Regulatory Monitoring Research Articles

Simulated Impact of Vitamin A Fortified Sugar on Dietary Adequacy and Association of Usual Sugar Intake With Plasma and Breast Milk Retinol Among Lactating Women in Rural Zambia

ObjectivesZambia introduced mandatory sugar fortification with vitamin A (VA) in 1998; however, regulatory monitoring and evaluation have been limited. We studied the contribution of VA-fortified sugar intake to dietary adequacy, and examined associations between usual sugar and VA intakes with plasma and breast milk retinol concentrations in lactating women in rural Zambia. MethodsWe conducted three 24-h dietary recalls among each of 255 lactating women enrolled in a randomized trial, at the time of baseline venous blood and breast milk collection. We measured retinol in biospecimens using high-performance liquid chromatography. We simulated VA intake under various sugar fortification scenarios: 3.1 and 8.8 mg/kg (measured median fortification levels of VA in sugar from previous studies), 10 mg/kg (minimum legal requirement) and 15 mg/kg (minimum legal requirement at factory level). Usual intake distributions, prevalence of inadequate VA intake (< Estimated Average Requirement of 900 μg RAE/d) and prevalence of retinol intake above the tolerable upper intake level (UL, >3000 μg/d) for each scenario were estimated using the National Cancer Institute (NCI) method. We applied the NCI’s “bivariate model” as a regression calibration tool to examine associations of usual intake of sugar and dietary VA with plasma and breast milk retinol concentrations. ResultsIn the absence of sugar fortification, the prevalence of VA inadequacy was predicted to be 83% (SE: 6). Fortification of sugar with VA at 3.1 mg/kg, 8.8 mg/kg, 10 mg/kg and 15 mg/kg would reduce the prevalence of VA inadequacy by 7 (SE:6), 24 (SE:14), 30 (SE:15) and 47 (SE:18) percentage points, respectively, without increasing the risk of retinol intake above the UL. Usual sugar intake and usual VA intake were not associated with plasma retinol or breastmilk retinol concentrations. ConclusionsThe sugar fortification program has the potential to reduce dietary VA inadequacy, but the impact is likely to be limited if actual fortification levels are lower than mandated levels. Even if target fortification levels are achieved (10 mg/kg), sugar fortification alone is unlikely to eliminate dietary VA inadequacy among lactating women in rural Zambia. Funding SourcesHarvestPlus and the Sight and Life Global Nutrition Research Institute at Johns Hopkins University.

Persistence of Primary and Secondary Pollutants in Delhi: Concentrations and Composition from 2017 through the COVID Pandemic

We assess impacts of the 2020 COVID-19 lockdown on ambient air quality in Delhi, building on over three years of real-time measurements of black carbon (BC) and nonrefractory submicrometer aerosol (NR-PM1) composition from the Delhi Aerosol Supersite and public data from the regulatory monitoring network. We performed source apportionment of organic aerosol (OA) and robust statistical analyses to differentiate lockdown-related impacts from baseline seasonal and interannual variability. The primary pollutants NOx, CO, and BC were most reduced, primarily due to lower transportation emissions. Local and regional emissions such as agricultural burning decreased during the lockdown. PM2.5 declined but remained well above WHO guidelines. Despite the lockdown, NR-PM1 changed only moderately compared to prior years. Differences in the trends of hydrocarbon-like OA and BC suggest that some sources of primary aerosol may have increased. Despite notable reductions in some primary pollutants, the lockdown restrictions led to rather small perturbations in the primary fraction of NR-PM1, with secondary aerosol continuing to dominate. Overall, our results demonstrate the impact of secondary and primary pollution on Delhi's air quality and show that large changes in emissions within Delhi alone are insufficient to bring about needed improvements in air quality. © 2021 American Chemical Society.

