Dietary Intake Of Lead Research Articles

Impact of Diet on Lead in Blood and Urine in Female Adults and Relevance to Mobilization of Lead from Bone Stores

We measured high precision lead isotope ratios and lead concentrations in blood, urine, and environmental samples to assess the significance of diet as a contributing factor to blood and urine lead levels in a cohort of 23 migrant women and 5 Australian-born women. We evaluated possible correlations between levels of dietary lead intake and changes observed in blood and urine lead levels and isotopic composition during pregnancy and postpartum. Mean blood lead concentrations for both groups were approximately 3 microg/dl. The concentration of lead in the diet was 5.8 +/- 3 microg Pb/kg [geometric mean (GM) 5.2] and mean daily dietary intake was 8.5 microg/kg/day (GM 7.4), with a range of 2-39 microg/kg/day. Analysis of 6-day duplicate dietary samples for individual subjects commonly showed major spikes in lead concentration and isotopic composition that were not reflected by associated changes in either blood lead concentration or isotopic composition. Changes in blood lead levels and isotopic composition observed during and after pregnancy could not be solely explained by dietary lead. These data are consistent with earlier conclusions that, in cases where levels of environmental lead exposure and dietary lead intake are low, skeletal contribution is the dominant contributor to blood lead, especially during pregnancy and postpartum.

Contribution of lead in wine to the total dietary intake of lead in humans with and without a meal: a pilot study

Several studies have suggested that intake of alcoholic beverages contributes significantly to the concentration of lead in blood. We have undertaken a pilot case‐control study using high‐precision lead isotopes to evaluate the contribution to blood lead when a normal quantity of wine is consumed with a meal and compared this with consumption under fasting conditions. White wine dosed with a 207Pb tracer was consumed with a meal and under fasting conditions, and blood, urine and faeces were monitored for up to 4 months. Approximately equal proportions of unspiked red and white wine were consumed over the 4 months by the subject and a female subject residing in the same household. The blood lead concentration of the case subject was 4.1 μg dl‐1 and 3.4 μg dl‐1 in the control subject. No increase in the concentration of lead in blood for the wine consumed with a meal was detectable, but there was an approximately 6% increase in blood lead concentration for wine consumed under fasting conditions. When consumed with a meal, the percentage absorption at 24 h was only 2.3%, compared with approximately 34% under fasting conditions. For the consumption of wine with a meal, the half‐life for uptake of lead from the wine was 8.6± 1.7 h with a rate constant of 0.081 ± 0.016/h and the clearance of lead from blood had a half‐life of 23 days with a rate constant of 0.21/week. For consumption of wine under fasting conditions, the half‐life was 5.4 ± 1.5 h with a rate constant of 0.13 ± 0.04/h. An additional control was possible because of marked difference in the ratios of the white wine compared with the prevailing Australian isotopic signature. Over the 4 months of the trial, there was no detectable change in the other isotopic ratios in both subject and control, confirming the minimal uptake of lead from wine when consumed with food.

Maize and foxtail millet as substantial sources of dietary lead intake

In 1996, 24-h food duplicate samples were collected from two groups of 50 non-smoking women each; one group was in Jinan, the capital city of Shandong Province in China, and the other in a farming village in the Zhangqiu area some 30 km away from the city. The people in the village took significantly more dietary lead (46 μg/day) than their counterparts in the city (26 μg/day), and blood lead concentrations (35 and 50 μg/l for the urban and the rural people, respectively) were in parallel with the dietary lead intake. Search for cereals as the determinants of dietary lead intake and blood lead concentration by multiple regression analysis showed that maize was the most influential source of dietary lead intake among the four common cereals of wheat, rice, foxtail millet (to be called just millet) and maize, whereas millet was the leading determinant of the blood lead level among the four cereals although the influential power was weaker than millet for dietary lead. Lead content in maize (47 ng/g) and millet (47 ng/g) was twice or even more times higher than the levels in wheat (26–30 ng/g) and rice (20–21 ng/g). The significant roles of non-rice/non-wheat cereals such as millet and maize as possible dietary lead sources for farming populations are discussed.

