Duplicate Diet Research Articles

Comparison of complementary feeding strategies to meet zinc requirements of older breastfed infants

The low zinc intake from human milk at ∼6 mo of age predicts the dependence on complementary foods (CF) to meet the zinc requirements of older breastfed-only infants. The objective of this study was to compare major variables of zinc homeostasis and zinc status in 9-mo-old breastfed infants who were randomly assigned to different complementary food regimens. Forty-five exclusively breastfed 5-mo-old infants were randomly assigned to receive commercially available pureed meats, iron-and-zinc-fortified infant cereal (IZFC), or whole-grain, iron-only-fortified infant cereal (IFC) as the first and primary CF until completion of zinc metabolic studies between 9 and 10 mo of age. A zinc stable-isotope methodology was used to measure the fractional absorption of zinc (FAZ) in human milk and CF by dual-isotope ratios in urine. Calculated variables included the dietary intake from duplicate diets and 4-d test weighing, the total absorbed zinc (TAZ) from FAZ × diet zinc, and the exchangeable zinc pool size (EZP) from isotope enrichment in urine. Mean daily zinc intakes were significantly greater for the meat and IZFC groups than for the IFC group (P < 0.001); only intakes in meat and IZFC groups met estimated average requirements. Mean (±SEM) TAZ amounts were 0.80 ± 0.08, 0.71 ± 0.09, and 0.52 ± 0.05 mg/d for the meat, IZFC, and IFC groups, respectively (P = 0.027). Zinc from human milk contributed <25% of TAZ for all groups. The EZP correlated with both zinc intake (r = 0.43, P < 0.01) and TAZ (r = 0.54, P < 0.001). Zinc requirements for older breastfed-only infants are unlikely to be met without the regular consumption of either meats or zinc-fortified foods.

Quantifying children's aggregate (dietary and residential) exposure and dose to permethrin: application and evaluation of EPA's probabilistic SHEDS-Multimedia model

Reliable, evaluated human exposure and dose models are important for understanding the health risks from chemicals. A case study focusing on permethrin was conducted because of this insecticide's widespread use and potential health effects. SHEDS-Multimedia was applied to estimate US population permethrin exposures for 3- to 5-year-old children from residential, dietary, and combined exposure routes, using available dietary consumption data, food residue data, residential concentrations, and exposure factors. Sensitivity and uncertainty analyses were conducted to identify key factors, pathways, and research needs. Model evaluation was conducted using duplicate diet data and biomonitoring data from multiple field studies, and comparison to other models. Key exposure variables were consumption of spinach, lettuce, and cabbage; surface-to-skin transfer efficiency; hand mouthing frequency; fraction of hand mouthed; saliva removal efficiency; fraction of house treated; and usage frequency. For children in households using residential permethrin, the non-dietary exposure route was most important, and when all households were included, dietary exposure dominated. SHEDS-Multimedia model estimates compared well to real-world measurements data; this exposure assessment tool can enhance human health risk assessments and inform children's health research. The case study provides insights into children's aggregate exposures to permethrin and lays the foundation for a future cumulative pyrethroid pesticides risk assessment.

A matrix effect-free method for reliable quantification of perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids at low parts per trillion levels in dietary samples

In recent exposure modeling studies diet has been identified as the dominant pathway of human exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). However, the paucity of highly sensitive and accurate analytical data to support these studies means that their conclusions are open to question. Here a novel matrix effect-free method is described for ultra-trace analysis of perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids in dietary samples of varied composition. The method employs ion pair extraction of the analytes into methyl tert-butyl ether and subsequent solid phase extraction clean-up on Florisil and graphitized carbon. The target compounds are separated and detected using ultra performance liquid chromatography coupled to tandem mass spectrometry. Special care was taken to avoid procedural blank contamination and potential contamination sources were elucidated. The performance of the method was validated for five different food test matrices including a duplicate diet sample. Method detection limits in the low to sub pgg−1 range were obtained for all target analytes, which is 5–100 times more sensitive than previously reported for duplicate diet samples. Total method recoveries were consistently between 50 and 80% for all analytes in all tested food matrices and effects of co-extracted matrix constituents on ionization of the target compounds were found to be negligible. The precision of the method (defined as percentage relative standard deviation) at concentrations close to the respective method limits of quantification was <15% for all analytes. Accurate quantification at ultra-trace levels was demonstrated by laboratory control spike experiments. For the first time the presence of long-chain PFCAs in duplicate diet samples is reported. The method presented here can thus support an improved assessment of human exposure from dietary intake for a range of PFCA and PFSA homologues. Re-analysis of duplicate diet samples, which had been analyzed earlier using another analytical methodology, indicated that dietary intake of PFOA and PFOS may previously have been overestimated.

