Dietary intake of nickel and zinc by young children--results from food duplicate portion measurements in comparison to data calculated from dietary records and available data on levels in food groups

A State-of-the-Science Review on Metal Biomarkers

PURPOSE OF REVIEW

Biomarkers are commonly used in epidemiological studies to assess metals and metalloid exposure and estimate internal dose, as they integrate multiple sources and routes of exposure. Researchers are increasingly using multi-metal panels and innovative statistical methods to understand how exposure to real-world metal mixtures affects human health. Metals have both common and unique sources and routes of exposure, as well as biotransformation and elimination pathways. The development of multi-element analytical technology allows researchers to examine a broad spectrum of metals in their studies; however, their interpretation is complex as they can reflect different windows of exposure and several biomarkers have critical limitations. This review elaborates on more than 500 scientific publications to discuss major sources of exposure, biotransformation and elimination, and biomarkers of exposure and internal dose for 12 metals/metalloids, including 8 non-essential elements (arsenic, barium, cadmium, lead, mercury, nickel, tin, uranium) and 4 essential elements (manganese, molybdenum, selenium, and zinc) commonly used in multi-element analyses.

RECENT FINDINGS

We conclude that not all metal biomarkers are adequate measures of exposure and that understanding the metabolic biotransformation and elimination of metals is key to metal biomarker interpretation. For example, whole blood is a good biomarker of exposure to arsenic, cadmium, lead, mercury, and tin, but it is not a good indicator for barium, nickel, and uranium. For some essential metals, the interpretation of whole blood biomarkers is unclear. Urine is the most commonly used biomarker of exposure across metals but it should not be used to assess lead exposure. Essential metals such as zinc and manganese are tightly regulated by homeostatic processes; thus, elevated levels in urine may reflect body loss and metabolic processes rather than excess exposure. Total urinary arsenic may reflect exposure to both organic and inorganic arsenic, thus, arsenic speciation and adjustment for arsebonetaine are needed in populations with dietary seafood consumption. Hair and nails primarily reflect exposure to organic mercury, except in populations exposed to high levels of inorganic mercury such as in occupational and environmental settings. When selecting biomarkers, it is also critical to consider the exposure window of interest. Most populations are chronically exposed to metals in the low-to-moderate range, yet many biomarkers reflect recent exposures. Toenails are emerging biomarkers in this regard. They are reliable biomarkers of long-term exposure for arsenic, mercury, manganese, and selenium. However, more research is needed to understand the role of nails as a biomarker of exposure to other metals. Similarly, teeth are increasingly used to assess lifelong exposures to several essential and non-essential metals such as lead, including during the prenatal window. As metals epidemiology moves towards embracing a multi-metal/mixtures approach and expanding metal panels to include less commonly studied metals, it is important for researchers to have a strong knowledge base about the metal biomarkers included in their research. This review aims to aid metals researchers in their analysis planning, facilitate sound analytical decision-making, as well as appropriate understanding and interpretation of results.

Using Fe biofortification strategies to reduce both Ni concentration and oral bioavailability for rice with high Ni

Due to naturally high Ni or soil Ni contamination, high Ni concentrations are reported in rice, raising a need to reduce rice Ni exposure risk. Here, reduction in rice Ni concentration and Ni oral bioavailability with rice Fe biofortification and dietary Fe supplementation was assessed using rice cultivation and mouse bioassays. Results showed that for rice grown in a high geogenic Ni soil, increases in rice Fe concentration from ∼10.0 to ∼30.0 μg g^-1 with foliar EDTA-FeNa application led to decreases in Ni concentration from ∼4.0 to ∼1.0 μg g^-1 due to inhibited Ni transport from shoot to grains via down-regulated Fe transporters. When fed to mice, Fe-biofortified rice was significantly (p < 0.01) lower in Ni oral bioavailability (59.9 ± 11.9% vs. 77.8 ± 15.1%; 42.4 ± 9.81% vs. 70.4 ± 6.81%). Dietary amendment of exogenous Fe supplements to two Ni-contaminated rice samples at 10-40 μg Fe g^-1 also significantly (p < 0.05) reduced Ni RBA from 91.7% to 61.0-69.5% and from 77.4% to 29.2-55.2% due to down-regulation of duodenal Fe transporter expression. Results suggest that the Fe-based strategies not only reduced rice Ni concentration but also lowered rice Ni oral bioavailability, playing dual roles in reducing rice-Ni exposure.

