Isotopes in Environmental and Health Studies最新文献

In the Himalayas, the lives and livelihoods of millions of people are sustained by water resources primarily depending on the moisture brought by Western Disturbances and Indian Summer Monsoon. In the present study, a network of 12 precipitation stations was established across the Kashmir Valley to understand the spatial and meteorological factors controlling precipitation isotopes. Temperature and relative humidity are dominant meteorological factors, whereas altitude, proximity to forest canopy, land use/land cover, windward and leeward sides of the mountains are the main physical factors influencing precipitation isotopes. The study suggests that the Mediterranean Sea and nearby water bodies along with continental recycling are the dominant sources of moisture from October to May, while the Arabian Sea, Bay of Bengal and continental recycling are the main sources of moisture from June to September. However, some precipitation events from October to May collect moisture from the Arabian Sea and some precipitation events from June to September collect moisture from the Mediterranean Sea. The occasional passage of Western Disturbances in summer merging with the Indian Summer Monsoon yields heavy to very heavy precipitation. The study provides a better understanding of complex spatial and meteorological phenomena controlling precipitation isotopes across the Western Himalayas.

This paper presents a detailed review of the use of ⁸⁷Sr/⁸⁶Sr isotope systematics for wine provenance studies. The method is based on the principle that the Sr isotope ratio in wine reflects that of the labile fraction of the vineyard soil from which the wine is produced. The review encompasses ⁸⁷Sr/⁸⁶Sr data from wine samples published between 1993 and 2021 from terroirs in 22 different countries. The analytical procedures and techniques adopted by the different authors and the range of isotope ratios obtained in the different studies are discussed and evaluated. This study provides a bibliometric analysis of the ⁸⁷Sr/⁸⁶Sr isotope approach for wine authentication at different scales. Although limitations are evident when implemented at large (global) scales, we demonstrate that the ⁸⁷Sr/⁸⁶Sr isotope tracing technique remains a powerful and reliable tool for determining the geographical origin of wine when combined with detailed knowledge of the geological and soil characteristics of the substrata. For example, this combination of data allows the wines grown in the volcanic soils of Central and Southern Italy to be unambiguously fingerprinted. We present a detailed protocol for the application of the Sr isotope technique to wine authentication.

This study aimed to evaluate natural radioactivity levels and hazards of radionuclides ²³²Th, ²²⁶Ra and ⁴⁰K in soil samples taken from 15 locations in the Lega Dembi gold mining, Oromia, Ethiopia, using gamma-ray spectroscopy coupled with an HPGe detector. It was observed that the respective mean specific activities for ²²⁶Ra, ²³²Th and ⁴⁰K determined in the mining site were 23.87 ± 0.7, 52.5 ± 1.8 and 391.62 ± 11.35 Bq/kg, and 8.89 ± 0.4, 13.83 ± 0.6 and 423.68 ± 9.5 Bq/kg in the living areas. The specific activity of ²³²Th was above the permissive limit in the mining site, while for ²²⁶Ra and ⁴⁰K were within the limit. The specific activity of ⁴⁰K in the living area was observed to be above the permissive limit. The calculated value of radiation hazards parameters; radium equivalent activity (Ra_eq), internal and external hazards indices (H_in) and (H_ex), the mean annual effective dose (AED), and gamma representative indices (I_γ) were within permissively limit. The mean absorbed dose rate in the mining site was above the recommended safety limit. The total annual gonadal dose equivalent value was found to be 494.8 ± 8.7 µSv/a in the mining site. This value was also above the permissively.

There is an increasing global demand for regional and organic produce. However, the growth of these markets depends on consumers' trust. Thus, novel methods must be developed to aid the verification of the origin of produce. We built on our previous study to identify the geographical origin and production method of animal-derived food products. Thirty-samples of eggs, 99 of milk, 34 of beef, and 62 of pork were collected from different regions in central Germany and analysed for their stable isotopic composition. The analysis followed a single-variate authentification approach using five isotope signatures, δ¹⁸O, δ²H, δ¹³C, δ¹⁵N, and δ³⁴S. The best-performing indicators for verification of the geographical origin were δ¹⁵N and δ³⁴S for beef; δ¹⁸O, δ²H, and δ¹³C for milk, and δ²H and δ¹³C for pork. These tracers indicated statistically significant differences among regions with the exception of pork; the results recorded for eggs were inconclusive. It was possible to distinguish between production methods by means of δ¹⁵N and δ³⁴S (beef); all five tracers (eggs), and δ¹³C, δ¹⁵N, and δ³⁴S (milk). This study demonstrated how the analysis of stable isotopes can be employed to determine the geographic region of origin and production method of animal-derived products in Germany.

After the atmosphere, the ocean is the most well-mixed and homogeneous global geochemical reservoir. Both physical and biological processes generate elemental and isotope variations in seawater. Contrasting geochemical behaviors cause elements to be susceptible to different fractionation mechanisms, with their isotopes providing unique insights into the composition and evolution of the ocean over the course of geological history. Supplementing the traditional stable isotopes (H, C, O, N, S) that provide information about ocean processes and past environmental conditions, radiogenic isotope (Sr, Nd, Os, Pb, U) systems can be used as time markers, indicators of terrestrial weathering, and ocean water mass mixing. Recent instrumentation advances have made possible the measurement of natural stable isotope variations produced by both mass-dependent and mass-independent fractionation for an ever-increasing number of metal elements (e.g. Li, B, Mg, Si, Ca, V, Cr, Fe, Ni, Cu, Zn, Se, Mo, Cd, Tl, U). The major emphasis in this review is on the isotopic composition of the light elements based on a comparatively large literature. Unlike O, H and S, the stable isotopes of C, N and Si do not have a constant isotopic composition in the modern ocean. The major cations Ca, Mg, and Sr fixed in carbonate shells provide the best proxies for reconstruction of the composition of the ocean in the past. Exhibiting large isotope enrichments in ocean water, B and Li are suitable for the investigation of water/rock interactions and can act as monitors of former oceanic pH. The bioessential elements Zn, Cd, and Ni are indicators of paleoproductivity in the ocean. Characteristic isotope enrichments or depletions of the multivalent elements V, Cr, Fe, Se, Mo, and U record the past redox state of the ocean/atmosphere system. Case studies describe how isotopes have been used to define the seawater composition in the geological past.