Community duplicate diet methodology: A new tool for estimating dietary exposures to pesticides

An observational field study was conducted to assess the feasibility of a community duplicate diet collection method; a dietary monitoring tool that is population-based. The purpose was to establish an alternative procedure to duplicate diet sampling that would be more efficient for a large, defined population, e.g., in the National Children's Study (NCS). Questionnaire data and food samples were collected in a residence so as not to lose the important component of storage, preparation, and handling in a contaminated microenvironment. The participants included nine Hispanic women of child bearing age living in Apopka, FL, USA. Foods highly consumed by Hispanic women were identified based on national food frequency questionnaires and prioritized by permethrin residue concentrations as measured for the Pesticide Data Program. Participants filled out questionnaires to determine if highly consumed foods were commonly eaten by them and to assess the collection protocol for the food samples. Measureable levels of permethrin were found in 54% of the samples. Questionnaire responses indicated that the collection of the community duplicate diet was feasible for a defined population.

Micronutrient Daily Intake of Elementary School Children in Bandung as Determined by Using NAA and AAS Methods

Micronutrients in human diet are known to be among the most essential sources of nutrition, that required by the human body in small amount to maintain normal physiological function. Micronutrient malnutrition (MNM) is widespread all over the world, mostly in the developing country, where young children tend to be the most at risk of developing micronutrient deficiencies. In Indonesia, data of micronutrient status of children is limited. Therefore, the assessment of micronutrient intake of young children is needed to carry out. Food samples were taken by duplicate diet method of 19 elementary school children in Bandung and were analyzed using neutron activation analysis and atomic absorption spectrophotometry. Quality control of data analysis was assessed using SRM NIST 1548a Typical Diet. The result was giving the average daily intake of Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Se and Zn were 228, 0.15, 0.57, 9.3, 929, 106, 2,1, 2314, 0.022 and 4.6 mg/day respectively and gives 22, 527, 86, 111, 17, 54, 116, 49 and 63% of Recommended Dietary Allowance (RDA) values. Its generally concluded that these children are still lack of micronutrient intake, and many of them were below their recommended dietary allowances. These result were expected could be used as baseline data and reference to encourage government and related institution in making policies for public health improvement and micronutrient malnutrition solution as well. Received: 20 November 2010; Revised: 03 April 2011; Accepted: 04 April 2011

Dietary Intake of Metals by the Population of Tarragona County (Catalonia, Spain): Results from a Duplicate Diet Study

The daily intakes of arsenic (As), beryllium, cadmium (Cd), cobalt, chromium, copper, mercury (Hg), manganese, nickel, lead (Pb), antimony, tin, thallium, uranium, vanadium, and zinc by an adult population living in Tarragona County (Catalonia, Spain) were determined by the duplicate diet method with a 10-day sampling period. Duplicate diet samples, prepared as per consumption, were collected during September 2010 in 20 restaurants offering a variety of daily menus (breakfast, lunch, and dinner). A total of 200 composite samples, corresponding to 600 individual samples, were prepared for trace elements analyses, which were carried out by inductively coupled plasma mass spectrometry. The results were compared with data from previous total diet studies (TDS) recently performed in the same geographical area. Notable differences in the intake of the toxic elements As, Cd, Hg, and Pb were found depending on the method used. It is concluded that both the duplicate diet method and the TDS may provide important and useful information to estimate human exposure to metals through the diet and their derived health risks. However, for comparison between surveys or for establishing temporal trends in the intake of metals, it seems to be recommendable to use always the same method. Notwithstanding, if the interest is only to know whether the intake of a certain element is below the tolerable intake, both methods are useful.

