Reliable biological indicator identification and evaluation of tobacco-derived nicotine using an ultra-sensitive gas chromatography-tandem mass spectrometric method.

Several countries have exempted synthetic nicotine from existing regulatory frameworks, resulting in the widespread substitution of synthetic nicotine (SN) in almost all e-cigarette products available. However, it remains uncertain whether the purported synthetic nicotine is indeed genuine SN. There is a need to develop biological indicators and an analytical method that more clearly distinguishes between the two sources. Impurities in neat tobacco-derived nicotine (TDN) were characterized and identified through non-targeted and targeted analysis. Gas chromatography-tandem mass spectrometry (GC-MS/MS) conditions were optimized for detecting biological indicators in e-cigarette products. Nine tobacco-related alkaloids were identified and selected as biological indicators for TDN. A liquid-liquid extraction and GC-MS/MS quantitative method were developed to detect nine biological indicators in e-cigarette products with the limit of quantification ranging from 0.2 to 4.2 µg L-1 using 0.5 mL of e-liquid. This method was applied to 50 e-cigarette brands purchased in the Korean market. The developed method was able to easily and accurately identify the origin of nicotine even using a small amount of e-liquid sample. It is expected that effective e-cigarette regulation will be possible if the nicotine biological indicator and high-sensitivity analysis method developed in this study are used.

Moss as a passive biomonitoring tool for the atmospheric deposition and spatial distribution pattern of toxic metals in an industrial city.

Anthropogenic pollution impacts human and environmental health, climate change, and air quality. Karabük, an industrial area from the Black Sea Region in northern Türkiye, is vulnerable to environmental pollution, particularly soil and air. In this research on methodological aspects, we analyzed the concentrations of six potential toxic metals in the atmospheric deposition of the city using the passive method of moss biomonitoring. The ground-growing terrestrial moss, Hypnum cupressiforme Hedw., was collected during the dry season of August 2023 at 20 urban points. The concentrations of Cr, Cu, Cd, Ni, Pb, and Co were determined in mosses by the ICP-MS method. Descriptive statistical analysis was employed to evaluate the status and variance in the spatial distribution of the studied metals, and multivariate analysis, Pearson correlation, and cluster analysis were used to investigate the associations of elements and discuss the most probable sources of these elements in the study area. Cd and Co showed positive and significant inter-element correlations (r > 0.938), representing an anthropogenic association mostly present in the air particles emitted from several metal plants. The results showed substantial impacts from local industry, manufactured activity, and soil dust emissions. Steel and iron smelter plants and cement factories are the biggest emitters of trace metals in the Karabük area and the primary sources of Cr, Cd, Ni, and Co deposition.

Moss-bag technique as an approach to monitor elemental concentration indoors.

The moss-bag technique has been used for many decades to monitor outdoor pollution. More recently, however, the method has been used to monitor indoor air pollution (IAP), as humans spend the majority of their time indoors. The purpose of the research conducted was to evaluate indoor air pollution using active moss biomonitoring. Pleurozium schreberi moss bags were exposed for two seasons (summer and winter), hanging over tile stoves and coal stoves. The selected elements: Al, Cu, Cd, Co, Pb, Zn, V, Ba, Cr, Fe, Mn, Sr, P, Ni, and S were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and, for Hg, by a direct mercury analyzer. The study found the exposure season affected the concentrations of selected elements in 62.5% of cases, and their source was identified. The average concentrations of Co, Ba, Cr, and Sr were higher, and statistically significant, in winter, after a 12-week exposure period of the mosses, regardless of the type of heating or cooking stove owned. The higher phosphorus concentrations obtained in summer indicate physiological stress caused by unfavorable winter exposure conditions. In the future, the number of species used to assess indoor air pollution should be increased and the range of pollutants expanded, along with the identification of their sources, taking residents' lifestyles into account.

Selected freshwater fish species for assessing the water quality of the lower catchment of the Kelani River, Sri Lanka.

