7. HEALTH EFFECTS AND RISKS OF HUMAN DIETARY EXPOSURE TO CONTAMINANTS IN FOOD CHAINS |
7.1 Organisation of monitoring activities
This subsystem comprises five parts and is carried out in 12 cities (see Tab. 3.1). The number of locations was selected so as to provide a uniform representation of the regions involved. The five parts are as follows:
1) Monitoring and evaluation of reports of food-borne alimentary infections and cases of poisoning, utilising the EPIDAT epidemiological database and reports by the Public Health Service.
2) Monitoring the occurrence of selected pathogenic bacteria in sampled foodstuffs. Bacterial strains isolated from foodstuffs undergo further qualitative analysis, including testing for antibiotic resistance and, in the case of Listeria, quantitative determination of KTJ/g.
3) Monitoring the incidence of toxic micromycetes (moulds) in sampled foodstuffs. Micromycete isolates are classified by genus and species and their toxicity (particularly production of aflatoxins and ochratoxins) is studied.
4) Monitoring of genetically modified foodstuffs commercially available in the Czech Republic. Inclusion of this new part into the subsystem is a response to public demand and EU requirements. The second, third and fourth projected parts continued as pilot studies in 2003.
5) Monitoring of population dietary exposure to selected chemicals. Food samples are collected in one location where they undergo standard culinary preparation and are subsequently analysed for content of selected chemicals.
All results serve to assess exposure and to characterise the health risks associated with population nutrition in the Czech Republic.
7.2 Incidence of alimentary infections and poisoning
Monitoring of reported cases of food-borne infections is carried out in 12 selected regions in the Czech Republic: Benešov, Brno, České Budějovice, H. Králové, Jablonec nad Nisou, Ostrava, Plzeň, Prague, Šumperk, Ústí nad Labem, Znojmo and Žďár nad Sázavou. Monitoring of alimentary infections and poisoning has been carried out since 1993 and focuses on the most common etiological agents: Salmonella spp., Campylobacter jejuni, Shigella spp., Citrobacter freundii, E. coli, Yersinia enterocolitica, Staphylococcus aureus, Clostridium perfringens, adenoviruses, rotaviruses and type A hepatitis viruses. Epidemiological data reported in 2003 (annual incidence, distribution of cases by gender, age, ethnic background, season, epidemic incidence) are compared in the 12 selected localities with nationwide data pertaining to the Czech Republic and previous years.
In the Czech Republic in 2003, a total of 26,899 cases of salmonella were reported (264 cases per 100,000 population). This represents the lowest annual incidence over the past eleven years, since 1993. Since 1999, the trend of salmonella cases has been steadily declining. In 2003 there were 17,912 fewer cases than in 1999 (total no. of cases 44,811) and 1,065 cases less than in 2002. Reported morbidity since 1993 is shown in Fig. 7.1. Of the 12 regions monitored, in 2003 morbidity declined in 5 regions and remained at the 2002 level in Prague; the remaining six regions had lesser or greater increases (Benešov, Hradec Králové, Jablonec nad Nisou, Plzeň, Šumperk and Znojmo). The highest morbidity in 2003 was yet again reported in Znojmo, as in 2001 and 2002 (489 cases per 100,000 population). Znojmo also has the highest morbidity for the 1999–2003 period (563 cases per 100,000 population). From a total of 26,899 cases of salmonella, 40 were classified as septic, almost half of this number invloving persons aged 65 years or older. Carriers of S. Enteritidis without clinical signs numbered 579 persons. A total of 21 cases were fatal, of which 17 were due to salmonella, 3 due to septic salmonella and one involved a carrier. The major etiological agent in 2003 remained S. Enteritidis, which comprised 95.7 % of isolated salmonellae. S. Typhimurium (STM) rates in the Czech Republic dropped from 2 % in 2002 to 1.6 % in 2003. The highest rates of STM were again reported in Prague (11.8 % in 2003) and Brno, although the latter region had a small decline from 7 % in 2002 to 5 % in 2003. Further analyses conducted in 2003 revealed the continuing greater ratio of female cases, highest morbidity in the 1–4 years age-group and peak seasonal incidence in August. A total of 33 salmonella epidemics was recorded, with an average of 19 cases per epidemic. The majority of epidemics occurred in Prague (14) with an average 33 cases per epidemic. The greatest epidemic outbreak, involving 137 cases and 916 persons exposed, occurred in April 2003 at a secondary school in Prague district 8. The vehicle in this case was a chicken-based school meal.