Dietary supply of selenium for adolescents in three residential care orphanages in Southern Ghana

Adolescents require optimum dietary supply of the essential trace mineral selenium (Se); however the absence of reliable and accurate data on the dietary supply of selenium for the adolescent population in Ghanaian residential care orphanages have made it difficult for public health nutritionists to assess the adequacy of the dietary supply. The dietary supply of selenium for adolescents (12–15 years) in three residential care orphanages, (Osu, Tutu-Akwapim and Teshie), in Southern Ghana have been evaluated by sampling their 24-h duplicate diets (including water) for 7-consecutive days using the duplicate diet sampling technique. The mass fraction of selenium in the blended lyophilized homogenates of duplicate diets was determined by radiochemical neutron activation analysis (RNAA). The validity of the RNAA method for selenium determination was checked by analyses of NIST SRM 1548a (Typical diet). The chemical yield of the radiochemical separation was determined by spectrophotometry. The average mass fractions of selenium in the blended lyophilized 24-hour duplicate diets for Osu, Tutu-Akwapim and Teshie were; 165 ± 61 [117.2–285.2], 203 ± 68 [110.5–304.9] and 250 ± 92 [128.8–408.0] ng Se g − 1 lyophilized matter respectively. The average dietary supply of Se were, 57.6 ± 17.3 [42.2–88.4], 82.0 ± 30.7 [44.3–136.2] and 91.7 ± 44.2 [46.0–153.4] μg Se day − 1 for Osu, Tutu-Akwapim and Teshie orphanages respectively. The data generated will help public health nutritionists in the provision of dietary advice and nutritional support for the studied orphanages, as well as other orphanages. The data will also help in the planning of institutional diets.

Daily dietary intake of iodine by adolescents in three residential care orphanages in southern Ghana

The essential mineral iodine plays an important role in early growth, cellular metabolism and the proper development of the brain; data on the daily dietary intake of iodine by adolescents in residential care orphanages in Ghana are scarce. Consequently, the adequacy of their dietary intake of iodine cannot be assessed. The dietary intake of iodine by adolescents in three residential care orphanages (Osu, Tutu-Akwapim and Teshie) in Southern Ghana have been evaluated by sampling the 24 h duplicate diets of the adolescents for 7-consecutive days using the duplicate diet sampling technique. The iodine content was determined by radiochemical neutron activation analysis (RNAA). Mean daily iodine content in the blended lyophilized 24 h duplicate diets were 287 ± 95, 286 ± 109 and 961 ± 142 ng g-1 lyophilized matter for Osu, Tutu-Akwapim and Teshie orphanages, respectively. The average iodine intake by the adolescents were 102 ± 25, 115 ± 25 and 340 ± 117 μg day-1 for Osu, Tutu-Akwapim and Teshie orphanages, respectively. The intake of iodine by Osu and Tutu adolescents though lower than the recommended daily allowance (RDA) of 150 μg day-1, are within the normal 100 to 150 µg day-1 iodine intake common in non-iodine deficient countries of the world. Key words: Ghana, adolescents, dietary intake, duplicate diet, iodine, orphanage.

Selenium exposure in subjects living in areas with high selenium concentrated drinking water: Results of a French integrated exposure assessment survey