Risk Characterization of the Armenian Population to Nickel: Application of Deterministic and Probabilistic Approaches to a Total Diet Study in Yerevan City

Nickel (Ni) is a widespread metal that occurs in food and drinking water from both natural and anthropogenic sources. Oral exposure to Ni can induce a variety of adverse effects; the European Food Safety Authority established a tolerable daily intake (TDI) of 13 μg/kg bw and a lowest-observed-adverse-effect level (LOAEL) of 4.3 μg/kg bw to assess the risk of allergic reactions upon acute exposure. This study, the first conducted in Armenia, aimed to assess the dietary exposure of the adult Yerevan population (1272 subjects of both sexes) to Ni in a total diet study (TDS). Detection of Ni was carried out using atomic absorption spectrometry. To determine food consumption values, a 24-h recall survey was used. Following the K-means clustering test, two clusters were determined for food product intake. For the risk characterization of acute oral exposure, the margin of exposure (MOE) was calculated using both deterministic and probabilistic (Monte Carlo method) approaches. The average total exposure was 4.396 μg/kg bw, with limited influence by age and gender. The main contributors were "fruits and vegetables" followed by "bread and flour-based products": the total intake would be 5.11 μg/kg bw for a woman with high consumption of fruits and vegetables. Hence, the estimated chronic dietary exposure was below the TDI, irrespective of age and gender groups, and including high consumers. However, acute oral exposure estimates led to MOE values of less than 30 for most food products, indicating potential health concerns for Ni-sensitized individuals. The Monte Carlo approach indicated that the probability of occurrence of MOE lower than 30 was very high in the case of beef/veal, pork and chicken meat, eggs, and fish, alongside vegetable sources such as buckwheat, tomato, watermelon/melon, and potatoes. The findings prompt an investigation of Ni sources in the target foods in the Caucasus area.

New Insights and Evidence on "Food Intolerances": Non-Celiac Gluten Sensitivity and Nickel Allergic Contact Mucositis

The clinical examination of patients often includes the observation of the existence of a close relationship between the ingestion of certain foods and the appearance of various symptoms. Until now, the occurrence of these events has been loosely defined as food intolerance. Instead, these conditions should be more properly defined as adverse food reactions (AFRs), which can consist of the presentation of a wide variety of symptoms which are commonly identified as irritable bowel syndrome (IBS). In addition, systemic manifestations such as neurological, dermatological, joint, and respiratory disorders may also occur in affected patients. Although the etiology and pathogenesis of some of them are already known, others, such as non-celiac gluten sensitivity and adverse reactions to nickel-containing foods, are not yet fully defined. The study aimed to evaluate the relationship between the ingestion of some foods and the appearance of some symptoms and clinical improvements and detectable immunohistochemical alterations after a specific exclusion diet. One hundred and six consecutive patients suffering from meteorism, dyspepsia, and nausea following the ingestion of foods containing gluten or nickel were subjected to the GSRS questionnaire which was modified according to the "Salerno experts' criteria". All patients underwent detection of IgA antibodies to tissue transglutaminase, oral mucosal patch tests with gluten and nickel (OMPT), and EGDS, including biopsies. Our data show that GSRS and OMPT, the use of APERIO CS2 software, and the endothelial marker CD34 could be suggested as useful tools in the diagnostic procedure of these new pathologies. Larger, multi-center clinical trials could be helpful in defining these emerging clinical problems.

Irritable Bowel Syndrome-Like Disorders in Endometriosis: Prevalence of Nickel Sensitivity and Effects of a Low-Nickel Diet. An Open-Label Pilot Study