Campylobacteriosis is the second most frequent bacterial alimentary infection with marked epidemiological importance. In 2003, the incidence of this disease declined. 20,063 cases were reported in the Czech Republic, 3,143 cases less than in 2002. Reported morbidity since 1993 is presented in Fig. 7.1. Morbidity in the Czech Republic comprises 197 cases per 100,000 population, and is most frequent in the Brno region (458) and in Benešov (394). The major etiological agent is Campylobacter jejuni. The age range for reported cases of campylobacteriosis is equivalent to that of salmonellosis (children aged 1–4 years are the most frequently afflicted group). Seasonal incidence has a characteristic curve with a prominent peak in August.
The annual number of reported cases of shigellosis in 2003 is 381 (95 cases more than in the previous year and 27 cases more than in 2001). The sharp decline in morbidity evident since 1993 has therefore ceased, and it remains to be seen whether or not this is a transient phenomenon. The morbidity rate is about 4 persons per 100,000 population and half of the mean annual morbidity for the Czech Republic during the 1993–2003 period (7.7), during which the highest rates were recorded in Hradec Králové (25.7) and Ústí n. Labem (25.1). The highest morbidity in 2003 was reported in České Budějovice (5.6). As was the case in 2001 and 2002, no single case was reported in Benešov. Traditionally, the major etiological agent was Shigella sonnei, its ratio in 2003 was 68 %. The ratio of diseases caused by Shigella flexneri rose from 15 % to 25 %, Shigella boydii rose to 3 % and Shigella dysenteriae dropped from 4 % to 0.3 %.
The annual incidence of infections caused by E. coli was slightly higher in 2003 (14 cases more). Over the past two years, morbidity in the Czech Republic has amounted to about 15 cases per 100,000 population. This average value was exceeded in 2003 in the Ústí n. Labem region (26.4). No cases were reported in Hradec Králové and Znojmo. E. coli infection mainly affected children up to 4 years of age in 2003. The seasonal characteristics of this infection mean that the majority of cases are registered in August. Identified serovars in 2003 differed from the previous year: the number of serovars 055 and 0125 increased, 018 and 0126 decreased significantly and 0157 decreased to the lowest rate since 1998 (35); the latter serovar does not, so far, play an important epidemiological or medical role in the Czech Republic, unlike other countries such as Great Britain or Japan.
In 2003, 372 cases of yersiniosis were reported in the Czech Republic (4 cases per 100,000 population), 31 cases less than in 2002. The sole origin is Y. enterocolitica. The highest morbidity was recorded in Ostrava (18 cases per 100,000 population), as has been the case since 1993. Half of the monitored 12 regions reported no cases at all. The highest specific morbidity was in the 0–4 age group. The seasonal curve is lowest in February–April.
Cases of viral gastroenteritis are presented as infections of adenoviral, Norwalk and rotaviral etiology. Adenoviral infections numbered 285 in 2003, or 174 cases more than in 2002. No cases of the disease caused by Norwalk virus were reported in 2003, as was the case in 2000 and 2002 (in 2001 there were 104 cases), whilst cases of infection by rotavirus dropped by 34 cases against 2002 (1,541 cases), numbering almost double the rate in 2000. Morbidity is 15 cases per 100,000. The greatest number of cases was registered in Ostrava (185 cases), Prague (123) and Pilsen (109), where the incidence of rotaviruses in 2000 exceeded that of 2002 as compared to the other six regions. Of the 12 monitored regions, half has many years of experience in the study of rotaviruses.