Kelani River is the most polluted river in Sri Lanka and the lower catchment is more polluted than the upper catchment. In the present study, freshwater fish species of the lower catchment of the river were investigated for the use of assessing the water quality. Cast net sampling and identification recorded 34 freshwater fish species from the lower catchment, the majority represented by family Cyprinidae. Fish species richness, diversity indices, distribution, abundance and the regression analysis of fish species with water quality parameters revealed high sensitivity and tolerance of three fish species with certain water quality parameters. Dawkinsia singhala was tolerant to the fluctuations of the chemical parameters of the water, while Rasbora daniconius and Pethia reval were tolerant to the physical parameters. Positive correlations were evident between the ammonium and phosphate concentrations of the water and distribution and abundance of D. singhala, while R. daniconius and P. reval showed positive correlations with turbidity of water and pH value respectively. Furthermore, the study reveals that D. singhala is more suitable for predicting the water quality of urban and peri-urban locations of the river, while P. reval and R. daniconius are more suitable for assessing the water quality of rural locations. Thus, the present study reveals a strong possibility of using D. singhala, R. daniconius and P. reval, as biological indicators for assessing the variation of water quality of the lower catchment of the Kelani River. However, despite the fact that such a study has been conducted for the first time in Sri Lanka, it is restrained by certain limitations, and seasonal variations of water quality parameters with fish parameters, adaptations inherent to fish species and food availability in different locations combined with long-term monitoring of fish assemblages have not been considered. Future studies investigating these aspects will further enhance the value of the study.

Assessing the Capability of Chemical Ameliorants to Reduce the Bioavailability of Heavy Metals in Bulk Fly Ash Contaminated Soil.

In-situ rehabilitation of fly ash at dumping sites has rarely been addressed for crop production due to growth-related constraints, largely of heavy metal (HM) contamination in soils and crops. Current communication deals with a novel approach to identify a suitable management option for rejuvenating the contaminated soils. In this background, a 60-days incubation experiment was conducted with different fly ash-soil mixtures (50 + 50%, A1; 75 + 25%, A2; 100 + 0%, A3) along with four ameliorants, namely, lime (T1), sodium sulphide (T2), di-ammonium phosphate (T3), and humic acid (T4) at 30 ± 2 °C to assess the ability of different fly ash-soil-ameliorant mixtures in reducing bio-availability of HMs. Diethylenetriaminepentaacetic acid (DTPA)-extractable bio-available HM contents for lead (Pb), cadmium (Cd), nickel (Ni), and chromium (Cr) and their respective ratios to total HM contents under the influence of different treatments were estimated at 0, 15, 30, 45, and 60 days of incubation. Further, the eco-toxicological impact of different treatments on soil microbial properties was studied after 60 days of experimentation. A1T1 significantly recorded the lowest bio-availability of HMs (~49-233% lower) followed by A2T1 (~35-133%) among the treatments. The principal component analysis also confirmed the superiority of A1T1 and A2T1 in this regard. Further, A1T1 achieved low contamination factor and ecological risk with substantial microbial biomass carbon load and dehydrogenase activity. Thus, liming to fly ash-soil mixture at 50:50 may be considered as the best management option for ameliorating metal toxicity. This technology may guide thermal power plants to provide the necessary package of practices for the stakeholders to revive their contaminated lands for better environmental sustainability.

ZIPLAS: Zooplankton Index for Polish Lakes' Assessment: a new method to assess the ecological status of stratified lakes.

Zooplankton is widely recognized as a key component of pelagic ecosystems and forms the basis for major trophic webs. Although zooplankton has often been used as an indicator of trophic state, it has not been included as an obligatory element of the water assessment systems compliant with the Water Framework Directive. This article introduces the Zooplankton Index for Polish Lakes' Assessment (ZIPLAS) as a new method to assess the ecological status of stratified lakes based on the zooplankton community. The ZIPLAS evaluates three aspects of zooplankton communities, namely, taxonomic composition and abundance, diversity of the zooplankton community, and stressor-sensitive species, which are combined into a multimetric index. Following are the metrics used to compose multimetric ZIPLAS: percentage share of the Rotifer species indicative of high trophy in the indicative group's number (IHTROT; %), ratio of Calanoida to Cyclopoida individual numbers (CA/CY), percentage of tecta form in the population of Keratella cochlearis (TECTA; %), Margalef's index (d), and zooplankton abundance (NZOL; ind./L). ZIPLAS responds clearly to eutrophication indicators-the strongest with Secchi disc visibility (Spearman's rank correlation R = 0.86) and slightly weaker with the expressed by total phosphorus (R = -0.74), total nitrogen (R = 0.68) and the catchment pressure expressed by the nutrient loads generated by different types of land use (R = -0.58).