Dietary Lead Intakes for Mother/Child Pairs and Relevance to Pharmacokinetic Models

Dietary Lead Intakes for Mother/Child Pairs and Relevance to Pharmacokinetic Models

Impact of reduction of lead in gasoline on the blood and hair lead levels in the population of Tarragona Province, Spain, 1990–1995

The limitation in the use of lead in Spanish gasoline has induced a resulting decrease in atmospheric lead concentrations, a remarkable reduction in the lead levels of edible vegetables, as well as a marked decrease in the dietary lead intake of the population of Tarragona Province (Catalonia, N.E. Spain). The present study evaluates the impact of such decreases on blood lead values and hair lead concentrations in an adult and children population of that region. A total of 250 adult participants between 16–65 years of age and 252 children were included in the study. Blood and hair samples were subjected to lead analyses by graphite furnace atomic absorption spectrophotometry and inductively coupled plasma spectrometry, respectively. A substantial decline in both, blood lead levels in adults (47.5%) and lead concentrations in children's hair (53%) was observed. During the period 1990–1995, blood lead levels were reduced from 12.0 μg dl−1 to 6.3 μg dl−1, while the hair lead concentrations decreased from 8.8 μg g−1 to 4.1 μg g−1. These decreases were noted for all the subgroups (sex, age and place of residence) examined, and were mainly attributable to the reduced leaded gasoline consumption.

Estimation of dietary intake of lead and cadmium in the general population of the Republic of Croatia

The level of lead and cadmium in foodstuffs in the Republic of Croatia was determined by the method of atomic absorption spectrophotometry from the beginning of 1988 to mid 1993. Mean weekly dietary intake of these toxic metals was then estimated on the basis of the level of contamination and consumption of the foodstuffs concerned. The results show that mean weekly dietary intake of lead is 701 μg/person and 121.4 μg cadmium/person. With respect to the provisional tolerable weekly intake (PTWI), these values are equal to 19.9% for lead and 24.4% for cadmium.

Non-occupational exposure of Malay women in Kuala Lumpur, Malaysia, to cadmium and lead

Abstract Peripheral blood and 24-h total food duplicate samples were obtained from 49 adult Malay women in Kuala Lumpur, Malaysia, in July, 1995. Samples of boiled and uncooked (raw) rice were also collected from the subjects. The blood samples, homogenates of each food duplicates and rice samples (both cooked and raw) were digested by heating in the presence of mineral acids, and the digests were subjected to analysis for cadmium (Cd) and lead (Pb) with a system composed of a fully automated liquid sampler, a graphiie furnace atomic absorption spectrometer and a data processor. The geometric mean metal concentrations in blood were 0.71 ng Cd per ml and 45.6 ng Pb per ml, and the dietary metal intakes were 7.31 μg Cd per day and 10.1 μg Pb per day. The metal intake via rice accounted for 53% and 13% of total dietary intake of cadmium and lead, respectively. When the absorption from the air and foods was compared, the cadmium burden came almost exclusively from foods, whereas the lead burden came both from air (44%) and foods (56%).

Food surveillance in the Basque Country (Spain). II. Estimation of the dietary intake of organochlorine pesticides, heavy metals, arsenic, aflatoxin M1, iron and zinc through the Total Diet Study, 1990/91

Total diet samples purchased at monthly intervals between March 1990 and December 1991 were analysed for different contaminants and nutrients. Each total diet sample included 91 food items which were combined after preparation and/or cooking into 16 groups of similar foods. The 'market basket' was based on a food survey which referred to the adult population (25-60 years) carried out in the Basque Country between 1988 and 1990. The dietary intakes (micrograms/day) of lead (43), cadmium (11), mercury (18), arsenic (291), hexachlorobenzene (HCB) (0.2), alpha-hexachlorocyclohexane (alpha-HCH) ( < 0.1), beta-hexachlorocyclohexane (beta-HCH) (0.1), gamma-hexachlorocyclohexane (gamma-HCH) (2.9), dichlorodiphenyltrichloroethane (DDT) (0.3), dichlorodiphenyldichloroethene (DDE) (0.9), dichlorodiphenyldichloroethane (DDD)(0.2), dieldrin (0.5), heptachlor epoxide ( < 0.1), alpha-endosulphan (0.1) and beta-endosulphan (0.1) were all well below the respective Acceptable Daily Intakes or Provisional Tolerable Weekly Intakes. However, arsenic intake was much higher than that estimated in other countries and gamma-HCH was detected in anomalously high levels in the bread group. Dietary intakes of delta-hexachlorocyclohexane (delta-HCH), aldrin, endrin, heptachlor and methoxychlor were not calculated because no residues were detected in any of the samples. Aflatoxin M1 intake was not estimated owing to the low levels detected. Finally, zinc intakes (11.6 mg/day) were below the recommended dietary allowances for Spain and the same was true for iron (11.3 mg/day), but only for females.