Reported incidence of alimentary infection in 2003 is the lowest since 1998 (61 cases). The incidence curve for these infections has an evenly declining tendency, with the exception of 2000 when a peak of 1,093 cases was recorded. Of 12 monitored areas, only 3 (Ostrava, Prague and Žďár nad Sázavou) reported cases of infection. Of 61 reported cases of intoxication, 18 were bacteriologically positive; in 14 cases the causative agent was Staphylococcus aureus (77 %). Type A Clostridium perfringens was identified in one case. The number of cases not examined in 2003 is 70 %, only 7 % less than in 2002.
In 2003, 114 cases of viral hepatitis type A (VHA) were reported. This is 13 cases less than in 2002 and 500 cases less than in 2000. Morbidity caused by this infection is declining each year; in 2000 this represented 6 cases per 100,000 population, and 1 case per 100,000 population in 2003. Mean morbidity during the 1993–2003 period was 11 cases per 100,000 population. Morbidity declined in all regions except Brno, Prague and Šumperk, which had the greatest morbidity in 2003 (6.4). Analysis by gender revealed greater morbidity in men in recent years; the proportion of infected Romany subjects was 27 %. The 5–9 year age group is most at risk. Parenteral transmission was insignificant according to avaialble documentation; this does not reflect the actual state of affairs. In 30 % of cases contact with an infected person was cited; in 4 % contact was with a carrier. In 55 % of cases the route of transmission was not identified; this is the highest percentage in recent years.
Reported morbidity per 100,000 population in the Czech Republic for the most important alimentary infections for the 1994–2003 period is presented in Tab. 7.1.
7.3 Bacteriological analysis of foodstuffs
In this study focused on bacteriological analysis of foodstuffs the incidence of selected pathogens in foodstuffs from the consumer network was monitored during 1999–2003. The selection of commodities analysed was based on the consumer food-basket and targeted those foods that have in the past been involved in alimentary infections in the Czech Republic and abroad. A group of 4 major originators of alimentary infections was targeted: Salmonella spp., Campylobacter spp., Listeria monocytogenes and E. coli 0157. Apart from salmonella, the other bacterial agents are monitored only rarely as part of routine checks of food safety; hence, information about their incidence in individual commodities in the Czech Republic is virtually non-existent. Microbiological analysis was performed in line with valid standards in the Czech Republic. Isolates were confirmed biochemically; serotypes were obtained for salmonella and L. monocytogenes. Salmonella isolates were tested for antibiotic resistance and S. Enteritidis and S. Typhimurium were phage typed.
In the period 1999–2003, a total of 2,040 food samples was examined for the presence of salmonella. The samples comprised meat, offal, fish, poultry, oven-ready meals and confectionery. Positive findings were isolated in 57 cases. Salmonellae were detected in samples of eggs (23.3 %) and poultry (12.1 %). The most frequently detected salmonellae were S. Entertidis SE (27x) and S. Typhimurium (STM) (12x). Phagotype subtyping was conducted on 27 isolates of SE, phagotype PT8 being the most common. Among 12 isolates of STM, DT104 was most frequent. Five isolates of STM DT104 were multiresistant: one of the isolates from an egg was resistant to 8 antimicrobial substances.
From the total of 840 food samples campylobacter was detected in 45 cases (mainly poultry and offal).
3,060 samples of meat, dairy, fish, vegetables, dried fruit, delicatessen and confectionery products were tested for presence of L. monocytogenes (LM). Of these, 148 were positive. L. monocytogenes was most frequently detected in samples of various raw meat, offal and frozen vegetables. In 2003, a method was introduced for determination of LM; in 19 of 22 positive samples the count was under 100 KTJ LM.g-1, in two cases the count reached 100 KTJ LM.g-1 and in one sample of confectionery the figure detected was 9.8.103 KTJ LM.g-1. Serotype group 1/2 was the most frequent.
1,380 samples of meat, dairy products, spices and vegetables were tested for presence of E. coli 0157. The presence of this pathogen was not confirmed in any of the samples.
7.4 Mycological analysis of foodstuffs
2003 was the 5th year of the ‘MYKOMON’ project. The incidence of toxic micromycetes (fungi) – producing aflatoxins and ochratoxin A – was monitored in selected consumer foods. Specialised mycological examination was directed at description and characterisation of the danger of toxic micromycetes in foodstuffs. As in previous years, a total of 300 samples of food was taken on four separate occasions at 12 sites throughout the Czech Republic.
