Dietary exposure and risk characterisation of multiple chemical contaminants in rye‐wheat bread marketed in Poland

Abstract

The aim of this work was to collect occurrence data on chemical contaminants in rye‐wheat bread marketed in Poland and subsequently estimate the risk due to dietary exposure to those chemicals for different population age groups in Poland. The choice of the food matrix has been driven by the fact that bread is an important component of the diet of Poles. Therefore, the collection of data on this staple food might be of interest form a public health perspective. The analytes under investigation belong to different categories: process contaminants (acrylamide), mycotoxins (deoxynivalenol, deoxynivalenol‐3‐glucoside, nivalenol and nivalenol‐3‐glucoside) and environmental contaminants (aluminium, arsenic, cadmium, chromium, lead and nickel). The activities presented in this technical report have been carried out in the frame of the European Food Risk Assessment (EU‐FORA) Fellowship Programme. The objective of the fellowship is to provide middle‐early career scientists with new skills and knowledge on food risk assessment. This goal is pursued through a hands‐on experience in a competent organisation active in fields within EFSA's mission. In this case, the work programme has been implemented at the Department of Food Safety and Chemical Analysis of the State Research Institute of Agriculture and Food Biotechnology Prof. Wacław Dąbrowski (IBPRS‐PIB), located in Warsaw, Poland. A significant part of the research work consisted in the implementation of different analytical techniques to collect occurrence data that were subsequently combined with consumption data retrieved from the EFSA Comprehensive European Food Consumption Database to assess the exposure and characterise the risk. Finally, an attempt has been made to identify uncertainties and evaluate their impact on results.

1. Introduction

The activities described in this report have been carried out in the frame of the European Food Risk Assessment (EU‐FORA) Fellowship Programme cycle 2021–2022. The main purpose of this initiative, established by the European Food Safety Authority (EFSA) in 2016, is to increase the pool of food safety experts and strengthen the food risk assessment network across Europe with the ultimate objective of building a common culture for risk assessment in the European Union. This initiative fulfils Article 23 (b) of EFSA's Founding Regulation (Reg. EC no 178/2002) that appoints EFSA to be responsible for promoting and coordinating the development of uniform risk assessment methodologies in the fields falling within its mission. During the 12‐month EU‐FORA fellowship, participants are entitled to carry out risk assessment activities with a learning‐by‐doing approach at the premises of one of the competent organisations adopted by EFSA Management Board according to Article 36 of Regulation (EC) no 178/2002. The hands‐on experience was complemented by 7 weeks of training divided in 3 weeks of induction training and four specific 1‐week modules held throughout the 12‐month placement period.

2. Description of work programme

2.1. Aims

The main goal of the project was to estimate the risk to Polish population related to the dietary exposure to chemical contaminants with special focus on the consumption of rye‐wheat bread. Contamination levels and dietary habits are constantly changing. On this regard, the work was conducted with the purposes of contributing to a better understanding and to the monitoring of the adequacy and safety of the diet of Poles. Gathering up‐to‐date data is key to reach this intent. The regular collection of accurate and reliable data is a prerequisite for informed risk assessment and risk management.

2.2. Activities/Methods

Food matrix and sampling strategy

Bread is a staple food. It is consumed every day by many people, from children to elderly, in many countries. For this reason, investigating the risks associated to the consumption of this product could be interesting from a public health perspective. Since the most common type of bread in Poland is the one produced with rye‐wheat flour (Mojska et al., 2010), the research has been focused on the category ‘Rye‐wheat bread and rolls, refined flour’. The 51 loaves composing the sample subject to the study have been randomly collected in different popular supermarkets in Warsaw, Poland. The implementation of this non‐targeted sampling strategy at the market place aimed to reflect Poles' consumption habits and to estimate the contaminants' concentration as close to the time and real conditions of consumption as possible. This matrix is labelled with the code A005N and described in the EFSA's food classification and description system MTX (FoodEx2 Matrix) catalogue version 13.1. as ‘any type of bread and rolls containing considerable proportions of wheat and rye refined flours (i.e. containing very little or no bran). The part consumed/analysed is by default the whole or a portion of it representing the observed heterogeneity’. A representative portion of each loaf has been lyophilised, and grinded to a powder. This ensured prolonged storage stability thanks to the removal of water. Slices were weighted before and after lyophilisation to allow the expression of results as fresh product (as it is actually consumed).

