Occurrence data

HAs have been issued for bromacil, diuron, and fluometuron no occurrence data are available for tebuthiuron or terbacd (295). Chloroxuron [1982-47-4] fenuronTCA [4482-55-7] andnorea [18530-56-8] also are urea herbicides. 

EPA must first make determinations about which contaminants to regulate. These determinations are based on health risks and the likelihood that the contaminant occurs in public water systems at levels of concern. The National Drinking Water Contaminant Candidate List (CCL), published March 2, 1998, lists contaminants that (1) are not already regulated under SDWA (2) may have adverse health effects (3) are known or anticipated to occur in public water systems and (4) may require regulations under SDWA. Contaminants on the CCL are divided into priorities for regulation, health research and occurrence data collection. 

Table 2 APIs environmental occurrence data, from 2006 until nowadays...

There are some data on PFGS and PFGA in fish and water from European countries. However, there is a general lack of occurrence data for most foodstuffs. This evaluation, based on food consumption patterns of the EU countries Italy, The Netherlands, Sweden, and the UK, must be regarded as provisional while waiting for the necessary food monitoring results to be gathered. 

Timelines do not have to end at the time of the occurrence or incident. Sometimes post occurrence data can be valuable. Often, it is important to understand how the emergency response actions affected the ultimate outcome of the occurrence. This type of data can be used to improve emergency response actions in the future. 

Occurrence data the concentrations of the chemical in the foods of concern including, if relevant, the frequency of occurrence. 

Petrovic, M., E. Eljarrat, MJ. Lopez de Alda, et al. 2004. Endocrine disrupting compounds and other emerging contaminants in the environment A survey on new monitoring strategies and occurrence data. Anal. Bioanal. Chem. 378 549-562. 

Jorgensen, K. (2005). Occurrence of ochratoxin A in commodities and processes food - A review of EU occurrence data. Food Add. Cont. Suppl., 1, 26-30. 

Westrick J. J., Mills J. W., and Thomas R. F. (1983) The Ground Water Supply Survey Summary of Volatile Organic Contaminant Occurrence Data. US EPA, Office of Drinking Water, Cincinnati, OH. 

The 1996 Amendments further require EPA to establish a mechanism to identify and select new contaminants, as well as specific efforts to establish criteria for arsenic, sulfates, radon, and disinfection by-products. The SDWA required EPA to establish a list of contaminants every five years that are known or anticipated to occur in public water systems and may require further investigation and possible regulation under SDWA. The list is divided into those materials that are candidates for additional research, those that need additional occurrence data, and those that are priorities for consideration in rulemaking. The EPA then must prioritize the critical substances in each category and develop a plan of action for making regulatory decision for the most appropriate candidates. 

In order to determine the mixture risk quotients for each of the study sites on each sampUng occasion, data were obtained from the literature on the ecotoxicity of the parent compounds to fish and daphnids. Experimental ecotoxicity data were also obtained for the transformation products where available. In instances where experimental data were not available for the transformation products, estimates of ecotoxicity were obtained using the predictive approach of Escher which is described in the previous section. Experimental and predicted ecotoxicity data were then used alongside the monitoring data to calculate mixture risk quotients for each of the sampHng sites on each sampling occasion for fish and daphnids. The mixture risk quotients were calculated a) using only the parent compound occurrence data and b) the parent compound and transformation product data. 

National Occurrence Data Base and the Unregulated Contaminant Monitoring Rule Prevention approaches... 

SDWA has provisions that provide for the collection, organization and sharing of occurrence data on contaminants of potential concern. The National Drinking Water... 

The occurrence data used in the calculation of dietary exposure estimates were as follows for meat and meat products, 0.1 mg/kg for both chlorite and chlorate for seafood and freshwater fish, 0.01 mg chlorite/kg and 0.1 mg chlorate/ kg for fruits and vegetables, 0.01 mg chlorite/kg for all fruits and vegetables except for leafy vegetables (0.23 mg chlorite/kg) and 0.01 mg chlorate/kg. 

The Committee noted that the occurrence data submitted for chlorite and chlorate, determined using good manufacturing practice for ASC-treated foods, were sufficient to be used in the assessment. These occurrence data were used with national diet data for EU countries and the 13 GEMS/Food Consumption Cluster Diets in a dietary exposure scenario whereby all treated food categories consumed contained chlorite and chlorate at the maximum residual concentrations. 

Natural occurrence data reported in a private communication to Flavor and Extract Manufacturers Association (2006). 

Recoveries of AFL in the different substrates sometimes affect the occurrence data more than the sensitivity of the quantification method. If the... 

Brazil submitted occurrence data for 329 individual results of Brazil nut lots to be exported to the EU (35 lots) and other countries (294 lots). The data refer to in-shell (processed and unprocessed) and shelled Brazil nuts, and in all cases only the edible portion (kernels) was analysed. AFL concentrations were reported as below the LOD for 85% of the exported nut lots. The most common LOD reported was 0.5-0.6 pg/kg for AFBi and 0.3-0.5 pg/kg for other AFL (AFBa, AFGi and AFG2). Average concentration levels from Brazil nut lots were around 8.5 pg/kg for AFBi and 20 pg/kg for AFT (as shown in Table 4 below). The legal regulatory limit in Brazil is 30 pg/kg for AFT for Brazil nut lots sold in the Brazilian market. 

For maize, a publication review on AFT occurrence data by Williams et al. (2004) reported concentrations 10 times higher than those described in Table 7 (around 33 pg/kg on average in Bangladesh). JECFA also reported a mean level of 35 pg/kg in maize from Brazil, with 51% of data above the LOD. AFBi in barley-based food was also reported at an average level of 4.1 pg/kg in the Republic of Korea (Park et al., 2004). 

The EFSA opinion assessed the infiuence of changes to the MLs (4, 8 and 10 pg/kg) for aimonds, hazeinuts and pistachios on the overaii dietary exposure to AFL. in the EFSA opinion, dietary exposure estimates were based on food consumption data from individuai dietary records for nuts from representative Member States and on food consumption data from the GEMS/Food Consumption Ciuster Diets database of the Worid Heaith Organization (2006) for all other foods. Mean AFT occurrence data used in its caicuiations were those reported in the EFSA opinion. 

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