Total micromycete count was determined for each sample (KTJ/g) and the mycological profile was identified. The incidence of monitored micromycetes was expressed as a contamination index (Ik) – in other words, the ratio of potentially toxic micromycetes (KTJ/g food) to the overall micromycete count (KTJ/g).
The presence of potentially toxic micromycetes Aspergillus flavus, producers of aflatoxins, was determined in 26 samples (22 %) of the following foodstuffs: rice, caraway seeds, sweet paprika, black tea, fruit tea, semolina, flour and oat flakes. Of the isolated strains of Aspergillus flavus, 16 (62 %) were evaluated as toxic. Their toxicity was confirmed by determination of aflatoxin production on cultivation medium.
Incidence of toxic strains Aspergillus flavus in foodstuffs during 1999–2003
|
1999 |
2000 |
2001 |
2002 |
2003 |
Frequency (%) |
28 |
17 |
18 |
17 |
22 |
Toxic strains (%) |
75 |
63 |
77 |
56 |
62 |
Foods |
black tea, fruit tea, |
black tea, |
black tea, fruit tea, |
black tea, fruit tea, |
black tea, fruit tea, |
The presence of toxic micromycetes Aspergillus tamarii, producers of aflatoxins, was detected in 3 samples (25 %) of black tea. Of the isolated strains of Aspergillus tamarii, 1 (33 %) was identified as toxic. Its toxicity was confirmed by determination of aflatoxin production on cultivation medium. Aflatoxin B1 was detected in 1 sample (8 %) of sweet paprika (4.3 µg/kg). Aflatoxin G1 was detected in the same sample (6.2 µg/kg).
Incidence of toxic strains Aspergillus tamarii in foodstuffs during 1999–2003
|
1999 |
2000 |
2001 |
2002 |
2003 |
Frequency (%) |
25 |
25 |
21 |
17 |
25 |
Toxic strains (%) |
100 |
67 |
80 |
25 |
33 |
Foods |
black pepper |
black tea, |
black tea, |
black tea, |
black tea |
Potentially toxic micromycetes Aspergillus sk. niger (producers of ochratoxin A) were detected in 26 samples (36 %) of the following food samples: rice, raisins, caraway seeds, black pepper, black tea and fruit tea. Ochratoxin A was determined in 3 samples (25 %) of raisins (arithmetic mean 2.3 µg/kg, maximum value 3.0 µg/kg).
Incidence of potentially toxic strains Aspergillus sk. niger in foodstuffs during 1999–2003
|
1999 |
2000 |
2001 |
2002 |
2003 |
Frequency (%) |
67 |
85 |
32 |
48 |
36 |
Foods |
black tea, fruit tea, |
black tea, fruit tea, |
black tea, fruit tea, |
peanuts, black |
black tea. fruit tea, |
As in previous years Penicillium crustosum (potential producer of the mycotoxin penitrem A) was detected in walnuts.
Incidence of toxic strains Penicillium crustosum in walnuts during 1999–2003
|
1999 |
2000 |
2001 |
2002 |
2003 |
Frequency (%) |
25 |
25 |
33 |
33 |
50 |
7.5 Incidence of genetically modified foods commercially available in the Czech Republic
In 2003, ‘GENOMON’ was in its second year of activity; selected samples of food were monitored to detect their potential content of genetically modified organisms.
As in 2002, total of 192 samples of food (48 samples of tomatoes, 48 samples of Soya beans, 48 samples of Soya products, and 48 samples of corn flour) were collected on 4 occasions at 12 sites in the Czech Republic.
The samples were analysed by polymerase chain reaction method (qualitative screening determination by PCR), semiquantitative immunochemical methods (ELISA) and quantitative PCR method in real time (RT-PCR). Of 192 samples analysed, 5 samples of Soya products and 1 sample of Soya beans were evaluated as positive.