BackgroundSelenium is an essential element which can be toxic if ingested in excessive quantities. The main human exposure is food. In addition, intake may be boosted by consumption drinking water containing unusual high selenium concentration. ObjectiveWe measured the individual selenium level of people exposed to selenium concentration in drinking water greater than the maximum recommended limit which is 10μg/L. MethodsWe carried out a prospective cohort study on 80 adults (40 exposed subjects i.e. living in the involved area and 40 non-exposed ones i.e. living elsewhere) in western France. We used three different approaches: (1) direct measurement of ingested selenium by the duplicate portion method, (2) dietary reconstitution with a food frequency questionnaire (FFQ) and (3) evaluation of the individual selenium status by measuring the selenium content in toenail clippings. Analyses were performed by inductively coupled plasma-mass spectrometry. The association between toenail selenium concentration and area of residence was analyzed using linear regression with repeated measurements. ResultsWe estimated selenium intake from FFQ at 64±14μg/day for exposed subjects as opposed to 52±14μg/day for the non-exposed ones. On the basis of 305 duplicate diet samples, average intake was estimated at 64±26μg/day for exposed subjects. Area of residence (p=0.0030) and smoking (p=0.0054) were independently associated with toenail selenium concentration. ConclusionWhatever method used for estimating selenium intake, the selenium level in this studied area with high selenium concentrated drinking water is much lower than in seleniferous areas.

Dietary intake of mercury by children and adults in Jinhu area of China

Dietary intakes of mercury by children and adults in Jinhu area of China were determined using a duplicate diet approach. A total of 176 duplicate diet portions were collected from 60 individuals in November and December of 2007. Mercury levels in duplicate samples were measured by atomic fluorescence spectrometry. The daily mercury intakes (median and range) from consumption days without fish or shellfish for children and adults were 0.13 (0.05-0.78) μg(kg(bw))(-1) day(-1) and 0.07 (0.04-0.18) μg(kg(bw))(-1) day(-1), respectively, which were significantly lower than those from consumption days with fish or shellfish for both children and adults whose daily intakes (median and range) were 0.16 (0.11-0.84) μg(kg(bw))(-1) day(-1) and 0.09 (0.05-0.46) μg(kg(bw))(-1) day(-1), respectively. The exposure level of children was significantly higher than that of adults. The 50th and 99th percentile of the usual mercury intake from all consumption days for children were 0.14 and 0.22 μg(kg(bw))(-1) day(-1) and for adults were 0.09 and 0.14 μg(kg(bw))(-1) day(-1), where the between-person variance in dietary mercury intake for children and adults were 0.038 and 0.036, respectively. Comparing with the provisional tolerable weekly intake (PTWI) divided into daily intake (PTDI) of 0.57 μg(kg(bw))(-1) day(-1), it is concluded that the average daily intakes and the usual intakes to mercury can be considered safe for both children and adults in Jinhu area by the duplicate diet study. But the maximum daily intakes for children exceeding the PTDI deserve a close attention.

Complementary food (CF) choices are critical to meet physiologic requirements for zinc (Zn)

Background Breastfed infants are dependent on CF to meet Zn physiologic requirements (PR) after 6 mo of age. Objective Compare Zn homeostasis in exclusively breastfed infants (EBFI) randomized to different CF regimens emphasizing meat or fortified infant cereals. Methods 42 EBFI were randomized to 1 of 3 CF regimens to start at ~6 mo: Fe-fortified cereal (IFC), Fe/Zn-fortified cereal (IZFC), or meat (M); all infants were allowed fruits/vegetables ad lib. Between 9–10 mo, Zn stable isotopes were administered orally with human milk (HM) and CF; a 3rd isotope was administered IV. Total dietary Zn intake (TDZ) was determined from duplicate diets and 3-d test weighing. Fractional absorption of Zn (FAZ) was measured by dual isotope ratios in urine. Total absorbed Zn (TAZ) = FAZ x TDZ. Percent of infants with TAZ ≥ PR was also determined for each group. Results *: IFC (n=13) IZFC (n=14) M (n=12) Diet Zn (HM)† 0.31 ± 0.04 0.26 ± 0.04 0.24 ± 0.05 Diet Zn (CF)† 1.42 ± 0.14a 3.12 ± 0.19b 3.31 ± 0.31b AZ (HM)† 0.16 ± 0.03 0.11 ± 0.02 0.09 ± 0.03 AZ (CF)† 0.36 ± 0.05a 0.60 ± 0.09a,b 0.71 ± 0.08b TAZ† 0.52 ± 0.05a 0.71 ± 0.09a,b 0.80 ± 0.08b % meeting PR 0 29 46 *Mean ± SE, different superscripts within row indicate sig diff (ANOVA, P<0.05); † mg/d Conclusions These data confirm that HM provides modest contribution to meeting Zn requirements at this age. Absorption efficiency does not compensate for low Zn intake of unfortified cereal to meet PR. Older breastfed infants are thus vulnerable to Zn deficiency unless consuming fortified or naturally rich complementary foods. Support: The Beef Checkoff, NCBA and NIH K24DK083772.

