Aluminum levels in human milk

Toxicity and biokinetics following pulmonary exposure to aluminium (aluminum): A review

During the manufacture and use of aluminium (aluminum), inhalation exposure may occur. We reviewed the pulmonary toxicity of this metal including its toxicokinetics. The normal serum/plasma level based on 17 studies was 5.7 ± 7.7µg Al/L (mean ± SD). The normal urine level based on 15 studies was 7.7 ± 5.3µg/L. Bodily fluid and tissue levels during occupational exposure are also provided, and the urine level was increased in aluminium welders (43 ± 33µg/L) based on 7 studies. Some studies demonstrated that aluminium from occupational exposure can remain in the body for years. Excretion pathways include urine and faeces. Toxicity studies were mostly on aluminium flakes, aluminium oxide and aluminium chlorohydrate as well as on mixed exposure, e.g. in aluminium smelters. Endpoints affected by pulmonary aluminium exposure include body weight, lung function, lung fibrosis, pulmonary inflammation and neurotoxicity. In men exposed to aluminium oxide particles (3.2µm) for two hours, lowest observed adverse effect concentration (LOAEC) was 4mg Al2O3/m3 (= 2.1mg Al/m3), based on increased neutrophils in sputum. With the note that a similar but not statistically significant increase was seen during control exposure. In animal studies LOAECs start at 0.3mg Al/m3. In intratracheal instillation studies, all done with aluminium oxide and mainly nanomaterials, lowest observed adverse effect levels (LOAELs) started at 1.3mg Al/kg body weight (bw) (except one study with a LOAEL of ~0.1mg Al/kg bw). The collected data provide information regarding hazard identification and characterisation of pulmonary exposure to aluminium.

Heavy Metals and Trace Elements in Human Breast Milk from Industrial/Mining and Agricultural Zones of Southeastern Spain

Human breast milk is the most complete foodstuff for infants but can also be a potential source of exposure to toxic chemicals. The aim of this study was to assess the levels of metal pollution in the breast milk of women living in agricultural and industrial/mining areas of the Region of Murcia (Spain) that are well known for their cases of environmental pollution. Human milk samples were collected from 50 mothers and inorganic contaminants were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The mean or maximum concentrations of the different inorganic elements analyzed in breast milk, with the exception of manganese, exceeded the maximum limits established by the WHO and could constitute a high risk for pregnant mothers and their children. The breast milk of women living in the industrial/mining zone presented the highest levels of aluminum, zinc, arsenic, lead, mercury and nickel. On the contrary, the highest concentrations of manganese, chromium and iron were determined in the milk of women living in the agricultural zone. These results suggested and confirmed different profiles of environmental contamination of these areas.

Aluminum Content of Human Milk and Antiperspirant Use

Background: Aluminum exposure may originate from numerous sources, including antiperspirants. Aluminum toxicity can cause a wide range of neurological impairments. Infants are exposed to aluminum through human milk (HM), formulas, total-parenteral-nutrition and vaccines. Due to potential risk of toxicity to both infants and women, it has been advised that lactating women decrease their use of aluminum-based products and antiperspirants. Our study aimed to determine whether the use of aluminum-based antiperspirants (ABA) affects aluminum levels in HM. Methods: This cross-sectional study included healthy mothers who exclusively breastfed infants (1 week to 5 months). Questionnaires were used to collect data on demographics, antiperspirant use and aluminum exposure. Mothers were instructed to express HM during the morning at first breastfeeding session. Aluminum levels were measured by atomic absorption spectrometry with a 5 ppb limit of detection. Results: Fifteen of the 58 (26%) recruited mothers used an aluminum-free antiperspirant (AFA) and 43 (74%) used an ABA. The range of aluminum concentration in HM was 0-100.8 μg/L (mean 11.4 ± 17.4 μg/L). The median aluminum level (Q1-Q3) was 6.5 μg/L (5.2-11.9) and 5.2 μg/L (3.46-9.4) in the AFA and ABA groups, respectively (p = 0.19). The aluminum levels were not affected by maternal age, education, diet, number of children, infant age, lactation stage or self-reported aluminum exposure. Conclusion: The data from this preliminary study demonstrate that the use of an ABA by lactating mothers does not increase their HM aluminum content. Additional studies with a larger cohort are warranted to confirm these findings.