Searching for indicator macroinvertebrate traits in an Afrotropical riverine system: implication for ecosystem biomonitoring and sustainability.

In the past three decades, macroinvertebrate traits have been explored and employed in the biomonitoring of riverine systems globally, but much attention has not been given to the trait-based approach (TBA) in Nigeria. Therefore, in this study, the distribution patterns of macroinvertebrate traits in selected stations exposed to varying degrees of perturbation in River Hadejia, north-western Nigeria, were explored to assess the ecological health of the river. Three stations were selected, representing an increasing gradient of pollution: station 1 > station 2 and station 3, and were used to search for potential indicator traits. Four traits, including body size, respiratory, mobility, and body shape, were selected and classified into 12 trait attributes. The RLQ analysis revealed macroinvertebrates possessing medium and large body sizes, climbing and crawling, tegumental, gills, and aerial: lungs respiratory traits, and streamlined body shape were associated with station 1. Conversely, macroinvertebrates possessing very small and small body sizes, aerial: spiracle and aerial/vegetation, sprawling, swimming, and skating, flattened, spherical, cylindrical, and rhomboidal were mainly associated with stations 2 and 3. In searching for potential indicator macroinvertebrate traits aside from the RLQ analysis conducted, a fourth-corner analysis was further performed, which showed traits including medium and large body sizes, tegumental, and aerial: lung respiratory traits to be sensitive to pollution. Equally, aerial/vegetation, flattened body shape, and very small body size were found to be tolerant of pollution. A more robust trait-based biomonitoring study using more trait classes such as feeding mechanism, food preferences, voltinism, and attachment mechanism is recommended for future study in this region. The study would be helpful in biomonitoring of ecosystem health and enhance the sustainability prowess of the TBA in the studied region.

Reference intervals of systemic immune-inflammation index, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, mean platelet volume to platelet ratio, mean platelet volume and red blood cell distribution width-standard deviation in healthy Han adults in Wuhan region in central China.

Low-grade inflammatory indicators are widely used in the diagnosis and prognosis of different diseases, particularly, in cancers. The establishing of reference intervals (RIs) are necessary to provide baselines for the interpretation and application of the indicators in clinical. A retrospective review was organized to include ostensibly healthy subjects aged >18 years old to establish RIs based on gender and age for systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume-to-platelet ratio (MPV/PLT), MPV and red blood cell distribution width - standard deviation (RDW-SD). Another 5012 healthy persons were included to validate the RIs. The differences among gender, age, and Body Mass Index (BMI) groups were compared to assess their influences on each indicator. A total of 26,242 males and 11,934 females were included. All indicators differed between males and females except NLR. Compared with males, the values of SII, PLR, MPV and RDW-SD were higher while MPV/PLT lower in females. The values of SII, NLR and PLR increased with age in females between 18 and 50 years old, declined in 51-60 years old group, then increased with age again. Values of MPV/PLT and RDW-SD increased with age. The values of SII increased with BMI while PLR, MPV, and MPV/PLT decreased. We effectively established RIs for the indicators. They will help with predicting disease progression in various clinical practices. Gender, age, and BMI were suggested to be taken into consideration when these parameters were applied in clinical.

First development of the Malaysian River Integrity Index (MyRII) based on biological, chemical and physical multi-metrics.

