Modeling regional impacts of climate teleconnections using functional data analysis

Teleconnections are quasi-periodic changes in atmospheric circulation that oscillate over long periods of time and impact climate over large regions. These patterns are often linked to long-term variations in climate and extreme weather events and may explain regional differences in climate vulnerability. We apply methods of functional data analysis to examine regional impacts of teleconnections on climate in British Columbia, Canada, between 1951 and 2000. We focus on monthly mean temperature as an overall determinant of crop growth and apply functional principal components analysis (FPCA) to study variations in the impacts of four major teleconnection indices affecting the Northern Hemisphere (the Southern Oscillation Index, the Pacific North American (PNA), Pacific Decadal Oscillation, and the North American Oscillation indices). Two challenges we consider are that the impacts of teleconnections cannot be observed directly and that fine scale data required to study regional variations may come from different sources with highly varied records. We first fit thin-plate regression splines to the raw data to construct complete series of pseudo-data at fixed grid points. Regression models incorporating Bayesian P-splines were then fit to the pseudo-data to estimate the impacts of the four teleconnections over time. Finally, FPCA was then applied to study regional variations in these effects. Our analysis identified strong variations in mean temperature associated with the PNA. The resulting spatial patterns also reveal areas of increased/decreased temperature variability that may have higher climate risk or be suitable for expansion of agricultural activity.     

Considerations for using alternative technologies in nutrient management on Cape Cod: Beyond cost and performance

Mitigating non-point source nitrogen in coastal estuaries is economically, environmentally, logistically, and socially challenging. On Cape Cod, Massachusetts, nitrogen management includes both traditional, centralized wastewater treatment and sewering as well as a number of alternative technologies. We conducted semi-structured interviews with 37 participants from governmental and non-governmental organizations as well as related industries to identify the barriers and opportunities for the use of alternative technologies to mitigate nitrogen pollution. The interviews were recorded, transcribed, and then analyzed using content analysis and rhetorical analysis. Cost and technical capacity to reduce nitrogen were the most discussed considerations. Beyond those, there were a slew of additional considerations that also impacted whether a technology would be installed, permitted, and socially accepted. These included: maintenance and monitoring logistics, comparisons to sewering, co-benefits, risk/uncertainty, community culture, extent of public engagement, permitting/regulatory challenges, and siting considerations. The insights about these additional considerations are valuable for transferring to other coastal areas managing nutrient impairments that may have not yet factored in these considerations when making decisions about how to meet water quality goals.     

Evaluating portable infrared spectrometers for measuring the silica content of coal dust

Miners face a variety of respiratory hazards while on the job, including exposure to silica dust which can lead to silicosis, a potentially fatal lung disease. Currently, field-collected filter samples of silica are sent for laboratory analysis and the results take weeks to be reported. Since the mining workplace is constantly moving into new and often different geological strata with changing silica levels, more timely data on silica levels in mining workplaces could help reduce exposures. Improvements in infrared (IR) spectroscopy open the prospect for end-of-shift silica measurements at mine sites. Two field-portable IR spectrometers were evaluated for their ability to quantify the mass of silica on filter samples loaded with known amounts of either silica or silica-bearing coal dust (silica content ranging from 10-200 μg/filter). Analyses included a scheme to correct for the presence of kaolin, which is a confounder for IR analysis of silica. IR measurements of the samples were compared to parallel measurements derived using the laboratory-based U.S. Mine Safety and Health Administration P7 analytical method. Linear correlations between Fourier transform infrared (FTIR) and P7 data yielded slopes in the range of 0.90-0.97 with minimal bias. Data from a variable filter array spectrometer did not correlate as well, mainly due to poor wavelength resolution compared to the FTIR instrument. This work has shown that FTIR spectrometry has the potential to reasonably estimate the silica exposure of miners if employed in an end-of-shift method.     