Alimentary nickel (Ni) may result in allergic contact mucositis (ACM), whose prevalence is >30% and may present with IBS-like and extra-intestinal symptoms. These symptoms are also frequent in endometriosis, and Ni allergic contact dermatitis has already been observed in endometriosis. Therefore, intestinal and extra-intestinal symptoms in endometriosis may depend on a Ni ACM, and a low-Ni diet could improve symptoms. We studied the prevalence of Ni ACM in endometriosis and focused on the effects of a low-Ni diet on gastrointestinal, extra-intestinal, and gynecological symptoms. We recruited 84 women with endometriosis, symptomatic for gastrointestinal disorders. Thirty-one out of 84 patients completed the study. They underwent Ni oral mucosa patch test (omPT), questionnaire for intestinal/extra-intestinal/gynecological symptoms, and a low-Ni diet. Clinical evaluation was performed at baseline (T0) and after three months (T1). Twenty-eight out 31 (90.3%) patients showed Ni omPT positive results, with Ni ACM diagnosis, whereas three out of 31 (9.7%) patients showed negative Ni omPT. After three months of low-Ni diet, all gastrointestinal, extra-intestinal and gynecological symptoms showed a statistically significant reduction. Ni ACM has a high prevalence in endometriosis and a low-Ni diet may be recommended in this condition to reduce gastrointestinal, extra-intestinal and gynecological symptoms.

Gap analysis of nickel bioaccessibility and bioavailability in different food matrices and its impact on the nickel exposure assessment

The metal nickel is well known to cause nickel allergy in sensitive humans by prolonged dermal contact to materials releasing (high) amounts of nickel. Oral nickel exposure via water and food intake is of potential concern. Nickel is essential to plants and animals and can be naturally found in food products or contamination may occur across the agro-food chain. This gap analysis is an evaluation of nickel as a potential food safety hazard causing a risk for human health. In the first step, the available data regarding the occurrence of nickel and its contamination in food and drinks have been collected through literature review. Subsequently, a discussion is held on the potential risks associated with this contamination. Elevated nickel concentrations were mostly found in plant-based foods, e.g. legumes and nuts in which nickel of natural origin is expected. However, it was observed that dedicated and systematic screening of foodstuffs for the presence of nickel is currently still lacking. In a next step, published studies on exposure of humans to nickel via foods and drinks were critically evaluated. Not including bioaccessibility and/or bioavailability of the metal may lead to an overestimation of the exposure of the body to nickel via food and drinks. This overestimation may be problematic when the measured nickel level in foods is high and bioaccessibility and/or bioavailability of nickel in these products is low. Therefore, this paper analyzes the outcomes of the existing dietary intake and bioaccessibility/bioavailability studies conducted for nickel. Besides, the available gaps in nickel bioaccessibility and/or bioavailability studies have been clarified in this paper. The reported bioaccessibility and bioavailability percentages for different food and drinks were found to vary between <LOD and 83% and between 0 and 30% respectively. This indicates that of the total nickel contained in the foodstuffs only a fraction can be absorbed by the intestinal epithelium cells. This paper provides a unique critical overview on nickel in the human diet starting from factors affecting its occurrence in food until its absorption by the body.

Chemometric determination of the shelf life of opened cans using the migration of specific metals as quality indicators

The aim of this work is the evaluation of quality indicators for the estimation of the shelf life of opened cans using the migration of specific metals as variables. For this reason the determination of targeted analytes such as: Cd, Pb, As, Cu, Cr, Ni, Fe, Mn and Sn in different canned samples (cardoon, tuna, green and red beans, corn, and fungi) by Electrothermal Atomic Absorption Spectrometry (Perkin Elmer, SIMAA 6000) was developed and validated. Statistical analysis was performed using SPSS version 22. Principal component analysis (PCA) and cluster analysis were performed in order to examine the correlation between the content of metals and metalloids and the storage time of opened cans. The results showed that there is a strong correlation between metal concentration and storage time, especially for Fe and Sn. The storage time ranged from hours to days and the vast number of collected data sets, led to reliable conclusions about the evaluation of a new shelf life indicator. Principal component analysis indicated the appropriate storage time for opened cans, where no significant migration was observed.

Essential and toxic elements in commercial baby food on the Spanish and Serbian market

About 10 heavy elements were determined in 90 samples of baby food collected from Spanish and Serbian market. The results indicated that iron, manganese and copper were most frequently detected. Tin was the predominant toxic element in both Spanish and Serbian samples, with occurrence frequencies of 12.5% and 10.0%, respectively. Element intake for Spanish and Serbian infants were estimated and compared with the recommended reference values, for the majority of elements being lower than one. However, iron and manganese intake through consumption of infant/follow-on formulas were assessed to be higher than the respective daily intakes. Particular attention should be paid to the exposure of infants who consume porridges made of vegetables and fish or chicken, because they may ingest certain elements, particularly arsenic and lead, at levels that exceed the reference toxicological values. Principal component analysis (PCA) was applied to classify and distinguish the different types of baby food.