Anthropogenic pressures are causing substantial degradation to the freshwater ecosystems globally and Malaysia has not escaped such a bleak scenario. Prompted by the predicament, this study's objective was to pioneer a river assessment system that can be readily adopted to monitor, manage and drive improvement in a wholesome manner. Three sets of a priori metrics were selected to form the Ichthyofaunal Quality Index (IQI: biological), Water Quality Index (WQI: chemical) and River Physical Quality Index (RPQI: physical). These indices were further integrated on equal weighting to construct a novel Malaysian River Integrity Index (MyRII). To test its robustness, the MyRII protocol was field tested in four eco-hydrological zones located in the Kampar River water basin for 18 months to reveal its strengths, weaknesses, and establish the "excellent", "good", "average", "poor" and "impaired" thresholds based on the "best performer" reference site in an empirical manner. The resultant MyRII showed a clear trend that corresponded with different levels of river impairment. Test site zone A which was a reference site with minimal disturbance achieved the highest MyRII (88.95 ± 4.29), followed by partially disturbed zone B (61.95 ± 5.90) and heavily disturbed zone C (50.00 ± 4.29). However, the MyRII in zone D (59.9 ± 6.39), which was a heavily disturbed wetland that was disjointed from the river, did not conform to such trend. Also unveiled and recognized, however, are some unexpected nuances, limitations and challenges that emerged from this study. These are critically discussed as precautions when interpreting and implementing the MyRII protocol. This study adds to the mounting body of evidence that water resource stakeholders and policymakers must look at the big picture and adopt the "balanced ecosystem" mind-set when assessing, restoring and managing the rivers as a freshwater resource.

Baltic cod endohelminths reflect recent ecological changes.

We suggest helminthological investigations of cod as a supplement to traditional biological and hydrographical methods for elucidation of ecological changes in the Baltic Sea. It is under discussion if oxygen deficit or seal abundance should explain the present critical situation of Baltic cod. A comparative investigation of endoparasitic helminths in Baltic cod (Gadus morhua), captured in the same marine habitat with an interval of 35 years (1983/2018) recorded 11 species of helminths comprising trematodes (Hemiurus luehei, Podocotyle atomon, Lepidapedon elongatum), nematodes (Contracaecum osculatum, Hysterothylacium aduncum, Capillaria gracilis, Cucullanus cirratus), cestodes (Bothriocephalus sp.) and acanthocephalans (Echinorhynchus gadi, Pomphorhynchus laevis, Corynosoma semerme). Significant prevalence and intensity increases were recorded for third-stage larvae of the nematode C. osculatum (liver location) and larvae of C. semerme (encapsulated in viscera). Both parasite species use grey seal as their final host, indicating the recent expansion of the Baltic seal population. A lower E. gadi intensity and an increased prevalence of L. elongatum of small cod (31-40 cm body length) suggest a lowered intake of amphipods (intermediate host) and elevated ingestion of polychaetes, respectively, but no significant changes were seen for other helminths.

Combined toxicity of imidacloprid and cadmium on histopathology and acetylcholinesterase activity in aquatic oligochaetes (Tubifex tubifex Müller, 1774).

Imidacloprid is one of the neonicotinoid insecticides that has been applied in many farmlands and was detected in many water resources worldwide. However, not only this insecticide but also cadmium was found in the agricultural wastewater in close proximity to industrial areas. This research aims to investigate the acute toxicity of imidacloprid and cadmium on the biochemical changes, pathological changes and accumulation of cadmium in Tubifex tubifex after 24- and 48-h exposure. The results show that combined toxicity of two chemicals was synergistic. In combined toxicity test, cadmium accumulation and acetylcholinesterase activity in worm tissue were significantly increased when compared with the single test. The severity of histopathology shows a dose-dependent relationship. Epidermal and gut cell degeneration, hyperplasia of epidermal and gut cells, irregular surface of the epidermis, overexpression of chloragosome and nerve degeneration were observed. Overall, this research provides useful bio-markers to assess the toxicity of imidacloprid and cadmium on the aquatic environment.

Neurogenesis and antidepressant action.