Summarised results of tests for the presence of GM raw materials in foodstuffs in 2002 and 2003
Food |
No. of samples examined |
Positive (no./%) |
Negative (no./%) |
|||
2002 |
2003 |
2002 |
2003 |
2002 |
2003 |
|
Tomatoes |
48 |
48 |
0/0 |
0/0 |
48/100 |
48/100 |
Soya beans |
48 |
48 |
6/12.5 |
1/2.1 |
42/87.5 |
47/97.9 |
Soya products |
48 |
48 |
18/37.5 |
5/10.4 |
30/62.5 |
43/89.6 |
Cornflour |
48 |
48 |
0/0 |
0/0 |
48/100 |
48/100 |
Total |
192 |
192 |
24/12.5 |
6/3.1 |
168/87.5 |
186/96.9 |
RT-PCR method determined that the amount of Roundup Ready soya (RRS) present in Soya beans and Soya products was below 1 % in 5 cases. Only one sample of Soya products had an RRS content in excess of 1 %. Samples from 2002 was likewise analysed by RT-PCR.
Comparison of RRS content in foods for 2002 and 2003 (RT-PCR results)
Food |
Positive samples (no.) |
No. of samples containing |
No. of samples containing |
|||
2002 |
2003 |
2002 |
2003 |
2002 |
2003 |
|
Soya beans |
6 |
1 |
4 |
1 |
2 |
0 |
Soya products |
18 |
5 |
9 |
4 |
9 |
1 |
Total |
24 |
6 |
13 |
5 |
11 |
1 |
The results demonstrate that on the market is available food containing RRS (40-3-2), which has been sanctioned in the Czech Republic as a new food product. In 2003, fewer samples of RRS in Soya beans and products were detected than in 2002. None of the positive samples of food were designated as produced from genetically modified material. While in 2002 such designation was mandatory from 1 % and higher (Act No. 110/97), the present level is 0.9 % (see EU directive No. 1829/2003). During 2003, no new data was presented to describe health risks ensuing from approved GMO.
7.6 Human dietary exposure
The major objective of the monitoring programme has remained the assessment of mean population exposure in the Czech Republic to selected chemicals (significant contaminants, nutrients and micronutrients). Their presence in foodstuffs may pose health risks of a carcinogenic and non-carcinogenic nature. In 2003, 2 values of expected food consumption were used for estimation of exposure doses: actual value of consumption (according to the so-called consumer basket for the Czech Republic, representing the mean availability of foods for each family member in 1994) and a model of recommended food doses. The set of samples supplied for analyses comprised 195 separate types of food from 4 regions of the Republic (12 areas, region A = Plzeň metropolis, České Budějovice, Benešov, region B = Ústí nad Labem, Jablonec nad Nisou, Prague, region C = Hradec Králové, Šumperk, Ostrava, region D = Žďár nad Sázavou, Brno, Znojmo). The total amount of samples equalled 2,340 over a 1-year period. For economic reasons, the food samples were combined into so-called composite samples according to region. Samples representing each region were subjected to standard culinary treatment and mixed into 108 types of composite sample for each of the 4 regions of the Republic. A total of 432 composite samples were prepared for analysis of basic content of chemical substances. For determination of certain substances the composite samples from separate regions were further mixed so that the Republic is represented by 108 mixed composite samples. Certain special analytical determinations (toxic congeners PCBs, dibenzofuranes, dioxins, nitrites etc.) required a different, rationally based selection or combination of food samples. A total of 86 separate chemical substances was quantified in food samples. The following analytes were newly studied in 2003: acrylamide, organic tin compounds (OTC) and polyaromatic hydrocarbons. Detected concentrations of chemical substances were used for calculating estimates of mean exposure doses for the population of the Czech Republic, based on data pertaining to actual food consumption according to the consumer basket. For long-term comparison of exposure doses (since 1994) a model of recommended food doses for CZ was used, based on 5 population groups (children, men, women, pregnant/lactating women, older persons, see Tab. 7.2). This model facilitates standardisation of results and hence long-term monitoring of trends in changes of concentration of chemical substances in foodstuffs.
