Dietary acrylamide exposure among Finnish adults and children: the potential effect of reduction measures

A deterministic exposure assessment using the Nusser method that adjusts for within-subject variation and for nuisance effects among Finnish children and adults was carried out. The food consumption data covered 2038 adults (25–74 years old) and 1514 children of 1, 3 and 6 years of age, with the data on foods’ acrylamide content obtained from published Finnish studies. We found that acrylamide exposure was highest among the 3-year-old children (median?=?1.01?µg?kg^?1?bw^?day^?1, 97.5th percentile?=?1.95?µg?kg^?1?bw^?day^?1) and lowest among 65–74-year-old women (median?=?0.31?µg?kg^?1?bw^?day^?1, 97.5th percentile?=?0.69?µg?kg^?1?bw^?day^?1). Among adults, the most important source of acrylamide exposure was coffee, followed by casseroles rich in starch, then rye bread. Among children, the most important sources were casseroles rich in starch and then biscuits and, finally, chips and other fried potatoes. Replacing lightly roasted coffee with dark-roasted, swapping sweet wheat buns for biscuits, and decreasing the acrylamide content of starch-based casseroles and rye bread by 50% would result in a 50% decrease in acrylamide exposure in adults. Among children, substituting boiled potatoes for chips and other friend potatoes and replacing biscuits with sweet wheat buns while lowering the acrylamide content of starch-based casseroles by 50% would lead to acrylamide exposure that is only half of the original exposure. In conclusions, dietary modifications could have a large impact in decreasing acrylamide exposure.     

饼干中苯甲酸及其钠盐含量分析及其膳食暴露评估

对市场中210个饼干样品进行苯甲酸及其钠盐含量用HPLC方法进行测定,并对检测数据采用膳食暴露评估方法,评估城市居民的膳食风险。结果显示,婴儿(6～12个月)膳食暴露量为12.25～31.62μg/kg bw·d,其97.5/99百分位值的膳食暴露量为73.99～195.62μg/kg bw·d,建议婴儿(6～12个月)少量食用或食用不含苯甲酸的婴儿饼干。对于1～3岁的幼儿其膳食暴露量为10.25～13.25μg/kg bw·d,在97.5/99百分位值的膳食暴露量为105.24～139.10μg/kg bw·d,食用此类食品的风险是可以接受的。对于3岁以上人群食用此类食品的风险比1～3岁幼儿更小,风险程度更低。另外,饼干中威化和酥性类饼干中苯甲酸的残留水平相对于其他类饼干含量略高,而发酵和韧性类的饼干中苯甲酸的含量相稍低;同时显示江苏产的产品质量相对较好。     

Exposure of consumers to morphine from poppy seeds in Hungary

Poppy seed-containing foods are popular dishes in Hungary and some other Central European countries. The alkaloids of poppy are used in the production of medicines. Poppy seeds used as food may also contain considerable amounts of alkaloids, which raises the question of food safety. Morphine, codeine, thebaine and noscapine concentrations of poppy seed samples from the period 2001-2010 and consumption data from two Hungarian surveys, carried out in 2003 and 2009, were evaluated. Exposure calculations were made for morphine intake by both point estimate and probabilistic methods, and the uncertainty of the calculated values was estimated. The point estimate for the acute consumer exposure, calculated using the 97.5th percentiles of morphine concentration and of poppy seed consumption and taking into account the reduction of morphine content by processing, was 78.64?μg (kg?bw)?1?day?1 for adults, and 116.90?μg (kg?bw)?1?day?1 for children. Based on probabilistic estimations, the 97.5th and 99th percentile exposures ranged between 18.3-25.4 and 25.6-47.4?μg (kg?bw)?1?day?1 for adults, and between 32.9 and 66.4?μg (kg?bw)?1?day?1 for children, respectively. As a no observed effect level (NOEL) had not been established, the significance of exposure could not be assessed.     