Bread consumption

Since 1989, Poland experienced profound political and economic amendments. The switch from a centrally planned to the market economy system leaded to considerable changes in the lifestyle of Poles. Therefore, assessing the nutritional situation of the population became of great interest. Given the lack of representative, countrywide, individual dietary surveys in Poland, the government requested technical assistance from the United Nations Food and Agriculture Organization (FAO) to enrich the existing nutrition information system. This leaded to the implementation of a project that examined the diets and anthropometric characteristics of a nationally representative sample of Polish households surveyed from September to November 2000. Data have been collected through household budget surveys (HBS) and individual nutrition surveys (INS) based on single 24‐h recall with the support of an album of colour photographs representing 201 food items, dishes, soft drinks and alcoholic beverages commonly consumed in Poland in three different portion sizes. Body weight have been measured using digital electronic personal weighing scales. Individuals were aged between 0 and 96 years. It is worth noticing that food eaten away from home was excluded from the analysis to facilitate the comparison between the two methodologies. The results obtained from the two survey methodologies showed poor agreement between purchasing and consumption of bread and rolls. Specifically, the acquisition was 24–30% greater than consumption (Szponar et al., 2001, 2003; Sekula et al., 2004). This shows that a proportion of purchased bread and rolls is likely to be wasted (Sekula et al., 2004). When intra‐individual variation is small relative to interindividual variation, population intakes can be reliably estimated with consumption data from a smaller number of days than should be obtained if both types of variation are large (Petersen, 2000). Therefore, 24‐h recall surveys can be considered quite accurate for the assessment of dietary exposure to contaminants present in commonly consumed products such as bread. For these reasons, the current risk assessment has been based on the data obtained with this survey. The results of this 24‐h recall are present in the EFSA Comprehensive European Food Consumption Database (code: IZZ FAO 2000).

Acrylamide

Acrylamide (AA) is a low molecular weight, highly water soluble, organic compound. It forms in foods containing asparagine and reducing sugars prepared at temperatures above 120°C and low moisture. Therefore, it is known to be present in numerous baked or fried carbohydrate‐rich foods, including French fries, potato crisps, breads, biscuits and coffee. This chemical has also been found in cigarette smoke. Different types of grains have shown different levels of asparagine. Typically, asparagine levels are the highest in rye and in descending order lower in oats, wheat, maize and with the lowest levels in rice (Reg. EC no 2158/2017). The EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) listed ‘Soft bread’ among the main contributors to the total dietary exposure to AA of toddlers, other children, adolescents, adults, elderly and very elderly (EFSA, 2015). Moreover, scientists of the Polish National Food and Nutrition Institute – State Research Institute (NIZP PZH – PIB), identified bread as the main food source of AA in the Polish diet contributing to the 31% of the total dietary exposure to AA of 1–6 age children and to the 49% exposure of the adult population. According to the authors, this is due to the frequency and amount of consumption of this staple more than its contamination level (Mojska et al., 2010). Benchmark levels for the presence of AA in foodstuffs have been set in Regulation (EU) no 2158/2017. In case of soft bread other than wheat‐based bread, the benchmark level is 100 μg/kg.

Occurrence

The levels of AA in the analytical samples were determined with the use of a gas chromatograph coupled to single quadrupole mass spectrometer. The analytical method has been implemented adding an internal standard solution to the analytical samples and using solid‐phase extraction (SPE) cartridges to extract the analyte from the matrix. The method was based on an in‐house validated procedure performed with few adjustments (Roszko et al., 2019).

Results show that the mean (40.73 μg/kg) is bigger than the median (38.10 μg/kg) and skewness is positive (1.10). Other values of interest are Standard Deviation (17.11 μg/kg) and maximum value (94.67 μg/kg). Considering those values, it is assumed that data follow a log‐normal distribution. This is in line with what stated in literature: in the field of food contaminants, the log‐normality of the distribution is generally assumed (Kroes et al., 2002). Since the log of the measurements is normally distributed, it is more accurate to work with the logarithms of the measurements (Miller and Miller, 2010) and calculate the geometric mean (37.60 μg/kg) and its 95% confidence interval (lower bound (LB) 33.58 μg/kg and upper bound (UB) 42.10 μg/kg).