Occupational and environmental health in Mauritius: a review of trends and recent studies

Environmental health—in the general environment and workplaces—is often ignored or undervalued in rapidly developing countries. This paper reports the evolution of a system of legislation and inspection for occupational and environmental health in Mauritius in recent years. It then discusses the findings of empirical studies of air pollution, exposure to vehicular lead and dietary lead intake. It finally discusses the health and safety findings in 16 factories. These studies, findings and legislation have encouraged the training of personnel in environmental health and it is hoped that this will gradually enhance occupational and general population health in the rapidly developing island.

Lead and cadmium contents in milk, cheese and eggs on the Finnish market.

Lead and cadmium contents were determined in nationally representative samples of low-fat milk, cheese and eggs consumed in Finland. Nationally representative samples of milk and cheese were collected from dairies. Egg samples were collected from the major distributors. Samples of imported cheese and egg products collected in surveillance studies were analysed, together with domestic samples. Lead and cadmium were determined by GFAAS after wet digestion in conc. HNO3. In lead determinations of milk and cheese platinum was employed as the matrix modifier and NH4H2PO4 was employed for the lead determinations of eggs and in all cadmium determinations. Mean lead content was 1.7 micrograms/kg in milk, 17 micrograms/kg in Finnish cheese, 17-60 micrograms/kg in imported cheese, 1 microgram/kg in eggs and 6-72 micrograms/kg in imported dry egg products. Although Finnish consumption in milk, cheese and eggs is high the dietary intake of lead and cadmium from these sources is very low compared with the tolerance limits.

Dietary Intake of Cadmium and Lead among the General Population in Korea

This survey was conducted in Seoul, Pusan, Chunan, and Haman in Korea to clarify cadmium and lead burden in the general Korean populations in terms of dietary intake of cadmium and lead and the concentrations of the two metals in blood. People who participated in the study were 141 healthy nonsmoking women aged 21-56 years. Determination of cadmium and lead in 24-hr food duplicates and blood samples was carried out by graphite furnace atomic absorption spectrophotometry. The geometric means for the four sites in combination were 21.2 μg/day for dietary cadmium, 20.5 μg/day for dietary lead, 1.27 ng/ml for blood cadmium, and 44.3 ng/ml for blood lead. Cadmium intake from boiled rice accounted for 23% of total daily cadmium intake. The counterpart value for lead intake from boiled rice was 12%. Blood cadmium levels and dietary cadmium intake were lower and blood lead level and dietary lead intake were higher in Korean women than in Japanese women. The values for dietary cadmium are similar to, and the values for dietary lead are somewhat lower than, the levels reported from Europe and the United States. Dietary intake was the main source of cadmium exposure, whereas lead exposure was from both ambient air and foods in the Korean population.

Role of rice and cereal products in dietary cadmium and lead intake among different socio-economic groups in south India.

A study was conducted to evaluate the concentration of cadmium and lead in rice and cereal products commonly consumed in South India. Samples from retail outlets were purchased and analysed for cadmium and lead using graphite tube atomic absorption spectrophotometry. The results indicated varying concentrations of these metals in different rice and cereal products. The daily dietary intake of cadmium and lead varied among different socio-economic groups, based on occupation, and choice of consumption. The findings suggest that rice is the major source of cadmium and lead among the rural population and economically-deprived class. The source of intake of toxic metals appears to be more diverse in the case of the urban middle class and the economically privileged class of South India.