Spatial and temporal variability of ozone along the Colorado Front Range occurring over 2 days with contrasting wind flow

Transport of pollution into pristine wilderness areas is of concern for both federal and state agencies. Assessing such transport in complex terrain is a challenge when relying solely on data from standard federal or state air quality monitoring networks because of the sparsity of network monitors beyond urban areas. During the Front Range air quality study, conducted in the summer of 2008 in the vicinity of Denver, CO, research-grade surface air quality data, vertical wind profiles and mixing heights obtained by radar wind profilers, and ozone profile data obtained by an airborne ozone differential absorption lidar augmented the local regulatory monitoring networks. Measurements from this study were taken on 2 successive days at the end of July 2008. On the first day, the prevailing winds were downslope westerly, advecting pollution to the east of the Front Range metropolitan areas. On this day, chemistry measurements at the mountain and foothills surface stations showed seasonal background ozone levels of approximately 55–68 ppbv (nmol mol–1 by volume). The next day, upslope winds prevailed, advecting pollution from the Plains into the Rocky Mountains and across the Continental Divide. Mountain stations measured ozone values greater than 90 ppbv, comparable to, or greater than, nearby urban measurements. The measurements show the progression of the ozone-enriched air into the mountains and tie the westward intrusion into high-elevation mountain sites to the growth of the afternoon boundary layer. Thus, under deep upslope flow conditions, ozone-enriched air can be advected into wilderness areas of the Rocky Mountains. Our findings highlight a process that is likely to be an important ozone transport mechanism in mountainous terrain adjacent to ozone source areas when the right circumstances come together, namely a deep layer of light winds toward a mountain barrier coincident with a deep regional boundary layer.

Passive sampling with suspect screening of polar pesticides and multivariate analysis in river catchments: Informing environmental risk assessments and designing future monitoring programmes

Pollution of surface water by polar pesticides is a major environmental risk, particularly in river catchments where potable water supplies are abstracted. In these cases, there is a need to understand pesticide sources, occurrence and fate. Hence, we developed a novel strategy to improve water quality management at the catchment scale using passive sampling coupled to suspect screening and multivariate analysis. Chemcatcher® passive sampling devices were deployed (14 days) over a 12 month period at eight sites (including a water supply works abstraction site) in the Western Rother, a river catchment in South East England. Sample extracts (n = 197) were analysed using high-resolution liquid chromatography-quadrupole-time-of-flight mass spectrometry and compounds identified against a commercially available database. A total of 128 pesticides from different classes were found. Statistical analysis of the qualitative screening data was used to identify clusters of pesticides with similar spatiotemporal pollution patterns. This enabled pesticide sources and fate to be identified. At the water supply works abstraction site, spot sampling and passive sampling were found to be complementary, however, the passive sampling method in conjunction with suspect screening detected 50 pesticides missed by spot sampling combined with targeted analysis. Geospatial data describing pesticide application rates was found to be poorly correlated to their detection frequency using the Chemcatcher®. Our analysis prioritised 61 pesticides for inclusion in a future water quality risk assessment at the abstraction site. It was also possible to design a seasonal monitoring programme to effectively characterise the spatiotemporal pesticide profiles within the catchment. A work flow of how to incorporate passive sampling coupled to suspect screening into existing regulatory monitoring is proposed. Our novel approach will enable water quality managers to target the mitigation (non-engineered actions) of pesticide pollution within the catchment and hence, to better inform drinking water treatment processes and save on operational costs.

On the distribution of low-cost PM2.5 sensors in the US: demographic and air quality associations.

Low-cost sensors have the potential to democratize air pollution information and supplement regulatory networks. However, differentials in access to these sensors could exacerbate existing inequalitiesin the ability of different communitiesto respond to the threat of air pollution. Our goal was to analyze patterns of deployments of a commonly used low-cost sensor, as a function of demographics and pollutant concentrations. We used Wilcoxon rank sum tests to assess differences between socioeconomic characteristics and PM2.5 concentrations of locations with low-cost sensors and those with regulatory monitors. We used Kolomogorov-Smirnov tests to examine how representative census tracts with sensors were of the United States. We analyzed predictors of the presence, and number of, sensors in a tract using regressions. Census tracts with low-cost sensors were higher income more White and more educated than the US as a whole and than tracts with regulatory monitors. For all states except for California they are in locations with lower annual-average PM2.5 concentrations than regulatory monitors. The existing presence of a regulatory monitor, the percentage of people living above the poverty line and PM2.5 concentrations were associated with the presence of low-cost sensors in a tract. Strategies to improve access to low-cost sensors in less-privileged communities are needed to democratize air pollution data.