Exposure assessment

Chronic exposure to AA was estimated for each population group by multiplying the 95th percentile consumption data (g/kg bw per day) with the upper level of the 95% confidence interval of the geometric mean (0.042 μg/g). Assuming that that bread contributes for 31% of the total dietary exposure to AA in 1–6 age children, for 40% in children and adolescents (7–8 years) and for 49% in adults from 19 to 96 (Mojska et al., 2010), the total dietary exposure to AA for each age group have been calculated.

Risk characterisation

The EFSA CONTAM Panel considered inappropriate to establish a tolerable daily intake (TDI) since AA is of concern with respect to genotoxicity. Therefore, the reference point for risk characterisation of the non‐neoplastic effects of AA derived by the CONTAM Panel is the BMDL₁₀ value of 0.43 mg/kg bw per day and the one for risk characterisation of the neoplastic effects is BMDL₁₀ of 0.17 mg/kg bw per day. Both BMDL₁₀ values were selected based on experimental animal evidence since data from human studies were inadequate for dose–response assessment. Usually, for non‐genotoxic compounds, a margin of exposure (MOE) of 100 is considered sufficient to conclude that there is no health concern. This MOE covers uncertainties and variability with regard to differences between experimental animals and humans (factor 4 × 2.5 = 10), and within the human population (factor 3.2 × 3.2 = 10). However, the CONTAM Panel considered appropriate to use a compound‐specific adjustment factor for risk characterisation of the non‐neoplastic effects of AA. This results in an adjusted MOE of 125. The CONTAM Panel deemed correct the use of the MOE approach for compounds that are both genotoxic and carcinogenic for risk characterisation of the neoplastic effects. In this case, an MOE of 10,000 or higher, based on a BMDL₁₀ from an animal study, would be of low concern from a public health point of view (EFSA, 2015).

MOE values for non‐neoplastic and neoplastic effects related to the estimated total dietary AA were calculated for the 95th percentile exposure for each population group. Results show that MOEs for non‐neoplastic effects across age groups are not of concern (MOE ≥ 125). Whereas, MOEs for neoplastic effects are of concern from a public health point of view across all age groups (MOE < 10,000). It is worth noticing that MOEs for neoplastic effects across all age groups are substantially below the safe value even when considering only bread consumption. These results are in line with what stated by EFSA in the last Scientific Opinion on AA in food related to the European population (EFSA, 2015) and in a previous study on risk evaluation of AA intake with bread in Poland (Roszko et al., 2019).

Mycotoxins

Mycotoxins are secondary fungal metabolites, toxic to human and animals. Fungi producing mycotoxins can infect living plants in the field and/or colonise crops during storage. Deoxynivalenol (DON) and nivalenol (NIV) are produced by various species of Fusarium genus. Plants use detoxification mechanisms as a defensive strategy against pathogens. This process leads to the transformation of the chemical structure of mycotoxins into modified forms such as deoxynivalenol‐3‐glucoside (DON‐3‐glucoside) and nivalenol‐3‐glucoside (NIV‐3‐glucoside). Those transformed molecules are called masked mycotoxins (Berthiller et al., 2013; Ksieniewicz‐Woźniak et al., 2019). All these compounds belong to the chemical group of type B trichothecenes. DON is chemically stable and to some extent resistant to thermal processing. As a result, it is found in cereal‐based foods such as bread. EFSA assessed the risks to human and animal health related to the presence of NIV, DON and its modified forms in food and feed. In both cases, grains and grain‐based foods were the main contributors as dietary sources to the exposure for humans (EFSA, 2013, 2017). The maximum level (ML) of DON in bread have been set to 500 μg/kg in Regulation (EC) No 1881/2006.

Occurrence

The analytical method used in this study was aimed at determining the co‐occurrence of DON, DON‐3‐glucoside, NIV and NIV‐3‐glucoside. Considering their chemical similarities, the use of immunoaffinity columns containing antibodies specific both to DON and NIV facilitated the simultaneous extraction of all the compounds from the matrix. After extraction and clean‐up steps, analytes were determined with high‐performance liquid chromatography (HPLC) coupled to UV detector. The results of the analysis show that NIV, NIV‐3‐glucoside and DON‐3‐glucoside were not found and DON have been detected in 48 out of 51 loaves analysed. Descriptive statistics of DON's analytical data show that the mean (49.50 μg/kg) is bigger than the median (37.63 μg/kg) and skewness is positive (0.98). Other values of interest are Standard Deviation (26.84 μg/kg) and maximum value (109.11 μg/kg). Considering those values, it is assumed that data follow a log‐normal distribution. In this case, it is more accurate to work with the logarithms of the measurements (Miller and Miller, 2010) and calculate the geometric mean (43.46 μg/kg) and its 95% confidence interval (LB 37.53 μg/kg and UB 50.32 μg/kg).