A theoretical framework is proposed to gain insight into the pathogenesis of major depressive disorder (MDD). Despite being a relatively weak argument, the neurogenesis theory is suggested to compensate for the limitations of the monoamine theory. In the adult hippocampus, neurogenesis is functionally related to regulation of the hypothalamic-pituitary-adrenal (HPA) axis, inflammatory processes, cognitive functions and other aspects that contribute to etiological factors that lead to MDD and promote recovery from MDD. Despite a lack of investigation into neurogenesis and antidepressant action, it is proposed that chronic administration of antidepressant(s) can induce the recruitment and integration of newborn neurons into the dentate gyrus and, ultimately, lead to the remission of MDD. The extant body of literature indicates that the suppression of neurogenesis per se may be associated with an impaired response to antidepressant treatment rather than with the induction of depressive-like behaviors. Moreover, recent studies have shown that increasing the survival rate and incorporation of new neurons can alleviate depressive-like behaviors and promote stress resilience. According to the neurogenic reserve hypothesis, hippocampal neurogenesis supports specific cortical functions, including executive functions, pattern separation and contextual information processing, control over the HPA axis and behavioral coping mechanisms in response to stressful situations. Therefore, hippocampal neurogenesis may be a promising biological indicator of stress resilience and antidepressant response in patients with MDD.

Evaluating how variants of floristic quality assessment indicate wetland condition.

Biological indicators are useful tools for the assessment of ecosystem condition. Multi-metric and multi-taxa indicators may respond to a broader range of disturbances than simpler indicators, but their complexity can make them difficult to interpret, which is critical to indicator utility for ecosystem management. Floristic Quality Assessment (FQA) is an example of a biological assessment approach that has been widely tested for indicating freshwater wetland condition, but less attention has been given to clarifying the factors controlling its response. FQA quantifies the aggregate of vascular plant species tolerance to habitat degradation (conservatism), and model variants have incorporated species richness, abundance, and indigenity (native or non-native). To assess bias, we tested FQA variants in open-canopy freshwater wetlands against three independent reference measures, using practical vegetation sampling methods. FQA variants incorporating species richness did not correlate with our reference measures and were influenced by wetland size and hydrogeomorphic class. In contrast, FQA variants lacking measures of species richness responded linearly to reference measures quantifying individual and aggregate stresses, suggesting a broad response to cumulative degradation. FQA variants incorporating non-native species, and a variant additionally incorporating relative species abundance, improved performance over using only native species. We relate our empirical findings to ecological theory to clarify the functional properties and implications of the FQA variants. Our analysis indicates that (1) aggregate conservatism reliably declines with increased disturbance; (2) species richness has varying relationships with disturbance and increases with site area, confounding FQA response; and (3) non-native species signal human disturbance. We propose that incorporating species abundance can improve FQA site-level relevance with little extra sampling effort. Using our practical sampling methods, an FQA variant ignoring species richness and incorporating non-native species and relative species abundance can be logistically efficient, easily understood, and effective for wetland assessment.

Bacteria as Emerging Indicators of Soil Condition.

Bacterial communities are important for the health and productivity of soil ecosystems and have great potential as novel indicators of environmental perturbations. To assess how they are affected by anthropogenic activity and to determine their ability to provide alternative metrics of environmental health, we sought to define which soil variables bacteria respond to across multiple soil types and land uses. We determined, through 16S rRNA gene amplicon sequencing, the composition of bacterial communities in soil samples from 110 natural or human-impacted sites, located up to 300 km apart. Overall, soil bacterial communities varied more in response to changing soil environments than in response to changes in climate or increasing geographic distance. We identified strong correlations between the relative abundances of members of Pirellulaceae and soil pH, members of Gaiellaceae and carbon-to-nitrogen ratios, members of Bradyrhizobium and the levels of Olsen P (a measure of plant available phosphorus), and members of Chitinophagaceae and aluminum concentrations. These relationships between specific soil attributes and individual soil taxa not only highlight ecological characteristics of these organisms but also demonstrate the ability of key bacterial taxonomic groups to reflect the impact of specific anthropogenic activities, even in comparisons of samples across large geographic areas and diverse soil types. Overall, we provide strong evidence that there is scope to use relative taxon abundances as biological indicators of soil condition. IMPORTANCE: The impact of land use change and management on soil microbial community composition remains poorly understood. Therefore, we explored the relationship between a wide range of soil factors and soil bacterial community composition. We included variables related to anthropogenic activity and collected samples across a large spatial scale to interrogate the complex relationships between various bacterial community attributes and soil condition. We provide evidence of strong relationships between individual taxa and specific soil attributes even across large spatial scales and soil and land use types. Collectively, we were able to demonstrate the largely untapped potential of microorganisms to indicate the condition of soil and thereby influence the way that we monitor the effects of anthropogenic activity on soil ecosystems into the future.