Application and Evaluation of a Low-cost PM Sensor and Data Fusion with CMAQ Simulations to Quantify the Impacts of Prescribed Burning on Air Quality in Southwestern Georgia, USA

ABSTRACT Prescribed burning (PB) is a prominent source of PM2.5 in the southeastern US and exposure to PB smoke is a health risk. As demand for burning increases and stricter controls are implemented for other anthropogenic sources, PB emissions tend to be responsible for an increasing fraction of PM2.5 concentrations. Here, to quantify the effect of PB on air quality, low-cost sensors are used to measure PM2.5 concentrations in Southwestern Georgia. The feasibility of using low-cost sensors as a supplemental measurement tool is evaluated by comparing them with reference instruments. A chemical transport model, CMAQ, is also used to simulate the contribution of PB to PM2.5 concentrations. Simulated PM2.5 concentrations are compared to observations from both low-cost sensors and reference monitors. Finally, a data fusion method is applied to generate hourly spatiotemporal exposure fields by fusing PM2.5 concentrations from the CMAQ model and all observations. The results show that the severe impact of PB on local air quality and public health may be missed due to the dearth of regulatory monitoring sites. In Southwestern Georgia PM2.5 concentrations are highly non-homogeneous and the spatial variation is not captured even with a 4-km horizontal resolution in model simulations. Low-cost PM sensors can improve the detection of PB impacts and provide useful spatial and temporal information for integration with air quality models. R2 of regression with observations increases from an average of 0.09 to 0.40 when data fusion is applied to model simulation withholding the observations at the evaluation site. Adding observations from low-cost sensors reduces the underestimation of nighttime PM2.5 concentrations and reproduces the peaks that are missed by the simulations. In the future, observations from a dense network of low-cost sensors could be fused with the model simulated PM2.5 fields to provide better estimates of hourly exposures to smoke from PB. Prescribed burning emissions are a major cause of elevated PM2.5 concentrations, posing a risk to human health. However, their impact cannot be quantified properly due to a dearth of regulatory monitoring sites in certain regions of the United States such as Southwestern Georgia. Low-cost PM sensors can be used as a supplemental measurement tool and provide useful spatial and temporal information for integration with air quality model simulations. In the future, data from a dense network of low-cost sensors could be fused with model simulated PM2.5 fields to provide improved estimates of hourly exposures to smoke from prescribed burning. Impliation statement

Occurrence of male-specific and somatic coliphages and relationship with rainfall in privately-owned wells from peri‑urban and rural households

Privately-owned drinking water wells serving fewer than 25 people (private wells) are prevalent and understudied across most of the US. Private wells primarily serve rural households located outside of municipal drinking water and sewerage service coverage areas. These wells are not regulated by United States Environmental Protection Agency (EPA) under the Safe Drinking Water Act, are not regularly monitored by any public agency or utility, and generally do not undergo disinfection treatment. Coliphages are a group of viruses that infect coliform bacteria and are useful viral surrogates for fecal contamination in water systems in much the same way that fecal indicator bacteria (FIB), such as E. coli and to a lesser extent total coliforms, are used to quantify fecal contamination. Coliphages are approved by the EPA for regulatory monitoring in groundwater wells in the USA, but are not routinely used for this purpose. The present study characterizes the occurrence of male-specific and somatic coliphages, along with FIB, in private wells (n = 122) across two different counties in North Carolina. While occurrences of E. coli were rare and frequency of total coliform was generally low (~20%), male-specific and somatic coliphages were detectable in 66% and 54% of samples, respectively. Concentrations of male-specific coliphages were higher than somatics at each county and on a monthly basis. Rainfall appears to be partly influencing higher coliphage concentrations in December, January and February. This research underscores the need for increased surveillance in private wells and consideration of using coliphages in order to better characterize occurrence of fecal contamination at the time of sampling, especially during rainier months.