Exposure assessment

Chronic exposure to DON was estimated for each population group by multiplying the 95th percentile consumption data (g/kg bw per day) with the upper level of the 95% confidence interval of the geometric mean (0.050 μg/g). According to the EFSA opinion, the category ‘bread and rolls’ can be responsible for up to 50% of the total dietary exposure in the population groups from infants to adults and exceed 50% for elderly and very elderly (EFSA, 2017). In case of elderly and very elderly a contribution of 65% has been assumed. Based on these considerations and on the occurrence data obtained from the analysis, the total dietary chronic exposure to DON has been calculated for each population group.

Risk characterisation

The CONTAM Panel established a group‐TDI of 1 μg/kg bw per day for the sum of DON and its modified forms. Moreover, a group acute reference dose (ARfD) of 8 μg/kg bw per eating occasion has been established based on human data on vomiting and gastrointestinal effects, collected in a number of epidemiological studies on the outbreaks of acute mycotoxicosis in Asia. According to the results of this work, the estimate of chronic dietary exposure to DON for other children is above the TDI set by EFSA and just slightly below it for toddlers and adolescents. This indicates that a potential health concern for those three population groups cannot be excluded.

Heavy metals

Maximum levels of heavy metals in food have been set in the European legislation. However, not all of them have been regulated. A summary is presented in Table 1.

Table 1.

Maximum levels of heavy metals in food as per European legislation

Analyte	Food matrix	ML [mg/kg] (wet weight)	Regulation
Arsenic	Rice waffles, rice wafers, rice crackers and rice cakes	0.3	Commission Regulation (EU) 2015/1006 of 25 June 2015 amending Regulation (EC) No 1881/2006 as regards maximum levels of inorganic arsenic in foodstuff
Cadmium	Rye and barley	0.05	Commission Regulation (EU) 2021/1323 of 10 August 2021 amending Regulation (EC) No 1881/2006 as regards maximum levels of cadmium in certain foodstuffs
Lead	Cereals and pulses	0.2	Commission Regulation (EU) 2021/1317 of 9 August 2021 amending Regulation (EC) No 1881/2006 as regards maximum levels of lead in certain foodstuffs

Occurrence

The analytical determination has been carried out according the European standard EN 15763:2009 (European Committee for Standardization, 2009). The technique is based on inductively coupled plasma mass spectrometry (ICP‐MS) after pressure digestion. The implementation of this multielemental method of high sensitivity makes possible to determine several trace elements simultaneously.

Results of analytical measurement show that the mean is bigger than the median and skewness is positive. Therefore, it is assumed that data follow a log‐normal distribution. This is in line with what stated in literature: in the field of food contaminants, the log‐normality of the distribution is generally assumed (Kroes et al., 2002). Since the log of the measurements is normally distributed, it is more accurate to work with the logarithms of the measurements (Miller and Miller, 2010) and calculate the geometric mean UB. The value of the geometric mean UB is below the ML for every metal analysed. Results are summarised in Table 2.

Table 2.

Mean [μg/kg], median [μg/kg], standard deviation [μg/kg] and geometric mean UB [mg/kg] of heavy metals occurrence in rye‐wheat bread

Analyte	Mean [μg/kg]	Median [μg/kg]	Standard deviation [μg/kg]	Geometric mean UB [mg/kg]
Aluminium	4054.00	3919.00	1251.00	4.11
Arsenic	5.62	5.10	2.39	0.01
Cadmium	13.93	13.21	3.60	0.01
Chromium	134.61	106.17	84.5	0.13
Lead	82.39	72.50	54.33	0.08
Nickel	260.82	234.39	101.97	0.26

UB: upper bound.

Exposure assessment and risk characterisation

Chronic exposure to heavy metals was estimated for each population group by multiplying the 95th percentile consumption data (g/kg bw per day or week) with the upper level of the 95% confidence interval of the geometric mean.

