Agnieszka Zielińska

Reference values for hair minerals of Polish students.

In the present work, reference values for the content of elements in human hair were elaborated. The population chosen for the study was a group of students in Polish urban area, which served as a representative group of a population of 20 years old individuals living in Europe. The content of 36 elements (essential (B, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, P, S, Si, Sn, V, Zn), toxic (Al, As, Cd, Hg, Ni, Pb, Sb, Tl) elements and others (Ag, Ba, Bi, Ce, La, Li, Rb, Sr, Ti, Y, Zr)) was determined in hair sampled from 117 subjects. Hair were digested with nitric acid in microwave oven in closed Teflon bombs and underwent multielemental analysis for the content of macroelements by ICP-OES and for micro- and trace elements by ICP-MS. Reference ranges were determined and considered as the values between 10th and 90th percentile. It was assumed that the values of the extreme low and high 10% in the population reflected mineral imbalance. In the population, a group of females and males was distinguished, and also a group of women which tinted their hair was separated. This enabled to point out the differences in hair mineral content between genders and for tinted and non-tinted hair. Statistical significance of differences was found for several elements, for which separate reference values were elaborated. This concerned the following elements: Ba, Ca, Cu, K, La, Mg, Mn, Si, Sr and Ti. In the interpretation of the level of these elements it is necessary to take into consideration both sex and artificial coloring. Also ratios between elements were evaluated - between nutritive (Ca/Mg, Ca/P, Na/K, Zn/Cu) and nutritive vs. toxic (Zn/Cd, Zn/Pb). In this case the differences were detected only for Ca/P ratio. This shows that perhaps in the future, inter-element ratios rather than the absolute levels of elements would be considered for the interpretation of the results of mineral analysis of hair.

Inter-relationship between elements in human hair: the effect of gender.

The aim of the present work was to examine the inter-relationship between elements in human hair depending on gender. In the whole population, the following groups of correlated elements were identified: alkaline earth metals (Ba, Ca, Mg, Sr), major microelements (Cu, Mn, Si, Zn) and La, Ti. In the subpopulation of males, the (Ag, Al, As, Fe) group was additionally included, whereas in the group of females (Ag, Al, Fe, Zr) was included. The group of alkali metals (Li, Na, K) and P was particularly visible in the group of males. In the group of females correlations among (Al, Co, Fe, K, Ti) were stronger than in males. In both sexes correlations between Mo, B and V (in females additionally Bi was present) and Bi-Co were found. Only in hair of males (Cd, Fe, Mn) and (Cu, Na, P) were detected, and the group of (As, Co, Cr, Fe, K, Ti) was detected only in females.

Effect of macroalgae enriched with microelements on egg quality parameters and mineral content of eggs, eggshell, blood, feathers and droppings

This study presents results obtained from feeding experiment on laying hens, which were fed with the diet supplemented with two marine macroalgae: Enteromorpha prolifera and Cladophora sp., enriched with microelements [Cu(II), Zn(II), Co(II), Mn(II), Cr(III)]. The applicability of the preparation was tested on five experimental groups of laying hens and one control group. In the control group, microelements were supplemented in the inorganic form, whereas in experimental groups, Cu, Zn, Co, Mn and Cr were replaced by macroalgae enriched with a given microelement ion. During feeding experiment, weight of laying hens, weight of eggs, eggshell thickness and mineral content of blood, feathers, droppings, eggs content (separately yolk and egg white) and eggshell were measured. Also egg number was counted and microclimate (temperature and relative humidity) was monitored. Supplementing bio-metallic feed additives to the diet of laying hens resulted in higher microelement transfer to eggs and enhanced the colour of yolk. It was also found that the presence of Enteromorpha prolifera and Cladophora sp. in laying hens diet influenced advantageously eggs weight, eggshell thickness as well as body weight of hens. On the basis of these results, it could be concluded that Enteromorpha prolifera and Cladophora sp. enriched with microelement ions could be potentially used as mineral feed additives in laying hens feeding.

The effect of dietary habits on mineral composition of human scalp hair.

In the present work, hair mineral analysis of 117 individuals was carried out. The subjects were asked to fill a questionnaire concerning their dietary habits. The content of minerals in hair was determined by ICP-OES (macroelements) and ICP-MS technique (micro-, toxic and other trace elements). The results were elaborated statistically by Statisticaver. 8.0. It was found that consuming highly processed food causes increased levels of e.g. Na and P in hair, intake of slimming preparation resulted in increased content of Al, Cr, Ti, taking in laxative agents caused lower level of Pb (this element was probably eliminated by other excretory routes). Individuals which declared the use of analgesic agents had more Si in their hair. Drinking coffee was related with higher level of Al, Ni, S and Ti and lower Pb in hair. Drinking tea caused reduction in the level of Hg. These results show that hair mineral content reflects exposure of elements from the diet.

Evaluation of growth yield of Spirulina (Arthrospira) sp. in photoautotrophic, heterotrophic and mixotrophic cultures

In microbial cultures, both cellular growth rate and yield (defined as the degree of substrate conversion into the biomass) are important. Although effect of culture conditions on growth kinetics has been well documented for various microbial strains, there is almost no literature concerning the effect of environmental conditions on growth equilibrium, expressed as biomass yield coefficients from substrate. The present paper discusses the effect of culture conditions: irradiance (physical substrate) and glucose concentration (chemical substrate) on biomass yield coefficients from two chemical substrates: glucose and nitrate-nitrogen in photoautotrophic, heterotrophic and mixotrophic culture of blue-green alga Spirulina (Arthrospira) sp. The efficiency of substrates incorporation into the biomass can be precisely determined only if the elemental composition of the biomass is known. The experimental results showed that culture conditions had a substantial influence on biomass yield coefficients (biomass yield from glucose and nitrate-nitrogen). It was found that, the increase of irradiance favoured increase of biomass yield coefficient from both, glucose and nitrate-nitrogen. However, in the case of yield from nitrogen in mixotrophic culture, the effect was opposite. The effect of glucose concentration was different: the higher the initial glucose concentration, the lower the biomass yield coefficients from chemical substrates.

Exposure to metals from orthodontic appliances by hair mineral analysis

The aim of the present work was to investigate the exposure of patients to metals released from orthodontic appliances in situ. The paper reports the results of biocompatibility studies of orthodontic appliances by an in vivo method using hair sampled from the group of patients (N = 28) and a control group (N = 18). The mean content of metals (Ni, Cr, Mn, Fe) in hair that were hypothesized to be systemically absorbed from stainless steel, was provided. The highest difference between the groups was found for Ni (39% higher level in hair of patients), Mn (18%), Fe (4.1%), Cr (2.5%), as calculated by a new dimensionless metal release coefficient (α). The second coefficient defined in the present work (β) corresponded to the difference in the mean content of elements between the groups. The coefficient was the highest for Fe, subsequently Ni, Mn and Cr. None of the differences was statistically significant. For each group and a given element, ranges between 10th and 90th percentile were determined. The upper value of the range differed the mostly between the groups for Ni (82.5%) showing that stainless steel of orthodontic appliance can be the source of exposure to this element. The difference was also identified for Mn (26.5%). For Cr and Fe, the lower value of the range was elevated. It was noted that 22% of patients undergoing orthodontic treatment had elevated levels of Ni in hair. A correlation matrix between the content of the elements in hair was calculated. Statistically significant correlations were found between Cr and Fe, showing similar sources of exposure. Multiple regression analysis showed the dependence of Ni content (dependent variable) on the level of Co and Mg (synergism) and V (antagonism).