Childhood traffic-related air pollution and adverse changes in subclinical atherosclerosis measures from childhood to adulthood

BackgroundChronic exposure to air pollutants is associated with increased risk of cardiovascular disease (CVD) among adults. However, little is known about how air pollution may affect the development of subclinical atherosclerosis in younger populations. Carotid artery intima-media thickness (CIMT) is a measure of subclinical atherosclerosis that provides insight into early CVD pathogenesis.MethodsIn a pilot study of 70 participants from the Southern California Children’s Health Study, we investigated CIMT progression from childhood to adulthood. Using carotid artery ultrasound images obtained at age 10 and follow-up images at age 21–22, we examined associations between childhood ambient and traffic-related air pollutants with changes in CIMT over time and attained adult CIMT using linear mixed-effects models adjusted for potential confounders.Average residential childhood exposures (i.e., birth to time of measurement at 10–11 years) were assigned for regional, ambient pollutants (ozone, nitrogen dioxide, particulate matter, interpolated from regulatory air monitoring data) and traffic-related nitrogen oxides (NOx) by road class (modeled using the CALINE4 line source dispersion model). Traffic density was calculated within a 300-m residential buffer.ResultsFor each 1 standard deviation (SD) increase in childhood traffic-related total NOx exposure, we observed greater yearly rate of change in CIMT from childhood to adulthood (β: 2.17 μm/yr, 95% CI: 0.78–3.56). Increases in annual rate of CIMT change from childhood to adulthood also were observed with freeway NOx exposure (β: 2.24 μm/yr, 95% CI: 0.84–3.63) and traffic density (β: 2.11 μm/yr, 95% CI: 0.79–3.43). Traffic exposures were also related to increases in attained CIMT in early adulthood. No associations of CIMT change or attained level were observed with ambient pollutants.ConclusionsOverall, we observed adverse changes in CIMT over time in relation to childhood traffic-related NOx exposure and traffic density in our study population. While these results must be cautiously interpreted given the limited sample size, the observed associations of traffic measures with CIMT suggest a need for future studies to more fully explore this relationship.

The fractionation of phosphorus in UK chalk stream surface waters and its relevance to the regulation and management of water quality

The regulatory management of river water quality requires measurements of phosphorus that are operationally viable and meaningful in terms of insight into its effects. This need is a particular concern in globally rare and ecologically sensitive chalk streams. P data pertaining to rivers are commonly limited to soluble reactive P; other fractions of P may be of concern but are not routinely monitored. This study seeks to establish the nature and extent of non-regulated forms of P in UK chalk streams. Whilst soluble reactive P in two southern English chalk streams was found to comprise the majority of reactive P in surface waters in the majority of samples, 15–20% of the total reactive P was within other size fractions greater than 0.22 μm. The contribution of reactive P to the total P was highly variable. We conclude that, with some adjustments, the established method of regulatory monitoring of P in UK rivers is viable and valuable. In cases where the levels of reactive P are not consistent with ecological status and/or expected outcomes of programmes of measures, we recommend that targeted analysis of non-regulated forms of P is undertaken as a means to guide and focus management interventions.

Retrospective non-target analysis to support regulatory water monitoring: from masses of interest to recommendations via in silico workflows