Aluminium (Al). Food additives are reported to be the greatest contributors to intake of aluminium from food, but other sources also contribute to the overall intake, e.g. aluminium naturally present in plant products and migration from food contact materials. Plants can take up aluminium from the soil and from water in which aluminium (the third most abundant element, constituting approximately 8% of the earth's crust) is present. Therefore, the relatively high occurrence levels found in bread can be due to the widespread environmental occurrence of aluminium. From studies in the UK and France, cereals and cereal products, vegetables, and beverages appeared to be the main contributors (> 10%) to the dietary aluminium exposure. As also assessed by EFSA, cereals and cereal products, vegetables, beverages and certain infant formulae appear to be the main contributors to the dietary aluminium exposure (EFSA, 2008). In view of the cumulative nature of aluminium in the organism, the EFSA Panel considered it more appropriate to establish a tolerable weekly intake (TWI) of 1 mg/kg bw per week rather than a TDI (EFSA, 2008). The estimated weekly dietary exposure to aluminium exceeded the TWI for all populations groups. This is in line with the results reported by the EFSA Panel in the Scientific Opinion on Safety of aluminium from dietary intake where the TWI is likely to be exceeded in a significant part of the European population.

Arsenic (As). The largest contributors to overall total arsenic exposure seem to be ‘fish and seafood’ and ‘cereals and cereal products’. It should be noted that within the ‘cereal and cereal products’ food category, due to its high total arsenic amount, rice is one of the major contributors to the inorganic arsenic forms (EFSA, 2009a). The contribution (%) of rye‐wheat bread consumed in Poland to the total As dietary exposure have been calculated considering the occurrence data obtained from the analysis, and the inorganic arsenic input from ‘cereals and cereal products’ and the total arsenic dietary exposure of 95th percentile in different population groups reported in the EFSA opinion. The CONTAM Panel considered appropriate to set a range of BMDL₀₁ values to be used in the assessment instead of a single reference point (0.3–8 μg/kg bw per day) (EFSA, 2009a). The estimated total dietary exposures to arsenic for toddlers and other children are within the range of the BMDL₀₁ values identified by the CONTAM Panel for lung and bladder cancer and for dermal lesions. Therefore, the possibility of a risk to these population groups cannot be excluded. However, this does not necessarily indicate that children are at greater risk because the effects are due to long term exposure (EFSA, 2009a). For the others, the estimated dietary exposures are below 0.3 μg/kg bw per day. Therefore, the risk can be considered low for these population groups.

Cadmium (Cd). Cadmium absorption after dietary exposure in humans is relatively low (3–5%) but it is efficiently retained in the kidney and liver, with a very long biological half‐life ranging from 10 to 30 years. Cadmium is primarily toxic to the kidney, especially to the proximal tubular cells where it accumulates over time and may cause renal dysfunction. The CONTAM Panel identified the beta‐2‐microglobulin (B2M), a low molecular weight protein, as the most useful biomarker in relation to tubular effects. The food group that contributes to the major part of the dietary cadmium exposure, primarily because of the high consumption, is ‘cereals and cereal products’ (EFSA, 2009b). The total dietary Cd exposure has been calculated based on the data reported in EFSA Opinion and the occurrence data obtained from the analysis. Calculations have been based on the estimated average consumer exposure to cadmium by different food groups. It must be noticed that data on the estimated average consumer exposure to cadmium by different food groups reported in EFSA Opinion refers to the adult population. Therefore, calculations for toddlers and other children encompass a higher degree of uncertainty. The CONTAM Panel identified a benchmark dose lower confidence limit for a 5% increase of the prevalence of elevated B2M (BMDL₀₅) of 1.0 μg Cd/g creatinine. In order to remain below 1 μg Cd/g creatinine in urine in 95% of the population by age 50, the average daily dietary cadmium intake should not exceed 0.36 μg Cd/kg bw, corresponding to a weekly dietary intake of 2.52 μg Cd/kg bw (TWI). The dietary exposure to cadmium exceeds the TWI set by the EFSA Panel for the groups toddlers and other children. This might be primarily due to the greater amount of food consumed in relation to body weight.

Chromium (Cr). The EFSA CONTAM Panel decided to consider all the reported analytical results in food as Cr(III). In infants and toddlers the main contributors to the chronic exposure to Cr(III) were ‘foods for infants and small children’, followed by ‘milk and dairy products’ and ‘bread and rolls’. In the other age classes, the main contributors to the chronic exposure to Cr(III) were the food categories ‘milk and dairy products’ and ‘bread and rolls’. The total dietary Cd exposure has been calculated based on the data related to the contribution of the ‘bread and rolls’ category to the total dietary Cr exposure reported in EFSA Opinion for each population group (EFSA, 2014) and on the occurrence data obtained from the analysis. The CONTAM Panel derived a TDI of 300 μg Cr(III)/kg bw per day. Dietary exposure across all age groups are well below the TDI. Therefore, data indicates that dietary exposure to Cr(III) does not raise concern from a public health point of view.

