An Evaluation of Fish Tissue Monitoring Alternatives for Mercury and Selenium: Fish Muscle Biopsy Samples Versus Homogenized Whole Fillets

Fish contaminant studies with human health protection objectives typically focus on muscle tissue, recognizing that fillets are the commonly consumed tissue fraction. Muscle biopsy punch sampling for mercury analysis has recently been used as an alternative to harvesting fish for fillets; however, there is limited information comparing fillet plug results to whole fillet results. This study was conducted to address that data gap and to test the applicability of plugs for monitoring associated with United States Environmental Protection Agency’s fish tissue-based mercury and selenium water quality criteria. The mercury phase included 300 fillet homogenates and 300 field-extracted plug samples from 60 fish, and the selenium phase included 120 fillet homogenates and 120 plugs from 30 fish. Both phases showed that there were no statistically significant differences between fillet plug and homogenized fillet results at the community level; however, a selenium plug monitoring alternative must employ a sufficiently sensitive analytical method and consider total solids. Plug and fillet sampling alternatives have inherent advantages and disadvantages. Fillet sampling provides sufficient mass to consider multiple contaminants but requires fish to be harvested. Plug sampling only provides adequate mass for a single analyte but may allow fish survival, although additional research is needed on survival following plug removal.

Implementation of mercury biomonitoring in German adults using dried blood spot sampling in combination with direct mercury analysis

Venous blood is a preferred matrix for the determination of total mercury (Hg) in human biomonitoring but has some drawbacks such as the requirement for an uninterrupted cold chain for transport and storage and the need of medical personnel for sample collection. Therefore, we tested and implemented a simpler and less expensive method for measuring Hg in human blood using dried blood spots (DBS). For method development, we investigated the influence of different storage conditions (temperature, storage vessel, time) on DBS samples. For method validation, we compared DBS and venous blood and investigated whether DBS sampling is suitable for measuring Hg in the general population in countries with low Hg exposure such as Germany. Based on our results, we found that pre-cleaned glass tubes were most suitable for storage of DBS samples, as this allowed the samples to remain stable for at least 4 weeks even at high temperatures (40 °C). When comparing venous blood and DBS, a very good correlation (r = 0.95, p < 0.01, Spearman-Rho) and high precision of DBS (mean relative standard deviation 8.2% vs. 7.2% in venous blood samples) were observed. Comparing the recoveries of both matrices in different concentration ranges, the variation of the recoveries decreases with increasing Hg concentration. The mean recoveries also decreased with increasing Hg concentration. Overall, we found comparable results for DBS and venous blood using direct Hg analysis. Furthermore, we demonstrated that DBS are suitable for Hg biomonitoring in the general population in Germany and improved the storage conditions for the DBS.

Molecular Identification of Hg-Resistant Bacteria and Their Potential in Reducing Mercury Contamination

The aim of this research was to obtain and determine the identity of Hg-resistant bacteria in soil contaminatedwith gold processing waste and test its ability to reduce mercury contamination. Soil samples as a source of Hgresistant bacterial isolates were obtained from the gold processing location in Ilangata Village, Anggrek District,North Gorontalo Regency. The research was conducted at the Microbiology Laboratory, Department of Biology,Faculty of Mathematics and Natural Sciences. Mercury analysis was carried out at the Laboratory of FisheriesProduct Quality Development and Testing (LPPMHP), Gorontalo Province, and bacterial identification wascarried out at the Hasanuddin University Medical Research Center Research Unit. The parameters observed werethe types of Hg resistant bacteria and the ability of the bacteria to reduce mercury contamination. The resultsshowed that there were four bacterial isolates on the soil contaminated with 4.5 ppm mercury, which were namedILb01, ILB02, ILb03, and ILb04. Molecular identification showed that ILb01 was closely related toStenotrophomonas sp. SB67 and ILb02 close to Enterobacter cloacae strain CM 1, these strains were not resistantto mercury contamination; while ILb03 which is similar to strain BS0591 and ILb04 which is similar to BacteriumBacillus albus strain SQ30 16S could be resistant and was able to reduce mercury contamination by 99% at 10ppm levels. Key words: heavy metals, Hg-resistant bacteria, molecular identification, mercury

Theoretical and practical aspects in determining the current geochemical status of the Crimean peninsula and anthropogenic risk to public health