BackgroundApplying non-target analysis (NTA) in regulatory environmental monitoring remains challenging—instead of having exploratory questions, regulators usually already have specific questions related to environmental protection aims. Additionally, data analysis can seem overwhelming because of the large data volumes and many steps required. This work aimed to establish an open in silico workflow to identify environmental chemical unknowns via retrospective NTA within the scope of a pre-existing Swiss environmental monitoring campaign focusing on industrial chemicals. The research question addressed immediate regulatory priorities: identify pollutants with industrial point sources occurring at the highest intensities over two time points. Samples from 22 wastewater treatment plants obtained in 2018 and measured using liquid chromatography–high resolution mass spectrometry were retrospectively analysed by (i) performing peak-picking to identify masses of interest; (ii) prescreening and quality-controlling spectra, and (iii) tentatively identifying priority “known unknown” pollutants by leveraging environmentally relevant chemical information provided by Swiss, Swedish, EU-wide, and American regulators. This regulator-supplied information was incorporated into MetFrag, an in silico identification tool replete with “post-relaunch” features used here. This study’s unique regulatory context posed challenges in data quality and volume that were directly addressed with the prescreening, quality control, and identification workflow developed.ResultsOne confirmed and 21 tentative identifications were achieved, suggesting the presence of compounds as diverse as manufacturing reagents, adhesives, pesticides, and pharmaceuticals in the samples. More importantly, an in-depth interpretation of the results in the context of environmental regulation and actionable next steps are discussed. The prescreening and quality control workflow is openly accessible within the R package Shinyscreen, and adaptable to any (retrospective) analysis requiring automated quality control of mass spectra and non-target identification, with potential applications in environmental and metabolomics analyses.ConclusionsNTA in regulatory monitoring is critical for environmental protection, but bottlenecks in data analysis and results interpretation remain. The prescreening and quality control workflow, and interpretation work performed here are crucial steps towards scaling up NTA for environmental monitoring.

Current Trends and Challenges for Rapid SMART Diagnostics at Point-of-Site Testing for Marine Toxins.

In the past twenty years marine biotoxin analysis in routine regulatory monitoring has advanced significantly in Europe (EU) and other regions from the use of the mouse bioassay (MBA) towards the high-end analytical techniques such as high-performance liquid chromatography (HPLC) with tandem mass spectrometry (MS). Previously, acceptance of these advanced methods, in progressing away from the MBA, was hindered by a lack of commercial certified analytical standards for method development and validation. This has now been addressed whereby the availability of a wide range of analytical standards from several companies in the EU, North America and Asia has enhanced the development and validation of methods to the required regulatory standards. However, the cost of the high-end analytical equipment, lengthy procedures and the need for qualified personnel to perform analysis can still be a challenge for routine monitoring laboratories. In developing regions, aquaculture production is increasing and alternative inexpensive Sensitive, Measurable, Accurate and Real-Time (SMART) rapid point-of-site testing (POST) methods suitable for novice end users that can be validated and internationally accepted remain an objective for both regulators and the industry. The range of commercial testing kits on the market for marine toxin analysis remains limited and even more so those meeting the requirements for use in regulatory control. Individual assays include enzyme-linked immunosorbent assays (ELISA) and lateral flow membrane-based immunoassays (LFIA) for EU-regulated toxins, such as okadaic acid (OA) and dinophysistoxins (DTXs), saxitoxin (STX) and its analogues and domoic acid (DA) in the form of three separate tests offering varying costs and benefits for the industry. It can be observed from the literature that not only are developments and improvements ongoing for these assays, but there are also novel assays being developed using upcoming state-of-the-art biosensor technology. This review focuses on both currently available methods and recent advances in innovative methods for marine biotoxin testing and the end-user practicalities that need to be observed. Furthermore, it highlights trends that are influencing assay developments such as multiplexing capabilities and rapid POST, indicating potential detection methods that will shape the future market.

COVID-19 and the Emerging Regulatory Guidance for Ongoing Clinical Trials in the European Union.

The coronavirus disease 2019 (COVID‐19) pandemic and the accompanying control measures have significantly affected clinical trial (CT) conduct, and sponsors have needed to make rapid changes to their CT operations. As a result, regulatory guidance was pivotal during the initial phases of the pandemic. This study aimed to evaluate the regulatory readiness and guidance related to COVID‐19 in the European Union (EU). The European Medicines Agency (EMA) and national competent authorities’ (NCAs') websites were searched in September and October 2020 for guidances on the management of CTs during the pandemic published from January 2020 onward. “Regulatory readiness” was defined as the number of days from the first European COVID‐19 case (January 24, 2020) to the first published guidance by the respective NCA. “Regulatory guidance” was evaluated by coding the guidances for the following predefined operational trial activities important for ongoing CTs: obtaining informed consent, participant information, clinic visits, home health visits, telemedicine visits, self‐monitoring, investigational medicinal product (IMP) supply, IMP adherence monitoring, CT monitoring, documentation management, regulatory management, and safety management. Twenty‐four of the 27 EU NCAs published country‐specific guidance. The time from the first European COVID‐19 case to the first published EMA guidance was 56 days and ranged from 47 to 66 days for the first national guidances. Guidance was provided most frequently for regulatory management (24/24), safety management (23/24), documentation management (22/24), and CT monitoring (22/24). The regulatory guidance provided during the pandemic, ensuring participant safety and data integrity, may now be the starting point to innovate future CT conduct.