Spatial and temporal ecological risk assessment of unionized ammonia nitrogen in Tai Lake, China (2004-2015).

Ammonia toxicity varies largely due to its pH- and temperature-dependent speciation (unionized ammonia nitrogen, NH3-N). The seasonal and long-term trend of ammonia risk in ecologically significant sections of Tai Lake, China was unknown. In this study, a two-level (deterministic and quantitative) method was developed to assess the special ecological risks posed by NH3-N at 37 sites during two seasons (February and September) of 2014 in Tai Lake. The long-term temporal (2004-2015) risk posed by NH3-N was also assessed by comparing annual quantitative risk values (probability of exceeding acute or chronic threshold values) in three key sections of Tai Lake. The results indicated the species living in the Tai Lake were at a 0.04% and 32.45% chance of risk due to acute exposure, and a 1.97% and 92.05% chance of risk due to chronic exposure in February and September of 2014, respectively. Alarmingly, the chronic ecological risks of NH3-N in the Lanshanzui section of the Tai Lake remained >30% from 2004 to 2011. The chronic risk of NH3-N in all three key sections of Tai Lake started to decrease in 2011. This was likely the consequence of the control practice of eutrophication implemented in the Tai Lake. A significant decline in diversity of the benthic invertebrate community of the Tai Lake could be associated with continuous exposure to ammonia over decades given different sensitivity of taxa to ammonia. The results laid a scientific foundation for risk assessment and management of ammonia in Tai Lake, China, and the developed two-level risk assessment approach can also be applied to other similar aquatic regions.

Response of macroinvertebrate communities to seasonal hydrologic changes in three sub-tropical Australian streams.

In the Australian sub-tropics, seasonal changes in hydrology can influence abiotic conditions, and consequently, the biota. Several methods of macroinvertebrate analyses, including the use of taxonomic groupings, are used to ascertain information regarding stream biodiversity and health. The use of biological traits to group and analyse macroinvertebrate communities, however, may provide a better picture of stream health, particularly in ephemeral streams. To address whether this is the case, three ephemeral systems in the lower Fitzroy catchment, Central Queensland, Australia, were studied over an 18-month period. A total of 69 macroinvertebrate families from 14 orders were collected in 128 samples. Taxonomic analysis indicated there was a range of habitat preferences within groups characterized by a large proportion of tolerant and generalist taxa. The macroinvertebrate communities were categorised into biological trait groups, with a number of predator families found during all flow regimes. A general pattern of Gatherer > Predator > Grazer > Shredder > Filterer was observed. This study provides a clear pattern of the biological traits present during variable flow and could be used as a framework for future stream health modelling. A trait-specific management tool for assessing freshwaters has not yet been adopted in global management protocols and would require both a more definitive understanding of patterns during different flow periods and an internationally recognised set of trait nomenclature.

A temporal and spatial monitoring of organotin pollution in a harborside region of Brazil by imposex and ecological quality ratio using Leucozonia nassa.

This study represents the first use of Leucozonia nassa (Mollusca-Gastropoda) in a program of long-term monitoring. Specimens of L. nassa were collected between 2006 and 2014 and analyzed for the occurrence of imposex in two areas in Southeastern Brazil, one control area and another characterized by the presence of many ports and marinas. Imposex was evaluated in nine sites based on the percentage of females exhibiting imposex (I%), relative penis length index and vas deferens sequence index, classical indices to evaluate tributyltin (TBT) impacts. Moreover, this study uses for the first time in a tropical environment the ecological quality ratio (EQR), an approach to verify the imposex levels as an indicator of the impact by organotin compounds according to the EU Water Framework Directive. The results confirm the occurrence of high levels of imposex in L. nassa with all the indices evaluated. Furthermore, the results also indicate that, despite the international ban, antifouling paints based on TBT are still possibly used in Brazil. In addition, this study shows that L. nassa has the characteristics that make it a suitable bioindicator to monitor TBT pollution, and that the use of the EQR may create important data regarding this problem.