Estimation of mineral and trace element intake in vegans living in Japan by chemical analysis of duplicate diets

Thirty-six daily duplicate diet samples were collected from 12 healthy female Japanese vegans and sodium, potassium, calcium, magnesium, phosphorus, iron, zinc, copper, manganese, iodine, selenium, chromium and molybdenum in the diets were measured to estimate mineral and trace element intake by Japanese vegans. Significantly higher intake of potassium, magnesium, phosphorus, iron, copper, manganese and molybdenum was observed in vegans than in general Japanese women, but no difference was observed in sodium, iodine, selenium and chromium intake. Vegan calcium intake tended to be low compared to that of general women but the difference was not significant. Since high potassium, magnesium and iron intakes cannot be achieved by general Japanese diets and high intake of potassium and magnesium may prevent hyperextension and cardiovascular disease in vegans, there are few problems with Japanese vegan diets regarding mineral and trace element intake, except for calcium intake, which is low as it is in the general Japanese people.

Multimedia and Multipathway Aggregate Exposure Assessment for Polycyclic Aromatic Hydrocarbons to the Inhabitant in Taean County After Hebei-Spirit Oil Spill

PP-30-115 Background/Aims: Two years after the Hebei-Spirit oil spill occurred, aggregate exposure assessment to polycyclic aromatic hydrocarbons (PAHs) including alkylated PAHs was conducted for the inhabitants in Taean county, multimedia and multipathway aggregate exposure assessment for PAHs were conducted for 45 nonsmoking residents in the following 2 age groups; children (11–13 years), adult (>20). Methods: A total of 34 PAHs were analyzed in several types of samples for inhalation exposure route (ambient air), ingestion exposure route (soil, house dust, 24-hour duplicate diet, fish, and shellfish collected near the spill area), and dermal exposure route (soil and floor dust). Results: PAHs concentrations ranged from 0.27 to 8.26 ng/m3 for air, 0.72 to 69.37 ng/g for food, 1.39 to 49.90 ng/g for fish and shellfish, 0.11 to 80.66 ng/m2 for floor dust, and 0.36 to 55.32 ng/g for soil. The average daily PAHs exposures of children and adult were 126.89 (geometric mean: 99.38) ng/kg/d and 135.79 (43.92) ng/kg/d, respectively. Conclusion: The exposure levels were lower than those (15 PAHs) obtained in other urban and rural areas of Korea. Food intake was found as a major exposure route (>99%). Fish and shellfish caught from Taean county contributed to only 10% of 34 PAHs exposure through food intake. It is confirmed that the exposure level to PAHs, including alkylated PAH, was recovered to the baseline condition within the 2 years after the Hebei-Spirit oil spill.

Dietary intake of lead and cadmium by children and adults – Result calculated from dietary recall and available lead/cadmium level in food in comparison to result from food duplicate diet method

The dietary intakes of lead and cadmium by 30 children and 30 adults living in Jinhu area in China were determined by the duplicate method with a 3-day sampling period. Dietary recall and available lead/cadmium level in food were also used to calculate dietary intakes. Lead intakes based on duplicate method were 15.66μg(kg(bw))(-1)week(-1) for children and 8.83μg(kg(bw))(-1)week(-1) for adults. Cadmium intakes were 2.07μg(kg(bw))(-1)week(-1) for children and 1.49μg(kg(bw))(-1)week(-1) for adult. The results from the dietary record method were as follows: lead intakes were 11.84μg(kg(bw))(-1)week(-1) for children and 7.70μg(kg(bw))(-1)week(-1) for adult. Cadmium intakes were 2.20μg(kg(bw))(-1)week(-1) for children and 1.44μg(kg(bw))(-1)week(-1) for adults. Children's dietary intakes were higher than those of adults'. The results of the dietary intakes calculated from two methods did not have significant difference. Compared to the FAO/WHO PTWIs for lead and cadmium, the average lead and cadmium dietary intakes are all below PTWIs. It was concluded that dietary record method can give comparatively accurate result for lead and cadmium dietary intakes compared with duplicate method. The average lead and cadmium dietary intakes for children and adults in Jinhu area are considered safe. However, the high level of dietary lead and cadmium intakes of children in this area deserves our attention.