In 2003, the mean chronic exposure population dose of monitored organic substances (PCBs, aldrin endrin, dieldrin, methoxychlorine, endosulphane, heptachloroepoxide, heaxachlorobenzene, alpha-, beta-, delta-, gamma- (lindane) isomers of hexachlorocyclohexane, isomers of DDT, DDD, DDE, alpha-, gamma-, oxy- chlordan, mirex) from foodstuffs did not exceed critical values associated with inadmissibly heightened risk of consumer health damage (non-carcinogenic). Population exposure estimated according to actual consumption was again highest for PCBs. Exposure to the sum of 7 PCB indicator congeners reached a mean value of approximately 8.7 % of the tolerable daily intake (TDI). In fact the value is lower, what is indicated by skeleton analysis with aid of more sensitive method (3.8 %). The highest number of positive findings using analytical methods with increased sensitivity was observed at PCB congeners nos. 138, 153 and 180 (70, 68 and 53 %). A high number of positive findings was repeatedly found in p,p´DDE (82 %). A high number of positive findings was likewise observed in o,pDDD (58 %), in HCH gamma isomers (49 %) and in HCB (41 %). The exposure doses were again very low (0.2 % PTDI for ‘the sum of DDT’ = p,p´DDT+o,pDDT+p,p´DDD+p,p´DDE and 2.8 % TDI for HCB). This reflects a persistent overall contamination with these organic pollutants but at very low levels with no substantial significance to consumer health.
In 2003, the estimate of the exposure dose to substances with the so-called ‘dioxin-effect’ (TEQ 2,3,7,8-TCDD for the sum of 29 PCB toxic congeners, dioxins and dibenzofurans) was about 8.1–9.6 pg WHO TEQ TCCD/kg b.w./week. This is equivalent to about 58–69 % TWI (EU), a value within the boundaries of estimated exposure doses from previous years. However, this relatively positive result should not be over-estimated in view of the very low number of analysis results (4/year). In the so-called dioxin toxicity there take a share PCBs 55–65 %, dibenzofurans 30–34 % and dioxins 1–15 %.
Exposure doses estimated according to the model of recommended food doses logically reached the highest values in children aged 4–6 years. Exposure to the sum of 7 PCB indicator congeners was practically the same as in the previous year reaching a level of 33 % TDI (Fig. 7.3a).
Mean chronic population exposure to inorganic substances (nitrates, nitrites, cadmium, lead, mercury, arsenic, copper, zinc, manganese, selenium, magnesium, chromium, nickel, aluminium, iron and iodine) did not exceed exposure limits for non-carcinogenic effects. Exposure estimated from the consumer basket, after years of increase, has a moderate decline for nitrates (16 % ADI) and a fluctuating load for nitrites (following a decrease to 9 % in 2001, a repeated rise to 20 % ADI in 2002, in 2003 slight decline to 19 %). Manganese intake is decreasing (36 % RfD). The cadmium load is practically the same as in the previous year (19 % PTWI). The lead load continues to decline (6 % PTWI). The mercury load has decreased (1.3 % PTWI), and likewise highly toxic methylmercury (4 % PTWI). Copper and zinc remain low (3 % PMTDI and 16 % PMTDI, respectively). Arsenic exposure (“toxic” arsenic – anorganic compounds) has again decreased slightly (3.5 % PTWI). Selenium intake decreased slightly (14 % RfD). The estimate of the nickel and chromium intakes remain at low levels with a fluctuating tendency (8 % RfD and 24 % RfD). Estimated exposure to aluminium and iron has not shown any risk of consumer health impairment (4 % PTWI and 19 % PMTDI). An estimate of the contaminant intake for the average person is shown in Fig. 7.2 and Tab. 7.3.
Exposure estimated according to the model for recommended doses of foodstuffs has again reached the highest values in the 4 to 6-year age group. Exposure to nitrates reached about 76 % ADI (the contribution from vegetables is also included), while exposure to manganese has decreased to 140 % RfD. These results are only rough because the form of manganese has not been determined. PCB exposure levels do not seem to be influenced by the floods of 2002.