Assessment of Professional Negligence in the Nigerian Construction Industry

Professional negligence involves neglecting professional duty of care as to render the professional responsible for the act, error or omission of neglect, liable in law to a client or some third party who sustains loss by reason of that neglect. This study investigates the effects of professional negligence in construction industry, with a view to proffering means of minimizing it. The objective is to identify the causes of professional negligence in the construction industry; to assess the effect of professional negligence in the construction industry and to investigate how professional negligence in construction industry can be minimized. A total number of 100 questionnaire were administered to the professionals in Oyo State which is the study area. The data were analyzed using frequency, Descriptive and Ranking to check the level of the effects of professional negligence in construction industry. In conclusion the major causes of professional negligence is inadequately flow of communication, inadequate standard of the company and professional negligence has a far reaching effect; some of the effects are exposure to high risk, low quality, client dissatisfaction, delay in project delivery, financial loss and reputation of the industry. It was recommended that adequate flow of information should be put in place and also there should be mandatory condition that must be obeyed at all times, violation of a rule should be ground for disciplinary action by the professionals and the site should not be handled by inexperience contractor. The required solution to professional negligence in the construction industry is Effective professional regulatory monitoring, Monitoring by Regulatory Authority, Site Meeting and Compulsory continuous professional development.

Food Fortification: The Advantages, Disadvantages and Lessons from Sight and Life Programs.

Deficiencies in one or more micronutrients such as iron, zinc, and vitamin A are widespread in low- and middle-income countries and compromise the physical and cognitive capacity of millions of people. Food fortification is a cost-effective strategy with demonstrated health, economic and social benefits. Despite ongoing debates globally and in some countries regarding the performance and safety of food fortification, the practice offers significant benefits across each of the main vehicles for food fortification (large-scale food fortification, biofortification and point-of-use or home fortification) ranging from reducing the prevalence of nutritional deficiencies and economic benefits to societies and economies. Using Sight and Life’s global and national experiences in implementing food fortification efforts, we demonstrate how different programs in LMICs have successfully addressed challenges with food fortification and in doing so, find that these efforts are most successful when partnerships are formed that include the public and private sector as well as other parties that can provide support in key areas such as advocacy, management, capacity building, implementation and regulatory monitoring.

Monitoring Air Pollution Variability during Disasters

National environmental regulations lack short-term standards for variability in fine particulate matter (PM2.5); they depend solely on concentration-based standards. Twenty-five years of research has linked short-term PM2.5, that is, increases of at least 10 μg/m3 that can occur in-between regulatory readings, to increased mortality. Even as new technologies have emerged that could readily monitor short-term PM2.5, such as real-time monitoring and mobile monitoring, their primary application has been for research, not for air quality management. The Gulf oil spill offers a strategic setting in which regulatory monitoring, computer modeling, and stationary monitoring could be directly compared to mobile monitoring. Mobile monitoring was found to best capture the variability of PM2.5 during the disaster. The research also found that each short-term increase (≥10 μg/m3) in fine particulate matter was associated with a statistically significant increase of 0.105 deaths (p &lt; 0.001) in people aged 65 and over, which represents a 0.32% increase. This research contributes to understanding the effects of PM2.5 on mortality during a disaster and provides justification for environmental managers to monitor PM2.5 variability, not only hourly averages of PM2.5 concentration.