Evaluating different concentrations of hydrogen peroxide in an automated room disinfection system.

UNLABELLED: A comparative study was made on the efficacy of 5, 10 and 35% weight by weight (w/w) hydrogen peroxide solutions when applied using an automated room disinfection system. Six-log biological indicators of methicillin-resistant Staphylococcus aureus (MRSA) and Geobacillus stearothermophilus were produced on stainless steel coupons and placed within a large, sealed, environmentally controlled enclosure. Five percent hydrogen peroxide was distributed throughout the enclosure using a Bioquell hydrogen peroxide vapour generator (BQ-50) for 40 min and left to reside for a further 200 min. Biological indicators were removed at 10-min intervals throughout the first 120 min of the process. The experiment was repeated for 10 and 35% hydrogen peroxide solutions. Five percent and 10% hydrogen peroxide solutions failed to achieve any reduction of MRSA, but achieved full kill of G. stearothermophilus spores at 70 and 40 min respectively. Thirty-five percent hydrogen peroxide achieved a 6-log reduction of MRSA after 30 min and full kill of G. stearothermophilus at 20 min. The concentration of 5% hydrogen peroxide within the enclosure after the 200-min dwell was measured at 9·0 ppm. This level exceeds the 15-min Short Term Exposure Limit (STEL) for hydrogen peroxide of 2·0 ppm. Users of automated hydrogen peroxide disinfection systems should review system efficacy and room re-entry protocols in light of these results. SIGNIFICANCE AND IMPACT OF THE STUDY: This research allows hospital infection control teams to consider the impact and risks of using low concentrations of hydrogen peroxide for disinfection within their facilities, and to question automated room disinfection system providers on the efficacy claims they make. The evidence that low concentration hydrogen peroxide solutions do not rapidly, autonomously break down, is in contradiction to the claims made by some hydrogen peroxide equipment providers and raises serious health and safety concerns. Facilities using hydrogen peroxide systems that claim autonomous break down of hydrogen peroxide should introduce monitoring procedures to ensure rooms are safe for re-entry and patient occupation.

Bacillus atrophaeus: main characteristics and biotechnological applications - a review.

The genus Bacillus includes a great diversity of industrially important strains, including Bacillus atrophaeus (formerly Bacillus subtilis var. niger). This spore-forming bacterium has been established as industrial bacteria in the production of biological indicators for sterilization, in studies of biodefense and astrobiology methods as well as disinfection agents, in treatment evaluation and as potential adjuvants or vehicles for vaccines, among other applications. This review covers an overview of the fundamental aspects of the B. atrophaeus that have been studied to date. Although the emphasis is placed on recent findings, basic information's such as multicellularity and growth characteristics, spore structure and lifecycle are described. The wide biotechnological application of B. atrophaeus spores, including vegetative cells, is briefly demonstrated, highlighting their use as a biological indicator of sterilization or disinfection.

Behavioral correction to prevent overhydration and increase survival by larvae of the net-spinning caddisflies in relation to water flow.

We report behavioral regulation of body water content in caddisfly larvae, Hydropsyche morosa and Cheumatopsyche pettiti, by selecting microhabitats with different water flow rates. The purpose of our study was to examine features necessary for survival in the same apparent habitat, because the two species co-exist in riffle areas of freshwater streams. Both species are highly sensitive to water loss as a result of high water loss rates and depend on immersion in fresh water (hypo-osmotic) to maintain water stores. In contrast to C. pettiti, H. morosa is larger, retains water more effectively, and features reduced water loss rates with suppressed activation energies. When H. morosa was confined to areas of low or no water flow, overhydration led to rapid mortality, whereas the same conditions favored water balance maintenance and survival in C. pettiti. In attraction bioassays, H. morosa moved and remained within areas of high water flow and C. pettiti preferred areas with low water flow. Because water flow rates are unlikely to directly impact water gain, the mechanism responsible for increased survival and water balance maintenance is likely related to the impact of water flow on oxygen availability, differences in feeding ecology, or other underlying factors.