Are you asking, What is the minimum detectable activity?

o in the project Increase of uranium in human urine samples Feb 2017 - June 2017

Fisenne et al. - 1987 - The daily intake of U, Th and Ra.pdf. There are air concentrations given...

I can send you this article if you give me your email address. Too complicated to attach it here on RG. Mine is [email protected].

Hello, Iam also intested to this article, can i have a coppy?

That obviously is a very important question. Unfortunately, there is no straight forward answer since there is no reference data on CPMET-provoked urine but only on spontaneous urine / 24-h-urine.

CPMET Urine gives rather a measure of retained uranium over a longer period of time whereas spontaneous urine reflects more recent burdens of the previous 1-2 weeks (as long as no excessive intoxication occurs which may implicate detectable rises in spontaneous urine for longer periods, even years).

Estimates from spontaneous urine studies indicate absorption rates of 1 % of ingested and 3-5 % of inhaled Uranium depending on age and chemical nature and size of uranium particles a.o..

There is a well documented set of data on spontaneous urine provided by Kurttio et al., Kidney Toxicity of Ingested Uranium From Drinking Water, Am J Kidney Dis 47:972-982.

Since we have one spontaneous urine sample in early uranium episode showing 0.15 µg/L U238 (= +/- 95% percentile) we could estimate the daily uptake using Kurttios data to 20 - 30 µg/day in this early phase of the uranium episode - when ingested via drinking water. For inhaled Uranium the amount in aerosols may be smaller depending on solubility and particle size (smaller, soluble particles have higher absorption rates into circulation and subsequently to kidney and urine).

Estimates of absolute U-uptake from CPMET- provoked urinary Uranium would be speculative at this stage - I could not find any literature on it.

Calculation of relative increases is in so far complicated, that nearly all samples before and after the Uranium Episode did not show U238 above detection limit and could therefore not be quantified exactly using the DDI standard ICP-MS protocoll. One sample of post -UE, however, was analysed for U235/U238 ratios using more sensitive ICP-MS. It contained 0.0385 µg/L U238 . Compared to the average of 0.31 µg/L in the 34 CPMET-samples in Uranium Episode we could estimate an relative increase of retained Uranium for factor 8 compared to background exposure.

Hope that helps - looking forward to having your views.

1 µg U238 = 0.336 pCi

Thank you. I will try to understand what this means. But please, can you tell me what "mcg" means in common SI-units?

just clarified Units in previous anwser

Hassoun, Rula; Schnug, Ewald Julius Kühn-Institut, Institut für Pflanzenbau und Bodenkunde, Braunschweig A statistical evaluation of the contribution of mineral and tap water to the dietary intake of AS, B, Cu, Li, Mo, Ni, Pb, U and Zn by humans Abstract Agriculture is a main contributor to environmental loads of nearly all elements of the periodic table. Mineral fertilizers, especially mineral phosphorus fertilizers, contain significant amounts of elements which affect the environment. The annual average loads of the elements arsenic (As), boron (B), copper (Cu), lithium (Li), molybdenum (Mo), nickel (Ni), lead (Pb), uranium (U) and zinc (Zn) to the entire agricultural land in Germany by the application of phosphorus fertilizers correspond to 38, 1575, 170, 10, 71, 50, 14, 239 and 604 tons, respectively. Some of these elements are essential for plants and higher organisms, for example B, Cu and Mo; others show a significant toxicity for life processes such as As, Pb and U. However, also essential elements such as Cu and Zn are toxic in higher concentrations. There are two major pathways by which elements enter the food chain: either by the uptake into food and forage plants or by leaching in potable ground and surface water bodies. As data on the contribution of drinking water to the total daily intake of these elements are scarce a study was conducted to evaluate the relative significance of mineral and tap waters to the total daily intake of the elements As, B, Cu, Li, Mo, Ni, Pb, U and Zn by humans. Preliminary results of this study are presented.

The necessary U-concentration also depends on the measuring range and on the measuring accuracy of the measuring instrument. Since, in respective host substances occur radioactive nonequilibrium states , the chemical and physical environment has a considerable influence on the measurement result and thus also on possible threshold values of the Uranium concentration.

M.L.