Lead (Pb). Cereal products contribute most to dietary lead exposure. The total dietary exposure to Pb have been calculated considering the contribution of bread consumption to total dietary Pb exposure (%) corresponding to Poland reported in the EFSA Opinion on lead in food (EFSA, 2010) and the occurrence data obtained from the analysis. It must be noticed that the value of the relative contribution reported in the EFSA Opinion refers to the broad category ‘Cereals and cereal products’ and to the general population. Therefore, this information carries a quite high level of uncertainty. The CONTAM Panel identified developmental neurotoxicity in young children and cardiovascular effects and nephrotoxicity in adults as potential critical adverse effects of lead on which to base the risk assessment. A BMDL₀₁ intake level of 0.50 μg/kg bw per day for neurodevelopmental effects have been established for children. Whereas, BMDL dietary lead intake values in adults of 1.50 μg/kg bw per day and 0.63 μg/kg bw per day were derived for the cardiovascular and kidney effects, respectively. As there was no evidence for a threshold for a number of critical endpoints, the CONTAM Panel does consider it appropriate to calculate margins of exposure to support the risk characterisation. An MOE of 10 or greater would be sufficient to ensure that there was no appreciable risk of a clinically significant effect on neurodevelopmental, cardiovascular and kidney effects. Even at MOEs of greater than 1.0 the risk would be very low (EFSA, 2010). In all cases, the MOEs estimated in this work are below 1. Therefore, there is indication of health concern. This reflects the relatively high levels of Pb founded in the bread (geometric mean UB: 0.076 mg/kg). This is higher than the mean UB of Pb in ‘cereals and cereal products’ reported in the EFSA Opinion (0.044 mg/kg). However, the ML set for ‘cereals and pulses’ (0.2 mg/kg) has not been exceeded.

Nickel (Ni). According to the EFSA Opinion on Nickel in food and drinking water the food categories mainly contributing to the mean LB chronic dietary exposure to nickel across all age classes is ‘grains and grain‐based products’ with contributions reaching up to 49% in infants and toddlers. ‘Bread and rolls’ has the highest contribution among the food subcategories belonging to ‘grains and grain‐based products’. The mean nickel concentration levels for ‘bread and rolls’ are not particularly high; therefore, it is likely that their high contribution is driven by high consumption rather than the presence of nickel. The total dietary Ni exposure has been calculated based on the data related to the contribution of the ‘bread and rolls’ category to the total dietary Ni exposure reported in EFSA Opinion on Nickel in food and drinking water for each population group (EFSA, 2020) and on the occurrence data obtained from the analysis. An increased incidence of post‐implantation loss in rats was identified as the critical effect for the risk characterisation of chronic oral exposure and a BMDL₁₀ of 1.3 mg Ni/kg body weight per day was selected as the reference point for the establishment of a TDI of 13 μg/kg bw (EFSA, 2020). Mean chronic dietary exposure was the highest for toddlers. In this case the TDI is exceeded and it might indicate a concern.

3. Conclusions

3.1. The work programme

Results of the occurrence investigation work showed that rye‐wheat bread marketed in Poland has generally low levels of the chemical contaminants analysed. However, if the total dietary exposure to those contaminants is derived as described in the report, a public health concern cannot be excluded in some cases. A summary of the situations of higher risk is presented in Table 3.

Table 3.

Chemical contaminants rising a public health concern

Contaminant	Public health concern
Acrylamide	MOEs for neoplastic effects are far below the safe level across all age groups.
Deoxynivalenol	The estimate of chronic dietary exposure to DON for other children is above the TDI and just slightly below it for toddlers and adolescents.
Aluminium	The estimated weekly dietary exposure to aluminium exceeded the TWI for all populations groups.
Arsenic	The estimated dietary exposures to arsenic for toddlers and other children are within the range of the BMDL01 values.
Cadmium	The dietary exposure to cadmium exceeds the TWI for the groups toddlers and other children.
Lead	The MOEs are below the safe level across all population groups.
Nickel	The estimated dietary exposure to nickel exceeds the TDI for toddlers.