Effects of maternal lead exposure on functional plasticity in the visual cortex and hippocampus of immature rats

We examined the amount of long-term potentiation (LTP) in slices from the visual cortex and hippocampus of pre- and postnatally lead-exposed rats and controls at postnatal days (PND) 12–20. A dietary lead intake of 750 ppm by the dams resulted in a mean blood lead concentration in the suckling offspring of about 17 μg/dl. While high-frequency stimulation (HFS) of the white matter induced LTP of the field potentials in layers II/III in cortical slices of ten out of the 14 control rats, only three of the twelve lead-exposed rats showed a small amount of LTP. However, in slices from seven of the twelve lead-exposed rats a long-term depression was found following HFS. Furthermore, paired-pulse inhibition was weaker in cortical slices from the lead-exposed as compared to the control rats. In the CA1 hippocampal region the amount of LTP was significantly reduced in the lead-exposed group only in slices taken from rats at PND 16–20, while no differences were seen in slices from younger animals. It is concluded that even low level lead exposure impairs functions of the visual cortex in the immature rat. We suggest that the developing hippocampus is able to compensate for lead-induced functional deficits in the 2nd postnatal week, being more vulnerable at older ages.

Atmospheric deposition of trace elements around point sources and human health risk assessment. I: Impact zones near a source of lead emissions

The deposition of lead was monitored over 8 years in the area around a car battery factory north of Copenhagen, Denmark. The area also has heavy traffic. Deposition was measured by in-situ grown vegetables, transplant grass culture biomonitors, bulk deposition and soil samples. Three impact zones were identified by a multivariate statistical analysis. Within each zone, the total dietary intake of lead was estimated for adults and children as a percentage of the provisional tolerably weekly intake (PTWI), and as a result recommendation on restrictions in use of locally grown fruit and vegetables were given to the public. The pattern of lead deposition in the area during the period 1981–1988 was monitored and the amount of lead ingested via vegetables was toxically evaluated. Lead emission reduction measures introduced in the factory and in the traffic during the period produced significant reductions in lead deposition.

Role of the Food Chemicals Codex in Lowering Dietary Lead Consumption: A Review

Because chemicals used in the production of food constitute a significant portion of the U.S. diet, reducing lead levels in them is one of the long-term objectives of the Committee on Food Chemicals Codex, a committee of the Food and Nutrition Board within the Institute of Medicine. The Committee recommends limits for lead, as well as for other heavy metals, arsenic, and other potentially hazardous constituents in chemicals used in food production. Food Chemicals Codex specifications often become legal standards for food chemical purity in the United States and other countries throughout the world. The Committee plans to lower lead limits for food chemicals based on their level of consumption or reported use. Data regarding food chemical use are available from the 1987 Poundage and Technical Effects Update of Substances Added to Food. Because of their high level of consumption, sweeteners constitute a group of food chemicals in which lower lead limits could reduce dietary lead intake. A test method capable of measuring lead at lower levels in certain sweeteners has been published in the third supplement to the Food Chemicals Codex, 3rd edition. The Committee's objective is to ensure that the substances listed in the Food Chemicals Codex do not contribute significant amounts of lead to the diet.

Determination of Human Exposure to Lead and Cadmium: A WHO/UNEP Pilot Study

In Stockholm, methods for measuring exposure to lead and cadmium from air, food and beverages were studied in 1988 in a group of 15 non-smoking women, as part of the WHO/UNEP HEAL programme. Airborne particles in the breathing zone air (24-hour samples), duplicate diets (24-hour samples), and faeces (all the stools produced) were collected during 7 consecutive days. Blood was sampled before and immediately after the study period. The results confirmed the need for personal monitoring in the assessment of human exposure to lead and cadmium via air and food. There is need for suitable equipment for 24-hour personal air monitoring. On average, dietary lead (26 μg day−1, SD 7.9) contributed more than 80% of the total lead uptake, while dietary cadmium (8.5 μg day−1 SD 2.1) contributed about 99% of the total cadmium uptake. Occasionally consumed foodstuffs with high levels of lead or cadmium seemed to be responsible for a large part of the total weekly intake of lead and cadmium. Fecal lead and cadmium were found to be useful indicators of the total amounts of these metals ingested. Due to the large day-to-day variation observed in the dietary intake of lead and cadmium, the sampling period for duplicate diets and faeces should be at least 5–6 days.