Acrylamide-asparagine relationship in baked/toasted wheat and rye breads

Acrylamide in baked and toasted wheat and rye bread was studied in relation to levels of asparagine in flour, dough, bread and toasts. Asparagine was consumed during bread preparation resulting in reduced acrylamide content in the products. In wheat bread, 12% of the asparagine initially present in the flour (0.14 g kg(-1)) remained after yeast fermentation and baking; for rye bread, 82% of asparagine remained after sourdough fermentation and baking. Asparagine present in untoasted wheat bread had totally reacted after hard toasting. Toasted wheat and rye bread slices contained 11-161 and 27-205 microg kg(-1) acrylamide, respectively, compared to untoasted wheat and rye bread with <5 and 7-23 microg kg(-1) acrylamide, respectively. The dietary intake of acrylamide from bread (untoasted) of 2 microg day(-1) is relatively low; however, acrylamide exposure from bread increases several fold for people eating toasted bread.     

Acrylamide content of selected Spanish foods: survey of biscuits and bread derivatives.

An overview of the acrylamide content in commercial biscuits and bread derivatives (bread sticks, bread crust, crackers) marketed in Spain is presented. Acrylamide was determined by stable isotope dilution LC-MS with an LOQ of 30 microg kg(-1). Acrylamide content ranged from 5%) used in the formulation, but lower when functional ingredients, such as polyols, were used. An estimation of the acrylamide dietary exposure related to biscuits and bread derivatives was calculated as 0.082 microg kg(-1) day(-1). Estimated dietary intake were 0.002 and 0.058 microg kg(-1) day(-1) for crackers and biscuits, respectively.     

Contribution of selected foods to acrylamide intake by a population of Brazilian adolescents

Acrylamide dietary intakes from selected foods are estimated in this work for Brazilian adolescents from São Paulo State. The exposure assessment was carried out by combining levels of acrylamide in foods determined analytically by an accredited LC-MS/MS method, with individual food consumption data, using a deterministic approach. Data on food consumption were generated using 24 h recall applied to 578 individuals aged from 11 to 17 years, between July and August 2001. The mean and maximum acrylamide intakes were estimated to be 0.12 and 1.92 μg/kg bw/day, respectively. At 50th, 95th and 97.5th percentiles, the average intakes were 0.04, 0.55 and 0.77 μg/kg bw/day, respectively. Boys presented exposure levels lower than girls, while the acrylamide intake by younger adolescents (11-14 years) was higher compared to the older group (15-17 years). The foods that contributed most to acrylamide exposure were French fries, French bread, water and salt biscuit and coffee.     

广东省居民面制食品中铝的暴露评估研究

目的：了解广东省面制食品中铝污染的状况,并对居民来源于面制食品的铝摄入状况进行暴露评估。方法：2009年从广东省21个地市的超市、食杂店、集贸市场等随机采集面包、馒头、包子以及油饼油条类食品共840份,按照国家标准GB/T5009.182—2003《面制食品中铝的测定》方法测定其中的铝含量。将2002年广东省居民膳食营养与健康状况监测的调查人群按照不同的年龄、性别分成10组,分别计算面制食品消费量平均值和第97.5百分位数（P97.5）情况下各组人群铝的摄入情况。结果：面制食品中铝平均含量为210.30mg/kg,调查人群来自面制食品的平均铝摄入量0.10mg/（d.bw）,为每日可耐受摄入量（Acceptable Daily Intake,ADI）的0.73倍,从总体上看,2002年广东省营养与健康状况监测调查人群来源于面制食品的铝摄入水平是安全的。面制食品消费量为第97.5百分位数的情况下,调查人群总的铝摄入量为0.61mg/（d.bw）,为ADI的4.35倍,各组的铝摄入量平均值和第97.5百分位数铝摄入量分别为ADI的0.61—2.49倍、3.05—14.78倍,超出ADI倍数最高者为组1的2—7岁少年儿童。结论：需要关注广东省居民膳食铝食用安全情况,尤其是对生长发育阶段的少年儿童。在此基础上,尚需要纳入其它含铝高的食物调研,进行更加精细和全面的膳食铝健康危害风险评估。     

Estimation of long-term dietary exposure to acrylamide of the Japanese people

Acrylamide is a probable human carcinogen and known human neurotoxin. This study estimated hypothetical long-term dietary exposure to acrylamide of the Japanese people using probabilistic and deterministic approaches by combining the concentration of acrylamide in foods with the amount and frequency of food consumption in the population. Data included acrylamide concentrations in more than 2400 individual food samples from a national survey and the literature from 2004 to 2013. Food consumption amounts were derived from the data of 24,293 Japanese citizens aged 1 year and older in the 2012 National Health and Nutrition Survey. Median lifetime average dietary exposure to acrylamide was estimated as 147–154 ng/kg body weight (bw)/day (95th percentile, 226–261 ng/kg bw/day). The deterministic estimate of lifetime exposure was 158 ng/kg bw/day and ranged from 119 ng/kg bw/day for the period of life after 60 years old to 409 ng/kg bw/day for the period between 1 and 6 years old. This study found that vegetables cooked at a high temperature, coffee and cooked potato were the major food groups contributing to long-term dietary acrylamide exposure of the Japanese people.     