Dietary intake of arsenic by children and adults from Jinhu area of China

The aim of this study was to estimate the dietary intake of arsenic (As) by children and adults from Jinhu area of China. A duplicate diet approach was used to collect diet samples in November and December 2007. The As content was measured by hydride generation atomic fluorescence spectrometry. The As intakes (median) for different group were: children: 0.6 µg kg−1 bw day−1 or 6.7 µg kg−1 bw week−1; adults: 0.5 µg kg −1 bw day−1 or 3.8 µg kg −1 bw week−1, none of which exceeded the provisional tolerable weekly intake (PTWI) of 15 µg kg −1 bw week−1 for As proposed by the World Health Organization (WHO). The median and maximum of the children group amounted to 44.7% and 125.3% of the PTWI; the values for adults were 25.3% and 118.7%, respectively. There were 3.3% of children whose weekly As intake exceeded the PTWI, and there were 6.7% of adults whose weekly As intake exceeded the PTWI. It is concluded that dietary As intake was safe for most people in Jinhu area, but the high dietary As intake for a minority of people in this area deserves attention.

Assessment of the dietary habits and polycyclic aromatic hydrocarbon exposure in primary school children

Thirty Italian children, 7–9 year aged, living in Naples were investigated on their dietary habits and on polycyclic aromatic hydrocarbon (PAH) exposure by a food diary-questionnaire and one week duplicate diet sample analyses. Daily total food consumption mean value was 632 ± 215 g day−1, median value 613 g day−1. The daily energy intake and the diet composition meanly agreed with the official guidelines for the Italian children. Sixteen PAHs were simultaneously detected and, according to the European Food Safety Authority (EFSA) approach, benzo[a]pyrene; benzo[a]pyrene + chrysene (PAH2); PAH2 + benz[a]anthracene + benzo[b]fluoranthene (PAH4); PAH4 + benzo[k]fluoranthene + benzo[ghi]perylene + dibenz[a, h]anthracene + indeno[1,2,3-cd]pyrene (PAH8) were considered in evaluating the children's dietary exposure to PAHs. The benzo[a]pyrene (BaP) median concentrations in foods varied from 0.06 to 0.33 µg kg−1. Only three samples of cooked foods (one fish and two meat samples) exceeded legal limits fixed by the European Union for BaP. Daily median intakes of benzo[a]pyrene, PAH2, PAH4, and PAH8 were 153; 318; 990; 1776 ng day−1; their median exposure values were 5; 10; 28; 54 ng kg−1 bw day−1. The Margins of Exposure (MOEs) in median consumers agreed with the EFSA safety values except for PAH8.

Intake of iron, zinc and iodine in 28 Ethiopian children living in Wonji Shoa Sugar Estate, assessed by duplicate portion technique

In the present study, duplicate diets (four-day survey) of 28 Ethiopian children were analysed for iron, zinc and iodine. The mothers of the children filled out a food frequency questionnaire describing general intake of local food ingredients. The average daily intake of zinc was found to be 5.7 ± 5.2 mg, while the daily intake of iron and iodine was 52 ± 43 mg and 0.13 ± 0.10 mg, respectively. Most of the investigated children had an adequate nutrient intake of zinc and iodine, while the intake of iron was high compared to international recommendations. There was a great individual variation in intake of these trace elements, and even though the mean and median values were above or in the range of the requirement, some children had a too low intake of zinc and iodine. The iron intake varied the most, and was generally high. The diet was cereal based and contained little fruit and food of animal origin which may reduce the availability of iron and zinc. Key words: Trace elements, nutrition, low-income, Africa, enjera, teff, cereals, iron, zinc, iodine intake, Ethiopian children.

