Verteilung chemischer Elemente in der Nahrung und Milch stillender Mütter

Goal and Scope

The transfer of various chemical elements from maternal food into human milk was investigated. Transfer factors (hereafter TF) food/mother’s milk were taken to represent those nuclides pertinent to radiation protection in order to estimate possible radioactive burdens of breast-fed babies.

Methods

A total of 23 mothers, mainly from the Euroregion Neisse (PL, CZ, D; all being in their mature phases of lactation), took part in this study (1998–2001), for time periods between two to eight weeks (8805 samples were analyzed). The diurnal uptake of elements was determined by the duplicate method.

Results and Conclusions

TF values determined for Ag, Au, Ba, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, I, La, Mn, Mo, Nb, Ni, P, Pb, Ra, Rb, Re, Ru, Sb, Sr, Te, Th, Ti, U_o, Y, Zn, Zr were theoretically analyzed with the following result: metal ions transfer into mother’s milk mainly in coordinated states (i.e. bound to anionic ligands), with TF values which increase according to complex stabilities. Therefore it can be assessed that neither Cd nor Ba, both forming only weak complexes, pose hazards to breastfed children.

Outlook

There are relationships between transfer factors pertaining to certain elements and the amounts of others consumed by the mother; i.e. (changes in) consumption of one element influence the transfer towards women’s milk of another element. Accordingly, strategies can be developed to keep off hazardous substances — including fissiogenic radionuclides — from milk which is far more efficient than traditional isotopic dilution; however, iodide tablets are useful here, too.     

Erprobung und Erfolgskontrolle eines Phytoremediationsverfahrens zur Sanierung Sprengstoff-kontaminierter Böden

The final article of a series of three evaluates the in situ-remediation of TNT(trinitrotoluene)-contaminated soil from ‘Werk Tanne’. The multidisciplinary approach allows a differentiated assessment. Grading with large-scale machinery leads to a depletion of TNT for almost 90% within the first 6 months, while ADNT(amino-dinitrotoluene)-content decreases more or less steadily over 1,5 years. Grading reduces the heterogenous distribution of the contamination only slightly. Results from field-monitoring and biotest-battery indicate residual toxicities of ecotoxicological relevance and a reduced capacity for biological regeneration, in comparison with the uncontamined site. Mycorrhized plants safe-guard the site and improve the soilecological conditions. Their role in reducing lower level residual toxicity requires further investigation. There is need for future research (1) on the dynamics and mechanisms of the initial decrease of TNT followed by stagnation, (2) on the fate of the primary metabolites, (3) on long-term effects of the phytoremediation, and (4) on the establishment of the complex monitoring for routine work.     

Environmental impacts of a large-scale incinerator with mixed MSW of high water content from a LCA perspective

Large-scale incinerators are applied widely as a result of the heavy burden of municipal solid waste(MSW) generated, while strong opposition is arising from the public living nearby. A large-scale working incineration plant of 1500 ton/day was chosen for evaluation using life cycle assessment. It was found that the corresponding human toxicity impacts via soil(HTs), human toxicity impacts via water(HTw) and human toxicity impacts via air(HTa)categories are 0.213, 2.171, and 0.012 personal equivalents(PE), and global warming(GW100)and nutrient enrichment(NE) impacts are 0.002 and 0.001 PE per ton of waste burned for this plant. Heavy metals in flue gas, such as Hg and Pb, are the two dominant contributors to the toxicity impact categories, and energy recovery could reduce the GW100 and NE greatly. The corresponding HTs, HTw and HTa decrease to 0.087, 0.911 and 0.008 PE, and GW100 turns into savings of- 0.007 PE due to the increase of the heating value from 3935 to5811 k J/kg, if a trommel screener of 40 mm mesh size is used to pre-separate MSW. MSW sorting and the reduction of water content by physical pressure might be two promising pre-treatment methods to improve the combustion performance, and the application of stricter standards for leachate discharge and the flue gas purification process are two critical factors for improvement of the environmental profile identified in this work.     

Greenhouse gas emission and its potential mitigation process from the waste sector in a large-scale exhibition

As one of the largest human activities, World Expo is an important source of anthropogenic Greenhouse Gas emission (GHG), and the GHG emission and other environmental impacts of the Expo Shanghai 2010, where around 59,397 tons of waste was generated during 184 Expo running days, were assessed by life cycle assessment (LCA). Two scenarios, i.e., the actual and expected figures of the waste sector, were assessed and compared, and 124.01 kg CO₂-equivalent (CO₂-eq.), 4.43 kg SO₂-eq., 4.88 kg NO₃^--eq., and 3509 m³ water per ton tourist waste were found to be released in terms of global warming (GW), acidification (AC), nutrient enrichment (NE) and spoiled groundwater resources (SGWR), respectively. The total GHG emission was around 3499 ton CO₂-eq. from the waste sector in Expo Park, among which 86.47% was generated during the waste landfilling at the rate of 107.24 kg CO₂-eq., and CH₄, CO and other hydrocarbons (HC) were the main contributors. If the waste sorting process had been implemented according to the plan scenario, around 497 ton CO₂-eq. savings could have been attained. Unlike municipal solid waste, with more organic matter content, an incineration plant is more suitable for tourist waste disposal due to its high heating value, from the GHG reduction perspective.     

两种微藻胞外分泌物与NO2-、NO3-对2，4-D光解的影响

在模拟太阳光照射下,利用旋转式光化学反应装置,研究了海水小球藻(Chlorella vulgaris)和新月菱形藻(Nitzschia closterium)的胞外分泌物(EOM),以及分别在NO-2或(和)NO-3共存条件下对2,4-二氯苯氧乙酸(2,4-D)光解的影响.实验结果表明,2,4-D在海水小球藻和新月菱形藻EOM及分别在NO-2、NO-3共存下的光解过程均符合准一级动力学反应.研究发现,2,4-D的光解速率随海水小球藻和新月菱形藻EOM浓度的增加而减小,表明这两种微藻EOM可抑制海水中2,4-D的光解.当在微藻EOM溶液中分别加入不同浓度的NO-2或NO-3后,微藻EOM对2,4-D光解的抑制作用减弱,且随着NO-2和NO-3浓度的增加,2,4-D光解速率明显增加.特别是当微藻EOM与NO-2或NO-3三者共存时,可进一步促进2,4-D的光解.