Dietary exposure to furan of the Austrian population

ABSTRACT

In the period from 2007 to 2017 furan levels of foods were analysed by the Austrian Agency for Health and Food Safety. Based on these analytical data and the Austrian consumption data the dietary exposure of children and adults to furan was estimated by using a deterministic approach. For the adult population the mean and 95^th percentile dietary exposures to furan were estimated at 0.31 µg/kg bodyweight per day and at 0.72 µg/kg bodyweight per day, respectively. The mean dietary exposure of children was estimated at 0.18 µg/kg bodyweight per day and is thus only about half as high as for Austrian adults. At the 95^th percentile the dietary exposure of children was estimated at 0.49 µg/kg bodyweight per day. The main contributor to the total dietary exposure for adults is coffee followed by convenience products and for children the main contributors are grain products as well as convenience products, bread and snacks. Based on the BMDL₁₀ of 0.064 mg/kg bodyweight per day for the development of cholangiofibrosis, the MOE-calculation revealed that the current levels of dietary exposure to furan are of concern for Austrian adult high consumers. The MOE-calculation, based on the BMDL₁₀ of 1.31 mg/kg bodyweight per day for the development of hepatocellular adenomas, indicated a health concern for Austrian children and adults.     

Exposure of consumers to deoxynivalenol from consumption of white bread in Hungary

In view of the frequent occurrence of mycotoxins in cereals, a study was initiated to assess the exposure of the Hungarian adult population. Consumption data for 1360 individuals, based on a 3-day questionnaire, indicated that white bread accounted for the major intake of cereal-based products. Various cereal products were analysed for 16 mycotoxins by a LC/MS/MS multi-toxin method with LOD of 16 μg kg?1 and LOQ of 50 μg kg?1. Deoxynivalenol (DON) was most frequently detected, but no acetyl-deoxynivalenol was present in detectable concentrations. Consumer exposure was calculated with standard Monte Carlo probabilistic modelling and point estimates, taking into account bread consumption and DON contamination in independently taken wheat flour and wheat grain samples. Over 55% of cases the DON intake were below 15% of the provisional maximum tolerable daily intake (PMTDI) of 1 μg/(kg bw)/day. However, in 5-15% of cases, the intake from bread consumption alone exceeded the PMTDI. Wheat grain data led to the higher percentage. Intakes estimated from both data sets were at or below the acute reference dose (ARfD) of 8 μg/(kg bw)/day in 99.94-99.97% of cases.     

Lead concentration in meat from lead-killed moose and predicted human exposure using Monte Carlo simulation

Lead-based hunting ammunitions are still common in most countries. On impact such ammunition releases fragments which are widely distributed within the carcass. In Norway, wild game is an important meat source for segments of the population and 95% of hunters use lead-based bullets. In this paper, we have investigated the lead content of ground meat from moose (Alces alces) intended for human consumption in Norway, and have predicted human exposure through this source. Fifty-two samples from different batches of ground meat from moose killed with lead-based bullets were randomly collected. The lead content was measured by atomic absorption spectroscopy. The lead intake from exposure to moose meat over time, depending on the frequency of intake and portion size, was predicted using Monte Carlo simulation. In 81% of the batches, lead levels were above the limit of quantification of 0.03 mg kg(-1), ranging up to 110 mg kg(-1). The mean lead concentration was 5.6 mg kg(-1), i.e. 56 times the European Commission limit for lead in meat. For consumers eating a moderate meat serving (2 g kg(-1) bw), a single serving would give a lead intake of 11 μg kg(-1) bw on average, with maximum of 220 μg kg(-1) bw. Using Monte Carlo simulation, the median (and 97.5th percentile) predicted weekly intake of lead from moose meat was 12 μg kg(-1) bw (27 μg kg(-1) bw) for one serving per week and 25 μg kg(-1) bw (45 μg kg(-1) bw) for two servings per week. The results indicate that the intake of meat from big game shot with lead-based bullets imposes a significant contribution to the total human lead exposure. The provisional tolerable weekly intake set by the World Health Organization (WHO) of 25 μg kg(-1) bw is likely to be exceeded in people eating moose meat on a regular basis. The European Food Safety Authority (EFSA) has recently concluded that adverse effects may be present at even lower exposure doses. Hence, even occasional consumption of big game meat with lead levels as those found in the present study may imply an increased risk for adverse health effects. Children and women of child-bearing age are of special concern due to the neurodevelopmental effects of lead.     