The Drive to Lower Lead Levels in Food Chemicals

Because chemicals that are intentionally added to food during its production constitute a significant portion of the US diet, reducing lead levels in them is one of the long-term objectives of the Committee on Food Chemicals Codex, a committee of the Food and Nutrition Board within the Institute of Medicine. The Committee recommends limits for lead, as well as for other heavy metals, arsenic, and other potentially hazardous constituents in chemicals used in food production. The Food Chemicals Codex is a compendium of purity specifications that often become legal standards for food chemical purity in the United States and in many countries worldwide. The Committee plans to lower existing lead limits for food chemicals based on their level of consumption or reported use. Data regarding food chemical use is available from the 1987 Poundage and Technical Effects Update of Substances Added to Food. Because of their high level of consumption, sweeteners constitute a group of food chemicals in which lead limits could be lowered. However, the Committee's ability to recommend lower lead limits in these products depends on the availability of a test method capable of measuring lead at lower levels. This Committee intends to make its contribution in the effort to lower dietary intake of lead.

Methods for Assessment of Dietary Lead Exposure of the Inner-City Population

AbstractAssessment of dietary lead exposure of individuals begins with the determination of food and beverage intake by the individuals, and concludes with an evaluation of the lead content of the foods and beverages consumed. Of several techniques available for assessment of dietary intake, the 24-hour food recall is recommended as the method of choice for assessing current dietary lead intakes in inner-city populations. The three-day food record can be used among cooperative and motivated subjects, while the dietary history method is available for assessing long-term intakes in the past. The unavailability of lead content values of a large number of foods will to a large extent restrict the use of these methods in large-scale dietary lead exposure studies. Until the time that such data becomes available, the most accurate estimates of lead intake can be provided by chemical analysis of duplicate samples of foods consumed, as is currently done. However, this method is feasible only for small samples.

Dietary Exposure to Lead and Cadmium in Sweden

A duplicate diet study on male and female pensioners in 1970–71 showed mean daily dietary lead intakes of 30 μg and 19 μg respectively. The corresponding cadmium intakes were 10.5μg and 12.9 μg. Analysis of duplicate diets collected during seven consecutive 24-hour periods from 15 women in Stockholm in 1988 showed a mean daily lead intake of 26 μg (range 13–40 μg). The corresponding cadmium intake was 8.5μg (range 5.7–14 μg). Analysis of faeces samples corresponding to the duplicate diets showed similar lead and cadmium contents (mean lead content 24 μg day−1, range 10–41 μg day−1; mean cadmium content 8.9 μg day−1 range 5.5–12 μg day−1). The median lead and cadmium concentrations in human milk collected in Uppsala were 2 μg kg−1 and 0.1 mg kg−1 respectively. The median weekly intakes of lead and cadmium by the breast-fed infants were calculated to be 2 μg kg−1 body weight and 0.1 μg kg−1 body weight. Analysis of seven daily diets, together representing the weekly diet of an adult Swedish male, showed a mean lead content of 26 μg (range 15–45 μg), and a mean cadmium content of 10 μg (range 7–15 μg). The mean daily intakes of lead and cadmium found by analysing market baskets prepared in 1987 were 17μg and 12μg respectively. Calculations based on food balance sheet data and levels of lead and cadmium in individual foods showed mean daily intakes of 30 μg lead and 14 μg cadmium per person.

Dietary intake of pesticide residues: Cadmium, mercury, and lead

Information on the dietary intake of chemical contaminants has been obtained from institutions participating in GEMS/Food. Contaminants studied include certain organochlorine and organophosphorous pesticides, PCBs, cadmium, mercury, and lead. The intakes are compared with toxicologically acceptable intake levels established by international expert groups. In most cases, dietary intakes of organochlorine and organophosphorous pesticides are well below the Acceptable Daily Intake (ADI) of the respective pesticide. Of some 21 countries providing information on the average dietary intake of cadmium, only in one case is the Provisional Tolerable Weekly Intake (PTWI) exceeded. Several countries identified cereals and cereal products and root and tuber vegetables as the main contributors to the dietary intake of cadmium. For mercury, all reported intakes are below the PTWI of methylmercury. The contribution of fish to the total intake of mercury varied from 20% to 85%, depending on the country. Therefore, the general assumption that fish is the main contributor to the total dietary intake of mercury may, at times, not be justified. Average dietary intake of lead exceeding or approaching the PTWI are reported for adults and infants and children in some countries. Foodstuffs which contribute most to the intake of lead vary from country to country, and have been identified as being alternately drinking water, beverages, cereals, vegetables and fruit.