Application of ddPCR for detection of Enterococcus spp. in coastal water quality monitoring

Droplet digital polymerase chain reaction (ddPCR) was evaluated for the detection of fecal indicator bacteria (FIB), Enterococcus spp., in San Diego County beach water samples collected under diverse conditions, from multiple pollution sources, as part of regulatory monitoring activities over 20 months. Two US EPA-approved methods, qPCR (EPA 1609.1) and Enterolert (SM9230D), were used as reference comparator methods. A total of 361 samples were assayed by both ddPCR and qPCR and yielded an acceptable Index of Agreement (IA) of 0.89, based on EPA Site-Specific analysis guidelines. A Pearson's correlation coefficient of r = 0.87 (p < 0.001), further indicated a strong relationship between the methods results. From the 361 samples, 185 split samples with ddPCR and Enterolert values within the limits of quantification, were used as a ‘training’ data set to derive an intrinsic copy number equation (ICE) for scaling ddPCR gene copy number to Enterolert most probable number (MPN). Of the 1993 samples that comprised the complete ‘test’ data set assayed by ddPCR and Enterolert, 1086 generated results that fell within the limits of quantification for Enterolert and yielded an overall IA of 0.64. Re-analysis using median as a measure of central tendency to account for significant skewing of Enterolert data yielded an IA of 0.72. Beach grouping-specific IA values ranged from 0.63 to 0.93. Pearson's correlation coefficient, r, ranged from 0.13 to 0.94 within beach groupings and generated a combined value of 0.60 for all groupings. Using the ICE, a ddPCR advisory threshold of 1413 DNA copy number/100 mL was empirically determined to be the equivalent to the California Enterolert beach action threshold of 104 MPN/100 mL, based on comparison with all 1993 paired ddPCR and Enterolert results. Using the 1413 DNA copy number/100 mL as a beach action threshold for ddPCR resulted in a 90.4% agreement with Enterolert (6.0% false negative and 3.7% false positive). Together these findings support the conclusion that ddPCR readouts align closely with Enterolert MPN for identifying FIB exceedance levels of Enterococcus spp. in coastal waters of San Diego, CA.

Improving data reliability: A quality control practice for low-cost PM2.5 sensor network.

Low-cost air quality sensor networks have been increasingly used for high spatial resolution air quality monitoring in recent years. Ensuring data reliability during continuous operation is critical for these sensor networks. Using particulate matter sensor as an example, this study reports a data quality control method, including sensor selection, pre-calibration, and online inspection. It was used in developing and operating the dense low-cost particle sensor networks in two Chinese cities. Firstly, seven mainstream sensors were tested and one model of particle sensor was selected due to its better linearity and stability. For a batch of sensors of the same model, although they were calibrated after manufactured, there are differences in response toward the same concentration of pollutants. The systematical variation of sensors was corrected and unified through pre-calibration. After deploying them in the field, a data analysis method is established for online inspecting their working status. Using data from these sensors, it evaluates parameters such as intraclass correlation coefficients and normalized root mean square error. These two metrics help to construct a two-dimensional coordinate system and to classify sensors into four status, including normal, fluctuation, hotspots, and malfunction. During a one-month operation in the two cities, 8 (out of 82) and 10 (out of 59) sensors with suspected malfunctions were screened out for further on-site inspection. Moreover, the sensor networks show potential in identifying illegal emission sources that cannot be typically detected by sparse regulatory air quality monitoring stations.

Methane emissions from an oil sands tailings pond: a quantitative comparison of fluxes derived by different methods

Abstract. Tailings ponds in the Alberta oil sands region are significant sources of fugitive emissions of methane to the atmosphere, but detailed knowledge on spatial and temporal variabilities is lacking due to limitations of the methods deployed under current regulatory compliance monitoring programs. To develop more robust and representative methods for quantifying fugitive emissions, three micrometeorological flux methods (eddy covariance, gradient, and inverse dispersion) were applied along with traditional flux chambers to determine fluxes over a 5-week period. Eddy covariance flux measurements provided the benchmark. A method is presented to directly calculate stability-corrected eddy diffusivities that can be applied to vertical gas profiles for gradient flux estimation. Gradient fluxes were shown to agree with eddy covariance within 18 %, while inverse dispersion model flux estimates were 30 % lower. Fluxes were shown to have only a minor diurnal cycle (15 % variability) and were weakly dependent on wind speed, air, and water surface temperatures. Flux chambers underestimated the fluxes by 64 % in this particular campaign. The results show that the larger footprint together with high temporal resolution of micrometeorological flux measurement methods may result in more robust estimates of the pond greenhouse gas emissions.