Assessment of the acrylamide intake of the Belgian population and the effect of mitigation strategies

The acrylamide (AA) intake of the Belgian consumer was calculated based on AA monitoring data of the Belgian Federal Agency for the Safety of the Food Chain (FASFC) and consumption data of the Belgian food consumption survey coordinated by the Scientific Institute for Public Health (3214 participants of 15 years or older). The average AA exposure, calculated probabilistically, was 0.4 µg kg^?1 body weight (bw) day^?1 (P97.5 = 1.6 µg kg^?1 bw day^?1), the main contributors to the average intake being chips (23%), coffee (19%), biscuits (13%), and bread (12%). Additionally, the impact of a number of AA mitigation scenarios was evaluated (German minimization concept, scenarios for mitigation from the literature, signal values), which is an important issue for public health as well as for policy-makers. Specific actions in cooperation with the food industry to reduce the AA content of foods seems to be a more efficient strategy than mere implementation of signal values. Considering that an important share of the AA intake is due to prepared meals, the catering industry as well as consumers need to be better informed on the various possibilities for keeping the AA content of meals as low as possible.     

Exposure of consumers to morphine from poppy seeds in Hungary

Poppy seed-containing foods are popular dishes in Hungary and some other Central European countries. The alkaloids of poppy are used in the production of medicines. Poppy seeds used as food may also contain considerable amounts of alkaloids, which raises the question of food safety. Morphine, codeine, thebaine and noscapine concentrations of poppy seed samples from the period 2001–2010 and consumption data from two Hungarian surveys, carried out in 2003 and 2009, were evaluated. Exposure calculations were made for morphine intake by both point estimate and probabilistic methods, and the uncertainty of the calculated values was estimated. The point estimate for the acute consumer exposure, calculated using the 97.5th percentiles of morphine concentration and of poppy seed consumption and taking into account the reduction of morphine content by processing, was 78.64?µg (kg?bw)^?1 day^?1 for adults, and 116.90?µg (kg?bw)^?1?day^?1 for children. Based on probabilistic estimations, the 97.5th and 99th percentile exposures ranged between 18.3–25.4 and 25.6–47.4?µg (kg?bw)^?1?day^?1 for adults, and between 32.9 and 66.4?µg (kg?bw)^?1 day^?1 for children, respectively. As a no observed effect level (NOEL) had not been established, the significance of exposure could not be assessed.     

Acrylamide–asparagine relationship in baked/toasted wheat and rye breads

Acrylamide in baked and toasted wheat and rye bread was studied in relation to levels of asparagine in flour, dough, bread and toasts. Asparagine was consumed during bread preparation resulting in reduced acrylamide content in the products. In wheat bread, 12% of the asparagine initially present in the flour (0.14 g kg^?1) remained after yeast fermentation and baking; for rye bread, 82% of asparagine remained after sourdough fermentation and baking. Asparagine present in untoasted wheat bread had totally reacted after hard toasting. Toasted wheat and rye bread slices contained 11–161 and 27–205 µg kg^?1 acrylamide, respectively, compared to untoasted wheat and rye bread with <5 and 7–23 µg kg^?1 acrylamide, respectively. The dietary intake of acrylamide from bread (untoasted) of 2 µg day^?1 is relatively low; however, acrylamide exposure from bread increases several fold for people eating toasted bread.     