&lt;p&gt;The implementation of basic principles of medical and ecological monitoring programs in Crimea previously reported in EGU proceedings consists of determining the content of a wide range of toxic, essential and rare earth elements in various biological substrates: soil, plants, water, human body. Biosubstrates are sampled in different locations with contrast natural and anthropogenic conditions: urbanized-rural, industrial-agricultural, natural resources. Lichens and poplar leaves are used as indicators of environmental contamination, particularly atmospheric pollution; liquid precipitation is used as an indicator showing the negative impact of air pollution on ecosystems; hair is used as an indicator of the total body intake of chemical elements. The update of databases, on some of the territories (Simferopol, Sevastopol, geographical regions with different soil characteristics, etc.) with regard to some of the elements (mercury, lead, cadmium, selenium, etc.) at this stage allowed to determine their biogeochemical status in conditions of intensive growth of anthropogenic load in recent years, and to compare it with the elemental status of the humans living in this territory. The databases for other types of territories continue to be extended, the relationship between morbidity to estimate of the environmental burden of disease for environmentally determined diseases (neurodegenerative, endocrine, respiratory, etc.) and chemical load on the territories, based on USEtox model; the functional state of target systems (nervous, immune, cardiovascular) and level of chemical elements in the human body and the overall elemental imbalance, is established. This has provided us with a degree of understanding on how the degree of population and individual health risk could be determined.&lt;/p&gt;&lt;p&gt;Mercury analysis was funded by RFBR according to the research project &amp;#8470; 18-29-24212\19 entitled &amp;#8220;Development of neutralization of mercury-containing waste without heating and the formation of wastewater&amp;#8221;, 2018&amp;#8211;2021 years; elemental composition was possible to determine due to RFBR project &amp;#8470; 18-45-920042\20 entitled &amp;#8220;Bioecological monitoring of heavy metals at board of Black Sea of Crimea&amp;#8221;, 2018&amp;#8211;2020 years. Physiological part of research was possible to accomplish due to funds by the V.I. Vernadsky Crimean Federal University (Project No VG2019/15, &amp;#1040;&amp;#1040;&amp;#1040;&amp;#1040;-&amp;#1040;20-120012090158-7).&lt;/p&gt;

Implementation of Mercury Biomonitoring in German Adults using Dried Blood Spot Sampling in Combination with Direct Mercury Analysis

ABSTRACTVenous blood is a preferred matrix for the determination of total mercury (Hg) in human biomonitoring but has some drawbacks such as the requirement for an uninterrupted cold chain for transport and storage and the need of medical personnel for sample collection. Therefore, we tested and implemented a simpler and less expensive method for measuring Hg in human blood using dried blood spots (DBS). For method development, we investigated the influence of different storage conditions (temperature, storage vessel, time) on DBS samples. For method validation, we compared DBS and venous blood and investigated whether DBS sampling is suitable for measuring Hg in the general population in countries with low Hg exposure such as Germany. Based on our results, we found that pre-cleaned glass tubes were most suitable for storage of DBS samples, as this allowed the samples to remain stable for at least four weeks even at high temperatures (40°C). When comparing venous blood and DBS, a very good correlation (r=0.95, p<0.01) and high precision of DBS (mean relative standard deviation 8.2% vs. 7.2% in venous blood samples) were observed. Comparing the recoveries of both matrices in different concentration ranges, the scattering of the recoveries decreases with increasing Hg concentration. The same applies to the mean recoveries. Overall, we found comparable results for DBS and whole blood using direct Hg analysis. Furthermore, we demonstrated that DBS are suitable for Hg biomonitoring in the general population in Germany and improved the storage conditions for the DBS.

Characteristics of Micro/Nano Pores and Hydrocarbon Accumulation in a Continental Shale Oil Reservoir—A Case Study of the Lucaogou Formation in the Jimsar Sag, Junggar Basin, Northwest China

This paper comprehensively studies the micro- and nanometer-scale pore characteristics and structure of the Lucaogou Formation shale oil reservoir in the Jimsar Sag using high-pressure mercury analysis, field emission scanning electron microscopy and nano-CT scanning technology. In addition, the occurrence states of crude oil in pores are analyzed combined with macro–micro characteristics. The results show that there are various reservoir types; the main reservoir pore structure is on the micron and nanometer levels, with other void spaces including intergranular pores, interparticle dissolution pores, intercrystalline pores and microfissures. Nanopores are generally oil-bearing and mostly in the adsorption state, which changes the traditional understanding that micron pores are the only microscopic pores in the reservoir and confirms that shale oil exists in ‘sweet spots’ and mud-shale sections of the Lucaogou Formation.