In 2003, the following chemicals either continued to be monitored or were newly added: a set of 15 polycyclic aromatic hydrocarbons (PAHs) in all types of foods, acrylamide in 20 selected groups of foods and 8 organic tin compounds (OTC) in 5 groups of fish and fish products. All exposure estimates were rather encouraging. For instance, the benzo[a]pyrene exposure level was only 0.002 µg/kg body weight/day and exposure to sum PAHs was below 1 µg/kg body weight/day. Based on analysis of 20 indicated groups of foods, the acrylamide exposure level was estimated to be 0.3 µg/kg body weight/day. OTC exposure level only reached 0.005 µg/kg body weight/day (about 2 % of the suggested TDI), with tributyltin being the major pollutant. Nevertheless, additional data are needed for a more reliable interpretation.
Evaluating the intake of certain trace elements (zinc, copper, selenium, chromium, nickel, manganese, magnesium, calcium, phosphorous, sodium, potassium, iron) according to the consumer basket the following exposure doses have been revealed: 111 % of the population normative minimum for zinc, 93 % for copper (below the value of the population normative minimum, but nevertheless higher than in 2002). Despite the slight decrease of selenium intake, the need was covered for the normative minimum (127 %). The recommended intake was tapped 133 % for chromium, 275 % for nickel, 101 % for manganese, 73 % for magnesium, 86 % for calcium, 175 % for phosphorus. The upper intake limit for sodium was tapped from 78 % (e.g. 136 % of the N.A.S. USA recommendation), 81 % for potassium (the intake ratio of Ca/P was repeatedly low and worse than in 2002, while that of Na/K was relatively high). The iron intake was slightly higher, but reached only 70 % of the recommended dose. In the case of using iodised salt for culinary purposes the recommended iodine intake was covered by 153 % and the increase of the model exposure in children after food fortification needs attention.
Exposure to trace elements estimated according to the model for recommended doses of foodstuffs reached the lowest values in the age group of over 60 years. The pattern of food consumption in the spectrum of recommended doses does not cover the recommended intake in certain minerals. On the other hand, in children there could be serious problems in the future through uncontrolled food fortification with some microelements.
A theoretical estimate of probable increase in the risk of contracting cancer resulting from dietary exposure (mean of exposure doses according to the consumer food basket) to selected chemicals (sum of 7 indicator PCB congeners, alpha- and beta- isomers of HCH, lindane, p,p´- isomers of DDT, DDD and DDE, aldrin, dieldrin, heptachloroepoxide (A + B), HCB, and toxic arsenic) amounted to about 65 additional cases in the Czech Republic in 2003. Traditionally, PCBs (37 cases) and arsenic (16 cases) represented the greatest share in this increase. The contribution of chlordane to the risk increase seems repeatedly to be negligible (0.11 cases). The estimate for chemicals with a dioxin effect (expressed as the sum of TEQ TCDD for 29 congeners of PCBs, dioxins and dibenzofurans) amounted to about 24–29 cases for the Czech Republic and the year 2003.
7.7 Partial conclusions
Results of the analysis of notified alimentary infections in 2003 do not differ distinctly from those in preceding years. The number of reported cases is decreasing.
Results of microbiological analyses suggest which commodities in the market network are most frequently contaminated with pathogenic agents, and serve to obtain a more precise conception of the causes of alimentary infection. The most frequently detected contaminant was L. monocytogenes.
Samples taken simultaneously for mycological analysis confirm the presumption of the relatively frequent incidence of toxigenic micromycetes Aspergillus flavus, Aspergillus tamarii (producers of mycotoxins – aflatoxins) and Aspergillus niger (producers of ochratoxin A) in certain kinds of foodstuffs.
There are virtually no foods labelled as made from GMO on the market. The presence of GMO was detected in only 2 % of analysed samples of Soya beans and 10 % of Soya products. Quantitative analysis shows that only one sample should be designated as GMO; this should be considered a favourable result. The data does not reveal increased health risk, as assessed on the basis of current knowledge.
Results of monitoring the exposure to certain hazardous chemicals from foodstuffs in the Czech Republic confirm slight fluctuations of exposure doses in connection with changes in concentration levels. The characterization of the health risk appears to be relatively favourable for the average person in the population. In number of persisting contaminants the values of exposure doses have decreased or remained at low levels. Assessment with the aid of the model of recommended food doses revealed certain health risks, particularly for children (greater exposure to chemicals or to minerals from the fortified food) and elderly people (risk of insufficient intake of certain minerals).
