Dietary exposure process

The registrant may submit residue data on any number of processed fractions. Table 1 of the 860 Series just defines what the EPA is required. A registrant may be wise to take a proactive approach and collect residue data on additional processed commodities for use in dietary exposure assessments. 

The FDA and EPA recognize that the diets of infants and children may differ substantially from those of adults and that they consume more food for their size than adults. As a result, they may be exposed to proportionately more residues. The FDA and EPA address these differences by combining survey information on food consumption by nursing infants, non-nursing infants, and children with data on residues to estimate their dietary exposure. The FDA and EPA also use this process to estimate exposure for other age groups, as well as several different ethnic groups and regional populations. 

Food might become contaminated during production processes and/or cooking due to contact with treated cookware that can release PFCs. However, it must be stressed that the data in general are insufficient to allow for a general evaluation of the contribution of food contact materials to total dietary exposure to PFCs. 

Jinzu Valley, Japan. One of the most infamous cases of contaminated land and health occurred in Japan and the effects were most prominent immediately after the Second World War. Around the end of the 19th century, soils in the Jinzu River basin, part of the Toyama prefecture, became contaminated with cadmium as a result of activities upstream at the Kamioka mines. The main activity at this mine was the mining and processing of zinc (cadmium is often associated with zinc ores) with the result that wastewater rich in heavy metals was discharged into the Jinzu River. Contaminants from this industry moved down-stream and caused contamination of soils in paddy fields as a result of abstraction of river water into fields in order to cultivate the local rice crop. Under favourable conditions, cadmium can be a fairly mobile heavy metal, particularly in soils with low pH, and increases in soil cadmium can often result in an increase in the uptake of cadmium by plants. This in turn results in an increase in dietary exposure and the consumption of contaminated agricultural crops can be a major pathway of human exposure. 

Based on a maximum mean daily consumption of 960 g of processed foods (cereals, roots and tubers GEMS/Food Consumption Cluster Diet B) by a 60-kg adult and on the assumptions that the enzyme is used at the maximum recommended use level and that all TOS originating from the enzyme preparation remain in the final products, the dietary exposure would be 0.4 mg TOS/kg bw per day. 

Isoamylase Is used for the production of food ingredients from starch. Although at the end of the production processes the enzyme is usually inactivated or removed, the actual levels of the enzyme (active or inactive) in the final food produots are not known. A worst-oase scenario for human dietary exposure can be estimated on the basis of the reoommended use levels and the assumption that all TOS originating from the enzyme preparation are carried over into the final products. To elaborate this scenario, it is assumed that ... 

For this evaluation, the Committee considered new toxicological studies that had become available since the last evaluation these included further studies on developmental toxicity, neurotoxicity, immunotoxicity, nephrotoxicity and geno-toxicity and studies on the mode of action of ochratoxin A in the kidney. The Committee also considered the opinion on ochratoxin A in human food published by the European Food Safety Authority (EFSA) in 2006 (European Food Safety Authority, 2006). New data on analytical methods, sampling protocols and the effects of processing were also considered, together with methods of prevention and control and levels and patterns of food contamination. A new dietary exposure assessment was conducted, and the impact of different MLs for cereals was considered. 

African samples were not used for the dietary exposure assessment because they were targeted samples with fungal contamination. Individual data were not available either from Canada or from the EU. Finally, the Committee decided not to merge individual analytical data from Germany and Japan and to focus for the dietary exposure on the largest data set represented by German analytical results for raw and processed cereals. 

The current estimate of overall dietary exposure to ochratoxin A from cereals, based mainly on European data, is about 8-17 ng/kg bw per week, based on processed cereals, compared with 25 ng/kg bw per week in the previous evaluation, based on raw cereals. The current estimate is well below the PTWI. 

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