For good measure: Origins and prospects of exposure science (2007 Wesolowski Award Lecture)

Measurement is the foundation of exposure science. Associations between illness and environmental agents have been observed for millennia, but the ability to quantify exposure and dose has been possible only in the last century. Improved means of measurement and refined concepts of who, what, when, where, and why to measure have been the seminal contributions of exposure science to the study of disease causation and prevention. This paper examines critical advancements in exposure assessment associated with workplace health and safety, and the groundbreaking work of the US Public Health Service. Many of the key concepts of modern exposure science have their origin in these early studies. Occupational hygiene scientists have conducted receptor-based exposure analyses for more than 80 years, evaluating indoor air, defining microenvironments, and developing personal sampling techniques. Biological monitoring of community populations including children, dermal exposure monitoring, duplicate diet studies, and multi-pathway, aggregate exposure assessments can be traced to early public health studies. As we look to the future, we see that new technologies and techniques are expanding the scope of exposure science dramatically. We need to ensure that the highest of scientific standards are maintained, make a greater effort to include occupational hygiene scientists, microbiologists, and behavioral scientists in the field, and promote new sources of training and research support. Exposure science has a critical role to play in the prevention strategy that is central to public health.

Validation of a database on acrylamide for use in epidemiological studies

Acrylamide, a probable human carcinogen, was detected in various heat-treated foods such as French fries and potato crisps. Recently, positive associations have been found between dietary acrylamide intakes, as estimated with a food frequency questionnaire using an acrylamide database, and cancer risk in some epidemiological studies. As acrylamide levels vary considerably within the same type of foods, a validation study was performed to investigate whether use of an acrylamide food database containing calculated mean acrylamide content, based on extensive sampling and chemical analysis of Dutch foods (several samples per food), can classify subjects with respect to true acrylamide intake. We used the data from a 24-h duplicate diet study. The acrylamide content of 39 Dutch 24-h duplicate diets collected in 2004 was estimated using the mean acrylamide levels of foods available from the database and the menu list, on which the participants of the duplicate diet study had listed the amounts of individual foods and drinks in household units. Next, the acrylamide content of the total duplicate diets was analytically measured and correlated to the estimated acrylamide contents. The Spearman's correlation coefficient between chemically determined acrylamide content and the calculated acrylamide content of the duplicate diets was 0.82 (P<0.001). This study indicates that it is possible to classify subjects with respect to acrylamide intake if mean instead of actual content of each food is applied. The database can therefore be applied in epidemiological studies on acrylamide intake and cancer risk, such as the Netherlands Cohort Study on Diet and Cancer.

Pyrethroid and Organophosphorus Pesticides in Composite Diet Samples from Atlanta, USA Adults

Four pyrethroid (permethrin, cyfluthrin, cypermethrin, deltamethrin) and 3 organophosphorus (chlorpyrifos, diazinon, malathion) pesticides were measured in 4 days of 24 h duplicate diet samples collected from 12 Atlanta adults over two cycles (2005-2006). Samples were composited into 9 categories, by food type, to evaluate their contribution to daily intakes. The resulting 437 samples were analyzed using a multiresidue method using liquid-liquid and solid-phase extraction followed by quantification via gas chromatograph with electron-capture detection. Total daily intakes (mg/kg-d) were calculated by summing the mass of a pesticide in all composites collected that day and dividing by body weight. Chlorpyrifos, diazinon, and cypermethrin in were detected in a range of composite types at frequencies > or =30%, whereas other pesticides were detected at lower frequencies. Concentrations ranged from the detection limits (0.38-0.88 ng/g) to several hundred ng/g, exceeding U.S. tolerances in a few cases. We also detected pesticides in some foods labeled organic. Total daily intakes were below the U.S. Environmental Protection Agency's oral reference doses, except in 6% of cases when the organophosphorus concentrations were summed. Results show frequent dietary exposure of our participants to the target pesticides from a range of food types.