Daily dietary intakes of zinc, copper, lead, and cadmium as determined by duplicate portion sampling combined with either instrumental analysis or the use of food composition tables, Shiraz, Iran

Estimation of essential and toxic element intakes is crucial to evaluate the risks of deficiency or toxicity. The purpose of this study was to investigate and also to compare the dietary intakes of zinc (Zn) and copper (Cu) by adults living in Shiraz, Iran, determined by two procedures: duplicate portion sampling of 21 hospital meals combined with either instrumental analysis (voltammetric measurement) or the use of food composition tables (FCTs). The level of exposure to lead (Pb) and cadmium (Cd) was evaluated as well. The daily Zn intakes of both methods were not significantly different and were higher than the RDA values except the value measured by the instrumental analysis which was lower than the RDA established for a male adult. Daily intake of Cu determined by instrumental analysis was significantly lower and closer to RDA for adults compared with the value estimated by FCTs. The dietary intakes of Pb and Cd were 313 and 61% of the respective provisional tolerable weekly intakes (PTWIs), respectively. The accuracy of two methods used for estimation of Zn intake was similar. In the case of Cu, the use of FCTs, in which the influence of environmental conditions and dietary habits of meal preparation is not taken into account, overestimated dietary intake. The risk of zinc deficiency was found in adult males. Moreover, the estimated intake of Pb, but not Cd, could be a cause of concern for Shiraz population. Thus, conducting regular periodic studies to assess the dietary intake of mentioned elements are recommended.

Metals in commonly eaten groceries in Western Australia: a market basket survey and dietary assessment

Children's dietary exposure to metals has received limited attention in Australia. This study undertook a market basket survey and analysed 253 food and beverages for metals. These data were used in conjunction with recent average diet data for children in Western Australia to model dietary metals exposure, with mean metals intakes calculated for boys and girls aged 8, 12, 13 and 16 years. Results show that for some metals, including cadmium, nickel and manganese, dietary intake guidelines have been exceeded in younger children. The mean modelled cadmium intake in children aged 8 years was almost 60% of the World Health Organisation (WHO) guideline and exceeded the European Food Safety Authority (EFSA) guideline. Nickel and manganese intake was higher in younger children than reported in international studies. Modelling based on the 95% percentile of dietary consumption exceeded the respective guidelines or upper level of intake for several of the metals studied. The findings from this study support the need for further investigation into the exposure of children to metals from diet and the health implications of exposure.

Zinc deficiency and toxicity in pediatric practice

PURPOSE OF REVIEW

Zinc is a commonly overlooked deficiency in developed countries, occurring in infants, children, and adolescents during critical growth periods. The purpose of this review is to present the evidence of zinc deficiencies and toxicities as well as treatment in pediatrics.

RECENT FINDINGS

During the last decade, the significance of zinc deficiency in childhood growth, morbidity, and mortality has been recognized by a number of large-scale supplementation trials in underdeveloped countries. Recognition of the recent nationwide shortage of injectable zinc available for total parenteral nutrition supplementation over the last 2 years focused attention on the possibility of zinc deficiency in the United States.

SUMMARY

Although primarily thought of as a problem reserved for underdeveloped countries, zinc deficiency has increasing pediatric prevalence in the USA. Zinc is an essential trace element in the body that is responsible for numerous structural, catalytic, and biochemical functions. Deficiencies can occur because of poor dietary intake, long-term parenteral nutrition without supplementation, and enteral causes such as malabsorption. Zinc deficiency is closely associated with stunting, respiratory infections, diarrhea, and dermatitis. Deficiency is hard to define solely by the serum levels. Clinicians should utilize a combination of serum zinc levels, presenting signs and symptoms, and nutritional intake via oral, enteral, and parenteral routes to accurately assess the deficiency risk and diagnosis.