Neurotoxic effects of combined exposures to aluminum and mercury in early life (infancy)

Aluminum and mercury are environmentally ubiquitous. Individually they are both neurotoxic elements with shared neuro-pathogenic pathways: oxidative stress, altered neurotransmission, and disruption of the neuroendocrine and immune systems. In the infant, Al and Hg differ in type of exposure, absorption, distribution (brain access), and metabolism. In environmentally associated exposure (breast milk and infant formulas) their co-occurrences fluctuate randomly, but in Thimerosal-containing vaccines (TCVs) they occur combined in a proprietary ratio; in these cases, low-doses of Thimerosal-ethylmercury (EtHg) and adjuvant-Al present the most widespread binary mixture in less developed countries. Although experimental studies at low doses of the binary Hg and Al mixture are rare, when studied individually they have been shown to affect neurological outcomes negatively. In invitro systems, comparative neurotoxicity between Al and Hg varies in relation to the measured parameters but seems less for Al than for Hg. While neurotoxicity of environmental Hg (mainly fish methyl-Hg, MeHg) is associated with neurobehavioral outcomes in children, environmental Al is not associated, except in certain clinical conditions. Therefore, the issues of their neurotoxic effects (singly or combined) are discussed. In the infant (up to six months) the organic-Hg and Al body burdens from a full TCV schedule are estimated to reach levels higher than that originating from breastfeeding or from high aluminum soy-based formulas. Despite worldwide exposure to both Al and Hg (inorganic Hg, MeHg, and Thimerosal/EtHg), our knowledge on this combined exposure is insufficient to predict their combined neurotoxic effects (and with other co-occurring neurotoxicants).

Aluminum in vaccines: Does it create a safety problem?

For almost a century, aluminum (Al) in the form of Al oxyhydroxide (a crystalline compound), Al hydroxyphosphate (an amorphous Al phosphate hydroxide), Al phosphate, and Al potassium sulfate has been used to improve the immunogenicity of vaccines. Al is currently included in vaccines against tetanus, hepatitis A, hepatitis B, human papillomavirus, Haemophilus influenzae type b, and infections due to Streptococcus pneumoniae and Neisseria meningitidis. Official health authorities consider the inclusion of Al in most of the presently recommended vaccines to be extremely effective and sufficiently safe. However, the inclusion of Al salts in vaccines has been debated for several years because of studies that seem to indicate that chronic Al exposure through vaccine administration can interfere with cellular and metabolic processes leading to severe neurologic diseases. Children, who in their first years of life receive several vaccine doses over a reduced period of time, would be most susceptible to any risk that might be associated with vaccines or vaccine components. The main aim of this paper was to discuss the data presently available regarding Al neurotoxicity and the risk for children receiving vaccines or other pharmaceutical preparations containing Al. Analysis of the literature showed that no apparent reason exists to support the elimination of Al from vaccines for fear of neurotoxicity. The only problem that deserves attention is the suggested relationship between Al oxyhydroxide-containing vaccines and macrophagic myofaciitis or myalgic encephalomyelitis/chronic fatigue syndrome. Currently, definitive conclusions cannot be drawn on these risks and further studies must be conducted. Until then, Al remains the best solution to improve vaccine efficacy.

Addressing parents' concerns: do vaccines contain harmful preservatives, adjuvants, additives, or residuals?

Vaccines often contain preservatives, adjuvants, additives, or manufacturing residuals in addition to pathogen-specific immunogens. Some parents, alerted by stories in the news media or information contained on the World Wide Web, are concerned that some of the substances contained in vaccines might harm their children. We reviewed data on thimerosal, aluminum, gelatin, human serum albumin, formaldehyde, antibiotics, egg proteins, and yeast proteins. Both gelatin and egg proteins are contained in vaccines in quantities sufficient to induce rare instances of severe, immediate-type hypersensitivity reactions. However, quantities of mercury, aluminum, formaldehyde, human serum albumin, antibiotics, and yeast proteins in vaccines have not been found to be harmful in humans or experimental animals.

Aluminium in Over-the-Counter Drugs

In the early 1970s, aluminium toxicity was first implicated in the pathogenesis of clinical disorders in patients with chronic renal failure involving bone (renal osteomalacia) or brain tissue (dialysis encephalopathy). Before that time the toxic effects of aluminium ingestion were not considered to be a major concern because absorption seemed unlikely to occur. Meanwhile, aluminium toxicity has been investigated in countless epidemiological and clinical studies as well as in animal experiments and many papers have been published on the subject. It is now commonly acknowledged that aluminium toxicity can be induced by infusion of aluminium-contaminated dialysis fluids, by parenteral nutrition solutions, and by oral exposure as a result of aluminium-containing pharmaceutical products such as aluminium-based phosphate binders or antacid intake. Over-the-counter antacids are the most important source for human aluminium exposure from a quantitative point of view. However, aluminium can act as a powerful neurological toxicant and provoke embryonic and fetal toxic effects in animals and humans after gestational exposure. Despite these facts, the patient information leaflets from European antacids that are available OTC show substantial differences regarding warnings from aluminium toxicity. It seems advisable that all patients should receive the same information on aluminium toxicity from patient information leaflets, in particular with regard to the increased absorption through concomitant administration with citrate-containing beverages and the use of such antacids during pregnancy.

