation methods, exposures may vary considerably. The average individual exposure in μg/kg bw/day arising from consumption of 1 cup (0.2 L) of infusion was highest for mate (2.85E-04 BaP and 7.22E-04 PAH4). The average per capita exposure in μg/kg bw/day was as follows: coffee (4.21E-04 BaP, 4.15E-03 PAH4), mate (4.26E-03 BaP, 2.45E-02 PAH4), and tea (8.03E-04 BaP, 4.98E-03 PAH4). For all individual and population-based exposure scenarios, the average MOE for BaP and PAH4 was > 100,000 independent of beverage type. MOE values in this magnitude are considered as a very low risk. On the contrary, the MOE for the temperature effect was estimated as < 1 for very hot drinking temperatures, corroborating epidemiological observations about a probable oesophageal cancer risk caused by this behaviour.

Conclusions

The temperature effect but not PAH exposure may pose an oesophageal cancer risk. Consumer education on risks associated with consumption of ‘very hot’ beverages and policy measures to threshold serving temperatures should be discussed.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4060-z) contains supplementary material, which is available to authorized users.