The exposure to AA and aluminium is of concern for all population groups. This is in line with what calculated by EFSA Panels (EFSA, 2008, 2015). The calculated exposure to lead rises concerns across all the population groups too. However, in this case results differs from what stated by the Panel in the Opinion (EFSA, 2010). The calculated high level of exposure is due to the relatively high concentration of Pb founded in the analysed bread in comparison with literature. In the other cases (deoxynivalenol, arsenic, cadmium and nickel), the most vulnerable groups are mainly toddlers and other children. This might be primarily due to the greater amount of food consumed in relation to body weight.

It is important to stress that the outcomes of scientific risk assessments should be evaluated along with uncertainties (EFSA, 2018b). On this regard, please see Appendix A.

It must be noticed that the type of bread analysed was made with refined flour. Health recommendations and dietary trends promote the consumption of wholemeal cereals. Since the outer hull of the grain has a higher concentration of contaminants such as AA (EFSA, 2015) and mycotoxins (Bergamini et al., 2010; EFSA, 2017), it might be valuable to assess the exposure of high consumers of wholemeal products.

Moreover, although the levels of the contaminants investigated in this study are below the MLs, it might be interesting to investigate eventual health consequences due to the cooccurrence of multiple chemicals in the same food matrix.

3.2. EU‐FORA

All in all, EU‐FORA is a key opportunity for early‐mid career food specialists and scientists. It fosters professional development through a comprehensive and multidisciplinary hands‐on experience in food safety risk assessment. Among the other benefits, it facilitates international collaborations and active involvement in the network of professionals in the area of food safety. The new skills and knowledge contribute to the development of solid scientific bases to better understand current and emerging food‐related issues. The gained expertise can be an asset in academia, public health bodies and food companies. Details regarding additional activities performed during the programme are reported in Appendix B.

Abbreviations

AA

acrylamide

ARfD

acute reference dose

B2M

beta‐2‐microglobulin

BMDL

benchmark dose lower confidence limit; 95%‐confidence lower bound

BMDL₀₁

95% lower confidence limit for the benchmark dose response of 1%

BMDL₀₅

95% lower confidence limit for the benchmark dose response of 5%

BMDL₁₀

95% lower confidence limit for the benchmark dose response of 10%

BVL

Federal Office of Consumer Protection and Food Safety

bw

body weight

CEN

European Committee for Standardization

CONTAM Panel

Panel on Contaminants in the Food Chain

DON

DEOXYNIVALENOL

DON‐3‐glucoside

Deoxynivalenol‐3‐glucoside

EU‐FORA

European food risk assessment

FAO

Food and Agriculture Organization

HBS

household budget survey

HPLC

igh‐performance liquid chromatography

IAFP

International Association for Food Protection

IBPRS ‐PIB

Prof. Wacław Dąbrowski Institute of Agriculture and Food Biotechnology

ICP‐MS

inductively coupled plasma mass spectrometry

INS

individual nutrition survey

LB

lower bound

ML

maximum level

MOE

margin of exposure

MRI

Max rubner‐institut

MTB

methyl tert‐butyl ether

NIV

nivalenol

NIV‐3‐glucoside

nivalenol‐3‐glucoside

NIZP PZH – PIB

National Food and Nutrition Institute – State Research Institute

RAFA

Recent Advances in Food Analysis

SD

standard deviation

SPE

solid‐phase extraction

TDI

tolerable daily intake

TWI

tolerable weekly intake

UB

upper bound

Appendix A – Uncertainties

Uncertainty analysis is the process of identifying limitations in scientific knowledge and evaluating their implications for scientific conclusions. In other words, uncertainty is used as a general term referring to all types of limitations in available knowledge that affect the range and probability of possible answers to an assessment question (EFSA, 2018a). The evaluation of the inherent uncertainties in the assessment has been mainly performed following the EFSA guidance related to Uncertainties in dietary exposure assessment and the guidance on uncertainty analysis in scientific assessments (EFSA, 2006, 2018a). Moreover, it is necessary to consider the uncertainties expressed by the EFSA Panels in the Scientific Opinions on each contaminant.