Long-term daily intake estimates of polychlorinated dibenzo-p-dioxins and furans, polychlorinated biphenyls and polybrominated diphenylethers from food in Finnish children: risk assessment implications

Food is contaminated by polychlorinated dibenzo-p-dioxins and furans (PCDD/F), polychlorinated biphenyls (PCB) and polybrominated diphenylethers (PBDE) worldwide. Previous data show elevated intakes in children. We determined intakes of POPs in Finnish children. Because no children-specific safe limit values exist, we used tolerable daily intakes (TDIs) set for adults by international expert bodies to examine the proportion of the study population that exceed those limits. We utilised dietary monitoring data with food consumption of Finnish boys and girls aged 1-6 years, measured the contaminant concentrations in all the main food items and calculated age-specific contaminant sum and congener-specific long-term daily intake levels. Our food intake and contaminant data correspond to years 2002-2005. The long-term upper-bound dioxin intakes ranged between 0.1 and 12.8?pg WHO(PCDD/F-PCB)-TEQ/kg bw/d (min and max). An immediate TDI for WHO(PCDD/F-PCB)-TEQs of 4.0?pg/kg?bw/d were exceeded by 2.5%-7.5% of the children. PBDE long-term upper-bound intake was between 0.1 and 5.8?ng/kg bw/d (min and max). Congener-specific analyses indicated a typical Finnish adult exposure pattern of the children to PCDD/Fs, PCBs and PBDEs. The highest POP intakes were observed in children aged 3 years. Long-term daily PCDD/F, PCB and PBDE intakes among Finnish children varied greatly between individuals and ages. In each age group of the study population, there was a proportion of children with their WHO(PCDD/F-PCB)-TEQ intake exceeding considered safe limits set for adults. Based on the exposure profile reported herein, children should be clearly considered as a specific sub-population in food-mediated contaminant risk assessment.     

Dietary exposure to acrylamide in a group of Japanese adults based on 24-hour duplicate diet samples

Acrylamide is a probable human carcinogen and known human neurotoxin that can be generated in food through heating. Using a mathematical modelling approach, our previous study estimated long-term average dietary exposure to acrylamide in the Japanese people; however, the validity of these estimates remained unknown. Here, we aimed to obtain a more accurate estimate of acrylamide exposure that would reflect the usual practice of heat processing and consumption of foods in the population. We collected duplicate diet samples and dietary records during 24 h from a group of Japanese adults. A total of 110 duplicate diet samples were analysed for acrylamide by LC-MS/MS. Data from individual dietary records were used to examine the association between dietary acrylamide exposure and consumption of selected food groups (e.g., coffee, tea, confectioneries, and vegetables prepared at high temperature [deep-frying, stir-frying, sautéing, and baking]). Of the 110 homogenised diet samples, 108 contained detectable levels of acrylamide. Dietary exposure to acrylamide ranged from 8 to 1582 ng/kg body weight (bw)/day, with the mean value of 215 ng/kg-bw/day and median value of 143 ng/kg-bw/day. This mean value was higher than the value we previously estimated for Japanese adults using a mathematical approach. Multiple linear regression analysis showed log dietary acrylamide exposure was significantly associated with consumption of coffee and vegetables prepared at high temperature during 24-hr of sampling (adj. R² = 0.250, p < 0.001). We revealed significant difference in dietary acrylamide exposure between participants who had coffee and vegetables prepared at high temperature (median, 169 ng/kg-bw/day; range, 35–1224 ng/kg-bw/day, n = 42) and those who had none of them (median, 75 ng/kg-bw/day; range, 8–311 ng/kg-bw/day, n = 15) (Steel-Dwass test, p < 0.05).     

Risk assessment for furan contamination through the food chain in Belgian children

Young, old, pregnant and immuno-compromised persons are of great concern for risk assessors as they represent the sub-populations most at risk. The present paper focuses on risk assessment linked to furan exposure in children. Only the Belgian population was considered because individual contamination and consumption data that are required for accurate risk assessment were available for Belgian children only. Two risk assessment approaches, the so-called deterministic and probabilistic, were applied and the results were compared for the estimation of daily intake. A significant difference between the average Estimated Daily Intake (EDI) was underlined between the deterministic (419 ng?kg(-1) body weight (bw) day(-1)) and the probabilistic (583 ng?kg(-1) bw day(-1)) approaches, which results from the mathematical treatment of the null consumption and contamination data. The risk was characterised by two ways: (1) the classical approach by comparison of the EDI to a reference dose (RfD(chronic-oral)) and (2) the most recent approach, namely the Margin of Exposure (MoE) approach. Both reached similar conclusions: the risk level is not of a major concern, but is neither negligible. In the first approach, only 2.7 or 6.6% (respectively in the deterministic and in the probabilistic way) of the studied population presented an EDI above the RfD(chronic-oral). In the second approach, the percentage of children displaying a MoE above 10,000 and below 100 is 3-0% and 20-0.01% in the deterministic and probabilistic modes, respectively. In addition, children were compared to adults and significant differences between the contamination patterns were highlighted. While major contamination was linked to coffee consumption in adults (55%), no item predominantly contributed to the contamination in children. The most important were soups (19%), dairy products (17%), pasta and rice (11%), fruit and potatoes (9% each).     