Tab. 7.1 Notified cases of most important alimentary affections in 1994–2003 (number of cases/100,000 population)
Diagnosis/Year |
1994 |
1995 |
1996 |
1997 |
1998 |
1999 |
2000 |
2001 |
2002 |
2003 |
Salmonellosis |
491 |
518 |
466 |
386 |
493 |
434 |
389 |
326 |
274 |
263 |
Shigellosis |
17 |
16 |
8 |
6 |
5 |
5 |
5 |
3 |
3 |
4 |
Enteral infections caused |
20 |
21 |
28 |
20 |
19 |
18 |
21 |
20 |
26 |
23 |
Campylobacteriosis |
22 |
29 |
25 |
37 |
54 |
95 |
163 |
210 |
227 |
196 |
Alimentary intoxication |
4 |
9 |
6 |
3 |
5 |
5 |
11 |
7 |
3 |
1 |
Viral gastroenteritis |
2 |
2 |
8 |
5 |
9 |
8 |
12 |
11 |
23 |
21 |
Infectious gastroenteritis |
12 |
12 |
13 |
10 |
6 |
12 |
13 |
13 |
14 |
16 |
Tab. 7.2 Recommended foodstuff doses (servings /person/day) for selected population groupsa
Population group |
Age |
Body weight |
Cereals |
Vegetable |
Fruit |
Milk |
Protein |
Other |
Energy |
Children |
4–6 |
15 |
3 |
3 |
2 |
3 |
2 |
* |
7,047 |
Male, adult |
> 18 |
70 |
6 |
5 |
4 |
3 |
3 |
* |
11,996 |
Female, adult |
> 18 |
58 |
4 |
4 |
3 |
3 |
1 |
* |
7,988 |
Female pregn./nurs. |
> 18 |
58 |
5 |
4 |
3 |
3 |
2 |
* |
9,787 |
Seniors |
> 60 |
64 |
3 |
3 |
2 |
2 |
1 |
* |
5,987 |
* This means temperance in fats, oils, sugar and sweets consumption: 15 g added fats, 10 g added sugar and 300 mL beverages were used for calculation.
Remarks:
a Literature used: see Chapter 14.
b Energy value of the model without calculating added fats, sugar, sweets
and beverages. Energy value was computed by the sum of weighted means of
energy values for particular foodstuff groups calculated according to the
real food availability ratio in CZ in 1997
Model of recommended food doses in CZ used for evaluation of exposure to contaminants
For estimation of the model exposure the values in parenthesis were used.
Tab. 7.3 Estimate of population exposure to chemicals from food, 2003 (according to the consumer food basket)
Compound |
% of exposure limit |
Type of exp. limit |
Compound |
% of exposure limit |
Type of exp. limit |
Manganese |
36.0 |
RfD |
Nickel |
8.0 |
RfD |
Chromium |
24.0 |
RfD |
Lead |
6.0 |
PTWI |
Cadmium |
19.1 |
PTWI |
Aluminium |
4.0 |
PTWI |
Nitrites |
19.0 |
ADI |
Arsenic (inorganic) |
3.5 |
PTWI |
Iron |
19.0 |
PMTDI |
Copper |
3.0 |
PMTDI |
Nitrates |
16.0 |
ADI |
Hexachlorobenzene |
2.8 |
TDI |
Zinc |
16.0 |
PMTDI |
Mercury |
1.3 |
PTWI |
Selenium |
14.0 |
RfD |
DDTs |
0.2 |
PTDI |
PCBs |
8.7 |
TDI |
|
|
|
Tab. 7.4 Estimate of population exposure to benefit elements from food, 2003 (according to the consumer food basket)
Element |
% of recommended intake |
Element |
% of recommended intake |
Nickel |
275 |
Copper |
93** |
Phosphor |
175 |
Calcium |
86 |
Iodine |
153* |
Kalium |
81 |
Chromium |
133 |
Natrium |
78*** |
Selenium |
127** |
Magnesium |
73 |
Zinc |
111** |
Iron |
70 |
Manganese |
101 |
|
|
* in case of iodinated salt usage
** % of normative minimum
*** % of upper limit of intake