Aluminum toxicokinetics regarding infant diet and vaccinations

Some vaccines contain aluminum adjuvants to enhance the immunological response, and it has been postulated that this aluminum could contribute to adverse health effects, especially in children who receive a vaccination series starting at birth. The pharmacokinetic properties and end-point toxicities of aluminum are presented. In assessing the relevance of dietary and medical aluminum exposure to public health, we estimated infant body burdens during the first year of life for breast milk and formula diets and for a standard vaccination schedule. We then compared those body burdens with that expected for intake at a level considered safe for intermediate-duration exposure. The methodology blends intake values and uptake fractions with an aluminum retention function derived from a human injection study using radioactive 26Al. The calculated body burden of aluminum from vaccinations exceeds that from dietary sources, however, it is below the minimal risk level equivalent curve after the brief period following injection.

Aluminum contents of human milk, cow's milk, and infant formulas

BACKGROUND

Aluminum toxicity is well documented and contamination of milk formulas has been implicated as the source of accumulation in bone and brain tissues. The purpose of the current study was to evaluate the aluminum contents of human milk, cow's milk, and infant formulas.

METHODS

Aluminum contents were determined by atomic absorption spectrometry in samples of human milk in the colostrum, intermediate, and mature stages; infant formulas from eight manufacturers; and various types and brands of commercially available cow's milk.

RESULTS

Mean aluminum concentration was lowest in human milk (23.4 +/- 9.6 microg/l), and did not differ significantly between colostrum, intermediate-stage and mature-stage milk. Mean aluminum concentration was 70 microg/l in cow's milk, and 226 microg/l in reconstituted infant formulas. Aluminum concentrations in infant formulas differed markedly among manufacturers; concentration in milk from one of the manufacturers was particularly high (mean, 551 microg/l; range, 302-1149 microg/l). These values are for milk reconstituted with aluminum-free water under laboratory conditions; formulas prepared with tap water in the University Hospital's infant-feeding unit had even higher aluminum content. Experiments showed that aluminum concentration in the high-aluminum milk could be reduced by more than 70% at the manufacturing stage, by using low aluminum components.

CONCLUSIONS

The results of the present study support the recommendations for infant formula manufacturers to strive to reduce aluminum concentration in their products.

Copper and zinc content in human milk in Croatia

The aim of this paper was to research whether there had been any statistically significant difference in the content of Cu and Zn in human milk depending on the social status of women (refugee and non-refugee), age, number of deliveries, days after delivery, weight gained by nursing women and smoking habits, as well as whether the infants had received sufficient quantities of these elements. The elements were determined by flame atomic absorption spectrometry. The samples were collected in the Clinical Hospital Osijek and Refugee Centre Nabrde, near Osijek, Eastern Croatia. The Cu in human milk ranged from 0.27 mg/l to 1.35 mg/l, and Zn from 0.62 mg/l to 15.0 mg/l. The mean levels of Cu and Zn for each group, formed according to the results of the questionnaire are presented too. Calculated daily dietary intake of these elements accords with the RDA.

Zinc levels in human milk and umbilical cord blood

Zinc levels were determined in human milk and umbilical cord blood samples collected in the Rijeka Clinical Hospital during the period from September 1995 to January 1996. The average concentrations of zinc were 4.98 +/- 2.53 mg/l in breast milk (range: 1.69-11.60 mg/l) and 1.18 +/- 0.21 mg/l in umbilical cord blood (range: 0.87-1.91 mg/l). Results of group comparisons regarding mothers' age, parity, residence and smoking habits indicate that parity affected Zn levels in both, breast milk and umbilical cord blood, with higher content found in primiparae. Younger mothers (aged < or = 25 years) also had higher levels of Zn in breast milk compared to those whose age was > 25 years. Residence and smoking habits did not seem to have any impact on Zn concentrations in biological tissues studied. A weak association between umbilical cord blood Zn levels and anthropometric measurements of newborns, like birthweight and head circumference, is also observed.