Dietary exposure and risk assessment to lead of the population of Jiangsu province, China

The paper's main purpose is to estimate the dietary exposure to lead for the inhabitants of Jiangsu province, China. Lead concentration data were obtained from the national food contamination monitoring programme during 2007-10. Food samples (n = 2077) were collected from 23 food categories in Jiangsu province. Consumption data were derived from Chinese national nutrition and health survey in 2002, which included 3938 inhabitants from 1451 households in Jiangsu province. Concentration data were combined with consumption data to estimate the dietary intake for the inhabitants of 2-6, 7-17 and 18-80 years, respectively. The β-binomial-normal (BBN) model was used to estimate the long-term intake for the population in Jiangsu province. The distribution of individual margin of exposure (IMoE) was introduced to assess the health effect. Uncertainty of IMoE was quantified by Monte Carlo and bootstrap methods. The mean levels of dietary exposure to lead were estimated at 3.019 µg kg(-1) bw day(-1) for children aged 2-6 years, 2.104 µg kg(-1) bw day(-1) for teenagers aged 7-17 years, and 1.601 µg kg(-1) bw day(-1) for adults aged 18-80 years. The mean intakes for the urban and rural populations were 1.494 and 1.822 µg kg(-1) bw day(-1), respectively. From the 25th to 99.9th percentiles, IMoE was 0.125-2.057 for 2-6 years and 0.473-7.998 for 18-80 years, respectively. The distribution of IMoE could indicate a public health concern on lead for the Chinese population in Jiangsu. Control measures should be taken to reduce lead exposure in Jiangsu province.

Study of the migration phenomena of specific metals in canned tomato paste before and after opening. Validation of a new quality indicator for opened cans

A method for the simultaneous determination of Cd-Pb, As-Cu, Cr-Ni and Fe-Mn in canned tomato paste samples by Electrothermal Atomic Absorption Spectrometry was developed and validated. The validation procedure was conducted according to the terms of the European regulation for the official control of contaminants in foods. The validated method was applied for the determination of these metals and metalloids in 13 different tomato paste samples and the results showed that Cd content was higher than the maximum permissible value of 0.050 mg kg(-1) as proposed in European Regulation (EC) No 1881/2006 concerning fresh fruits and vegetables. Furthermore, a new quality indicator was evaluated in order to provide information about tomato paste quality and the appropriate storage time of an opened canned tomato paste. Finally, a migration test was accomplished based on the calculation of mass balance and the comparison of the elemental content in canned tomato paste samples and in aseptic paper pack and it was proved that Fe and Pb were the main metals migrating in tomato paste samples.

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.

Systemic contact dermatitis

Systemic contact dermatitis is an inflammatory skin disease that may occur in persons with contact allergy when they are exposed to the hapten orally, transcutaneously, per rectum, intravesically, intravenously, or by inhalation. The most common causes of systemic contact dermatitis are drugs used both topically and systemically. Other causes are ubiquitously occurring haptens, such as the metals nickel, cobalt, gold, and chromate, and aromatic substances such as spices. Avoidance of the offending hapten is the most obvious treatment. For some haptens, such as nickel, diet treatment may be effective. Chelation therapy with disulfiram is another therapeutic option in nickel-allergic patients with systemic contact dermatitis. Hyposensitization therapy has been attempted with some success in systemic contact dermatitis caused by nickel and Parthenium hysterophorus.

Assessment of indirect human exposure to environmental sources of nickel: oral exposure and risk characterization for systemic effects

This paper describes the indirect human exposure to Ni via the oral route for the regional scale in the EU, together with a method to assess additional local exposure from industrial emissions. The approach fills a gap in the generic REACH guidance which is inadequate for assessing indirect environmental exposure of metals. Estimates of regional scale Ni dietary intake were derived from Ni dietary studies performed in the EU. Typical and Reasonable Worst Case dietary Ni intakes for the general population in the EU were below the oral Derived No Effect Level (DNEL) of Ni sulfate for systemic effects. Estimates for the Ni dietary intake at the local scale take into account the influence of aerial Ni deposition and transfer from soil to crops grown near industrial plants emitting Ni. The additional dietary exposure via this local contribution was small. Despite the use of conservative parameters for these processes, this method may underestimate dietary exposure around older industrial sites because REACH guidance does not account for historical soil contamination. Nevertheless, the method developed here can also be used as a screening tool for community-based risk assessment, as it accounts for historical soil pollution. Nickel exposure via drinking water was derived from databases on Ni tap water quality. A small proportion of the EU population (<5%) is likely to be exposed to tap water exceeding the EU standard (20 μg Ni/l). Taking into account the relative gastrointestinal absorption of Ni from water (30%) versus from solid matrices (5%), water intake constitutes, after dietary intake, the second most important pathway for oral Ni intake. Incidental ingestion of Ni from soil/dust at the regional scale, and also at the local scale, was low in comparison with dietary intake.