An attempt was made to provide a summary of the most important uncertainties and the relative magnitude and direction of their influence on the assessment output (Table A.1). The estimate of whether the source of uncertainty might have led to an over‐ or underestimation of the dietary exposure or the resulting risk has been performed with plus and/or minus signs. Plus signs for an uncertainty indicate that it could have caused small (+), medium (++) or large (+++) over‐estimation, minus signs that it could have caused small (−), medium (− −) or large (− − −) under‐estimation. Some uncertainties are evaluated as potentially causing either over‐ or under‐estimation (e.g. +/−).

Table A.1.

Summary of the most important uncertainties and the relative magnitude and direction of their influence on the assessment output

	Source of uncertainty	Direction and magnitude
Sample
Sampling strategy	Bread have been collected only in supermarkets	−/+
Exposure assessment
Food category	The food matrix analysed was ‘rye‐wheat bread and rolls, refined flour’. However, the consumption data present in the survey used as reference and in the EFSA Comprehensive European Food Consumption Database for Poland refer to the category ‘bread and similar products’	+
24‐h recall dietary survey	Some misreporting of consumption by individuals also occur (Kroes et al., 2002; Sekula et al., 2004)	−
	Food eaten away from home was excluded from the analysis (Sekula et al., 2004)	−
	Food consumption estimates are likely to be mutually dependent when subjects from the same household are interviewed, thus leading to a reduced variability in terms of dietary pattern observed (Food and Authority, 2011)	−/+
Acrylamide
Occurrence	Bread have been collected only in supermarkets	−
	Analytical analysis has been performed on bread after purchase. Therefore, home‐cooking habits (e.g. toasting) have not been considered	−
Exposure assessment	The subdivision of the population in age groups performed by the Polish National Food and Nutrition Institute (Mojska et al., 2010) does not perfectly correspond to the one commonly used by EFSA	−/+
Mycotoxins
Sampling strategy	Bread have been collected in a single sampling occasion. Mycotoxins level can vary between seasons and different years (Kroes et al., 2002; Bryła et al., 2018; Bryla et al., 2019; Ksieniewicz‐Woźniak et al., 2019)	−−/++
Heavy metals
	The total dietary intake of metals for the Polish population was calculated assuming that the contribution of bread consumption (%) to the total dietary intake (%) is the same as for the general European population.	−
	The food matrix analysed was ‘rye‐wheat bread and rolls, refined flour’. However, the data present in the EFSA's Opinions often refer to broader food categories.	−/+

Overall, the impact of the identified uncertainties is deemed moderate. In addition, it is important to notice that the impact of uncertainty elements can differ when considering different population groups.

Appendix B – Additional activities

Besides the work carried out at the hosting site, the participation to international events, conferences and trainings fostered the learning process and offered the stimulating opportunity get cutting‐edge insights on the latest developments and techniques in food science and safety, meet international experts working in industry, government, and academia and have a glimpse of the pivotal issues currently under the spot light of EFSA and the scientific community. Special mention deserves the participation as a speaker at the European Symposium on Food Safety 2022 organised by the International Association for Food Protection (IAFP) presenting in the symposium ‘New Hazards and Old Threats; Foodborne Viruses and Risk Assessment in Food Safety’ with the collaboration of other EU‐FORA colleagues (Kevin Hunt, Monika Trzaskowska and Constantine Richard Stefanou). Relevant event and conferences have been listed in Table B.1.

Table B.1.

Relevant events and conferences attended during the fellowship

Event/Conference	Date	Avenue
EFSA International Workshop on Risk Assessment of Combined Exposure to Multiple Chemicals	18, 19, 20 October 2021	Virtual
RAFA 2021 – Recent Advances in Food Analysis	3–4 November 2021	Virtual
EFSA Scientific Colloquium 26 on risk–benefit assessment of combined exposure to nutrients and contaminants through food	15, 16, 17 February 2022	Virtual
International Training for Safer Food ‐ 4th Federal Office of Consumer Protection and Food Safety (BVL)/Max Rubner‐Institut (MRI) Course on Food Safety, Food Authenticity and Risk Management	14, 15, 16 March 2022	Virtual
International Association for Food Protection (IAFP) – European Symposium on Food Safety	4, 5, 6 May 2022	Munich, Germany

Suggested citation: Balbo C and Woźniak Ł, 2018. Dietary exposure and risk characterisation of multiple chemical contaminants in rye‐wheat bread marketed in Poland. EFSA Journal 2022;20(S2):e200911, 14 pp. 10.2903/j.efsa.2022.e200911