The contribution of food groups to the nutrient intake and food pattern among pre-school children

A pre-school-based dietary survey, using 7-day records, was carried out in Sweden in the Stockholm area at 12 pre-schools; the survey included 109 of 131 participating children. The present study was designed to describe weekday and weekend food patterns, i.e. the frequency of consumption of food items and the contribution of energy and nutrient intake from different food groups, and to explore how foods are related in pre-school children's diet. At pre-school, all children except one ate vegetables and fruits about once a day, and all children consumed, on average, milk and cheese, meat products, bread and breakfast cereals and fats more than once a day. Milk and cheese products, bread and breakfast cereals and meat products were the primary source of energy and protein. The main source of dietary fibre was bread and breakfast cereals, potatoes and fruits. The “low-nutrient foods”, e.g. confectionery, buns, and soft drinks, contributed 20% of the energy during the weekdays and 33% during the weekend days. When all food groups (g/MJ) were analysed simultaneously in a Principal Components Analysis (PCA), 52% of the variation was explained. The food consumption data were described using four food clusters: milk and cheese products; bread and breakfast cereals; meat, potatoes and cooked cereals; confectionery, buns and soft drinks. In conclusion, the PCA seems to be a useful visual tool for elucidating how foods are related in the diet.     

Furan in heat‐treated foods: Formation,exposure, toxicity,and aspects of risk assessment

Furan is formed in a variety of heat‐treated foods through thermal degradation of natural food constituents. Relatively high levels of furan contamination are found in ground roasted coffee, instant coffee, and processed baby foods. European exposure estimates suggest that mean dietary exposure to furan may be as high as 1.23 and 1.01 μg/kg bw/day for adults and 3‐ to 12‐month‐old infants, respectively. Furan is a potent hepatotoxin and hepatocarcinogen in rodents, causing hepatocellular adenomas and carcinomas in rats and mice, and high incidences of cholangiocarcinomas in rats at doses ≥2 mg/kg bw. There is therefore a relatively low margin of exposure between estimated human exposure and doses that cause a high tumor incidence in rodents. Since a genotoxic mode of action cannot be excluded for furan‐induced tumor formation, the present exposures may indicate a risk to human health and need for mitigation. This review summarizes the current knowledge on mechanisms of furan formation in food, human dietary exposure to furan, and furan toxicity, and highlights the need to establish the risk resulting from the genotoxic and carcinogenic properties of furan at doses lower than 2 mg/kg bw.     

Estimation of dietary intake of melanoidins from coffee and bread

Melanoidins are defined as polymeric high molecular weight, brown-coloured Maillard reaction end-products, containing nitrogen. They escape digestion and pass through the upper gastrointestinal tract and can interact with the different microbial species present in the colon. Major dietary sources of melanoidins are coffee and bread crust. Both coffee and bread crust melanoidins can be fermented by the human hindgut microflora thus sharing some of the properties attributed to dietary fibre. Despite the emerging positive physiological properties of such dietary constituents their intake has not been estimated yet. To this aim melanoidin content in different type of coffee brews, bread and dry biscuits was determined by sequential ultrafiltration and enzymatic digestion. Despite some drawbacks and limiting steps in the calculation, such as the lack of a reference material, an educated guess on the dietary intake of melanoidins has been put forward. Data indicated that the intake of coffee melanoidins ranged between 0.5 to 2.0 g per day for moderate and heavy consumers, respectively. For bread and dry biscuits an intake in the ranges of 1.8-15.0 and 3.2-8.5 g per day has been calculated. These figures suggest that a realistic estimation of melanoidins dietary intake for general population would be close to 10 g per day considering all the possible alimentary sources.