Radium-226 detection in sediment samples is generally executed by means of gamma-ray spectrometry. Data evaluation relies (besides the 186.2 keV ²²⁶Ra gamma peak) on the combined analysis of major gamma peaks that are produced by the short-lived radon (²²²Rn) daughters ²¹⁴Pb and ²¹⁴Bi. Precondition for this detection approach is equilibrium decay of all members of the decay chain between ²²⁶Ra and ²¹⁴Bi. In closed systems, this equilibrium is reached after about five half-lives of ²²²Rn (19 days). However, a closed system can only be guaranteed if the capsule which contains the sample prevents diffusive escape of radon. Such radon-tightness cannot be guaranteed for a wide range of plastic materials. Due to its polymer structure, plastic material generally tends to allow radon diffusion and hence radon loss from the sample resulting in a disturbance of the required decay equilibrium. The paper introduces an approach that allows quantifying radon loss from sample capsules by direct radon measurements using mobile radon detection equipment. The experimental findings are supported by theoretical considerations. An examined alternative approach based on the offset of the 186.2 keV data point from an efficiency function that is calculated exclusively from short-lived radon progeny peaks in the gamma-ray spectrum did not prove to be applicable due to a lack of supporting peaks in the low-energy section of the spectrum.

A novel simplified method is presented for the estimation of the metabolism of plasma proteins (albumin, fibrinogen, α, β and γ-globulin, glycoprotein) with regard to the whole body protein metabolism in a young male volunteer (22 years, 81 kg body mass). This method is based on multiple oral administration of [¹⁵N]glycine followed by measurement of ¹⁵N in plasma proteins, total free amino acids, urea and excreted urinary N. The fractional synthesis rate of albumin was estimated to 6.8 % d^-1 based on amino acids and 3.3 % d^-1 based on urea, respectively. The fractional synthesis rate of the other plasma proteins ranged from 4.3 % d^-1 (γ-globulin) to 26.4 % d^-1 (α-globulin, fibrinogen). We conclude that the simplified approach using [¹⁵N]glycine provides results which are similar to results based on the simultaneously applied ¹³¹I-human serum albumin technique as 'gold standard' and to those reported in literature. The compartmental analysis considering comprehensive tracer kinetic data ensures reliable data treatment and enables statistical evaluation. The analytical effort is minimal because the ¹⁵N enrichment of plasma protein after chemical digestion may be directly used. Therefore, the novel stable isotope ¹⁵N method is suitable for studies in clinical and nutritional research and practice.

This study assessed radon (²²²Rn) levels in drinking water sources in the Nizampur basin and their potential health risks for the local community. We analyzed 48 water samples on-site using RAD7. Additionally, we measured pH, temperature (T), total dissolved solids (TDS), redox potential (ORP), and electrical conductivity (EC) with a multiparameter analyzer. Results showed pH, T, TDS, ORP, and EC ranging from 7.2 to 8, 17 to 26 °C, 333 to 1130 mg/l, -56 to 284 mV, and 469 to 2370 µS/cm. ²²²Rn levels varied significantly (0.7-107 Bq/l, mean 23 ± 21, median = 17 Bq/l), with about 65 % exceeding the EPA's limit of 11.1 Bq/l, indicating health risks likely due to local geological conditions. The annual effective doses for ingestion (Ew_Ing) were 0.87 ± 0.01, 0.35 ± 0.006, and 0.13 ± 0.002 µSv/a for adults, infants, and children, respectively. Exposure risk via the inhalation (Ew_Inh) route ranged from 1.75 to 270 µSv/a, with the highest risk in infants, followed by children and adults. Inhalation was the primary exposure route for all age groups. Further, spatial distribution maps and hotspot analysis suggested that the central region characterized by high structural deformation and favorable geology for radon emanation was the area of concern in terms of health risks.

Stable isotope (δ²H, δ¹³C) measurements of wing tissue have been used to determine the natal geographic origin of migrant monarch butterflies that overwinter in Mexico. This study examines the possibility of using δ¹³C and δ¹⁵N to identify the milkweed habitat used by monarchs in their natal region. Milkweeds were common in corn and soybean fields before herbicide use led to their extirpation around 2006, and the loss of those milkweeds has been proposed as a reason for the monarch population decline. If crop-field monarchs can be identified, then historical samples of monarchs could be examined to test that hypothesis. The δ¹⁵N and δ¹³C values of leaves from milkweeds growing in corn fields, soybean fields and non-agricultural habitats were examined as well as monarchs that were raised on those leaves. There were no δ¹⁵N values for leaves or monarchs that were distinctive for crop fields. Milkweeds in corn fields, and monarchs that were raised on those milkweeds, were found to have δ¹³C values distinctly lower than those of other habitats and unlike those of locations within the summer breeding range. Thus, it should be possible to identify monarchs that came from cornfields in samples of overwintering monarchs made before ca. 2006.