Wet grinding of invertebrate bulk samples – a scalable and cost-efficient protocol for metabarcoding and metagenomics

DNA metabarcoding is an efficient tool to characterize invertebrate species composition in environmental samples. Most metabarcoding protocols for invertebrate bulk samples start with sample homogenization, followed by DNA extraction, amplification of a specific marker region and sequencing on a high-throughput sequencer. Many of the above-mentioned laboratory steps have been verified thoroughly and best practice strategies exist. Giving the amount of research done to validate almost all laboratory steps of metabarcoding workflows it is surprising that there is no clear recommendation for the basis of almost all metabarcoding studies: the homogenization of samples itself. For homogenization, different devices are used that can be divided into two major categories: bead mills and blenders. While bead-mills accelerate small, hard particles in a closed container or tube to break down specimens into small tissue fragments, blenders work with a rapidly rotating blades that reliably slice specimens as well as other substrate of the sample. Both methods are currently used in metabarcoding studies and have downsides to consider. Bead-mills rely on single-use plastics and therefore produce a lot of waste and are expensive. In addition to that, processing times can go up to 30 minutes making them unsuitable for large scale studies. Blenders on the other hand offer the opportunity to be cleaned and can handle larger sample volumes in shorter time, with an increased risk of cross-contamination. We here aimed to develop a fast, robust, cheap and reliable sample homogenization protocol that overcomes the above-mentioned limitations of both methods, i.e. does not produce difficult to discard waste and avoid single-use plastics while reducing overall costs. We tested the performance of the new protocol using six sorted Malaise trap insect samples and six unsorted stream macroinvertebrate kick-net samples. We used 14 technical replicates of each sample and many negative controls per sample (Fig. 1) to quantify impacts of i) insufficient homogenization and ii) possible sources of cross-contamination. Our results show that homogenization is sufficient after 3 minutes of homogenization. Rinsing the blender with water is sufficient in most cases but leads to low read-numbers in some of the negative controls. These could be further reduced by rinsing the blender with self-made drain-safe sterilization solution based on bleach but far less corrosive than pure bleach. Our results suggest that rinsing 1-2 times for 20 seconds is sufficient to avoid any cross-contamination. The improvements of the protocol in terms of speed, ease of handling, overall reduction of costs as well as the documented reliability and robustness make it an important candidate for sample homogenization after sampling in particular for large-scale and regulatory metabarcoding biodiversity assessments and monitoring programs.

Diversity of the insect pathogenic fungi in the genus Metarhizium in New Zealand

ABSTRACT Invertebrate-pathogenic fungi in the genus Metarhizium are commonly found throughout the world on a wide range of different arthropod hosts. Some strains have been developed as biopesticides and many others have shown potential for controlling important insect pests. Given the current interest in using these fungi, precise identification at species level is crucial, both for understanding their diversity and ecology and for regulatory approval and monitoring of new biopesticides. Metarhizium has undergone extensive systematic revision over the last decade, resulting in a large number of name changes and new species. This has created regulatory issues in New Zealand and importation of biocontrol strains has become difficult due to a lack of knowledge of which Metarhizium species are present in the country. This study identified Metarhizium isolates held in culture collections in New Zealand following analysis of sequence data from the ef-1α, β-tubulin, rpb1, and ITS regions. Our results show that M. anisopliae, M. brunneum, M. frigidum, M. novozealandicum, M. pemphigi, M. rileyi and M. robertsii occur naturally in New Zealand on native and introduced insect hosts. Exotic Metarhizium species from several countries, stored in New Zealand collections, include M. acridum, M. lepidiotae, M. majus and M. pingshaense.