Acquired acrodermatitis enteropathica due to zinc deficiency in a patient with pre-existing Darier's disease

BACKGROUND

Acrodermatitis enteropathica is characterised by inflamed patches of dry red skin which then become crusted and blistered before revealing a pustulent eroded lesion. Typically these patches start near the body's orifices before migrating to other sites, however in this patient the presentation was atypical thus delaying the diagnosis.

OBSERVATIONS

We report a case of an atypical presentation of acrodermatitis enteropathica (AE) due to acquired zinc deficiency in a 65 year old female patient with a previous diagnosis of histologically confirmed Darier's disease. This patient's rash began on the limbs and trunk before progressing to include the perineum, oral mucosa and nose. Diffuse loss of hair on scalp, eyebrows and eyelashes was observed. Acrodermatitis enteropathica typically presents in infants, either due to an autosomal recessive genetic disorder, or after the cessation of breast feeding. In adults acquired zinc deficiency can be caused by glucagonoma syndrome, poor nutritional state, intestinal malabsorption, nephrotic syndrome and after major trauma (i.e. burns or significant surgery). In our patient low zinc levels confirmed hypozincaemia and the diagnosis of acrodermatitis enteropathica. The patient started oral zinc replacement. Within a few days her symptoms began to improve, and her hair has started to grow.

CONCLUSION

We believe this to be an unusual presentation of acrodermatitis enteropathica due to a probable dietary zinc deficiency in a lady with pre-existing Darier's disease which may possibly have influenced the uncharacteristic clinical presentation.

Nickel levels in convenience and fast foods: in vitro study of the dialyzable fraction

Nickel presence was determined in 170 samples of 43 different convenience and fast foods widely consumed in Spain. Electrothermal atomic absorption spectrometry was used as analytical technique. Reliability of the procedure was checked. Ni levels ranged from 18.50 to 95.00 ng g(-1) (fresh weight of edible portion). The most elevated Ni concentrations were found in egg- and pork-based foods and in sauces but there is a high variability inside of each one of these foods. Ni content increases in products that contain spices and aromatic herbs, whole cereals, dry fruits, cheese and mushrooms. Mean Ni dialyzable fraction estimated by in vitro assays ranged from 4.50 to 7.75%. This study shows that the probability of exposure to health risks from these foods is overall small. However, the present findings are of potential use in food composition tables and to estimate the Ni dietary intake and tolerable intake levels in accordance with the current dietary habits.

Prevalence of nickel sensitization and urinary nickel content of children are increased by nickel in ambient air

In a cross-sectional study performed in 2000, an unexpected positive association between nickel (Ni) in ambient air, urinary Ni content and the prevalence of Ni sensitization in a subgroup of 6-yr-old children living near a steel mill was observed. Between 2005 and 2006, in a different and larger study population, we examined if Ni from ambient air or urinary Ni concentration was related to Ni sensitization in children living next to Ni-emitting steel mills. We studied 749 school beginners living in four Ni-polluted industrial areas of North Rhine-Westphalia, Germany. We assessed Ni in ambient air, Ni in urine from children and mothers, and Ni in tap water, conducted patch tests in children (including the NiSO(4)-dilution test) and collected questionnaire data. Statistics were done by linear and logistic regression analyses, adjusted for covariates. At increased Ni concentration in ambient air (unit of increase: 10 ng/m(3)), urinary Ni concentrations rose in both mothers (9.1%; 95% CI: 6.8-11.4%) and children (2.4%; 95% CI: 0.4-4.4%). The prevalence of Ni sensitization in children was associated with increased Ni from ambient air (unit of increase: 18 ng/m(3); odds ratio 1.28; 95% CI: 1.25-1.32) and urinary Ni concentration (unit of increase: 7.1 μg/L; odds ratio 2.4; 95% CI: 1.20-4.48). Ni in ambient air of areas with Ni-emitting factories contributes to internal Ni exposure in residents via inhalation and, furthermore, is a risk factor for the development of Ni sensitization in children.

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.