Cost–benefit analysis of beach-cast harvest: Closing land-marine nutrient loops in the Baltic Sea region

Harvesting beach-cast can help mitigate marine eutrophication by closing land-marine nutrient loops and provide a blue biomass raw material for the bioeconomy. Cost–benefit analysis was applied to harvest activities during 2009–2018 on the island of Gotland in the Baltic Sea, highlighting benefits such as nutrient removal from the marine system and improved recreational opportunities as well as costs of using inputs necessary for harvest. The results indicate that the activities entailed a net gain to society, lending substance to continued funding for harvests on Gotland and assessments of upscaling of harvest activities to other areas in Sweden and elsewhere. The lessons learnt from the considerable harvest experience on Gotland should be utilized for developing concrete guidelines for carrying out sustainable harvest practice, paying due attention to local conditions but also to what can be generalized to a wider national and international context.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01641-8.     

An investigation into the anthropogenic nexus among consumption of energy,tourism, and economic growth: do economic policy uncertainties matter?

Environmental Science and Pollution Research - Global warming has been a pressing issue for the past decade as various economic activities have been flagged and are expected to reduce emissions....     

Dissolved saxitoxin causes transient inhibition of sensorimotor function in larval Pacific herring (<Emphasis Type="Italic">Clupea harengus pallasi</Emphasis>)

Herring (Clupea harengus pallasi) spawning sites in Puget Sound, Washington overlap spatially and temporally with blooms of Alexandrium catenella, a toxic dinoflagellate species responsible for paralytic shellfish poisoning. Consequently, newly hatched herring larvae may be regularly exposed to the suite of dissolved paralytic shellfish toxins that are released into the water column from toxic cells during blooms. To date, virtually nothing is known about the impacts of these neurotoxins on early developmental stages of marine fish. In the present study, herring larvae at three ages, 0 days post hatch (dph), 4 dph, and 11 dph, were exposed to dissolved saxitoxin (STX) in 24-h and multi-day exposures. All larvae were examined for sensorimotor function (i.e. spontaneous swimming behavior and touch response). Significant reductions in spontaneous and touch-activated swimming behavior occurred within 1 h of exposure. EC₅₀s at 1 h of exposure were 1,500, 840, and 700 μg STX equiv. l⁻¹ for larvae introduced to STX at 0, 4, and 11 dph, respectively. This progressive age-specific increase in STX-induced paralysis suggests that older larvae were more sensitive to the toxin than younger larvae. Interestingly, herring larvae at all ages exhibited a significant degree of neurobehavioral recovery within 4–24 h of continuous exposure relative to the 1-h time point. This recovery of normal motor behaviors was not observed in previous studies with freshwater zebrafish (Danio rerio) larvae under the same continuous exposure conditions, suggesting that an adaptive detoxification or toxin sequestration mechanism may have evolved in some species of marine fish larvae. Our data reveal that (1) dissolved STX is bioavailable to marine finfish larvae, (2) the toxin is a paralytic agent with potencies that differ between developmental stages, and (3) STX-induced sensorimotor inhibition occurs rapidly but is transient in marine larvae. Collectively, these results suggest that dissolved algal toxins may have important sublethal effects on marine fish populations.     

Wide-spread genetic variability and the paradox of effective population size in the gag,Mycteroperca microlepis,along the West Florida Shelf

Wide-ranging marine species are often described as having a low effective population size (N _e) to census size (N) ratio. This genetic phenomenon is typically attributed to large variation among individuals in reproductive success because of the high mortality rates and unpredictable environments associated with larval dispersal. In this study, we examined patterns of genetic variation in gag (Mycteroperca microlepis) on the West Florida Shelf across year classes of post-settlement juveniles and spawning adults. With no significant genetic differentiation among year classes despite varying recruitment dynamics, little evidence for chaotic genetic patchiness, and no truncation of adult genetic diversity in subsequent juvenile cohorts, there was little support for large variation among individual in reproductive success contributing to a low N _e/N ratio. In fact, the consistent lack of significant differences in annual recruitment classes indicated that reproductive success among individuals was resistant to skewing. Among the various evolutionary forces that may be affecting N _e, changes to demography due to fishing pressure are posited as a likely mechanism affecting current levels of genetic variation.     

Assessment of dermal exposure to benzene and toluene in shoe manufacturing by activated carbon cloth patches

OBJECTIVES: The aim of this investigation was to use activated carbon cloth (ACC) patches to study the probability and extent of dermal exposure to benzene and toluene in a shoe factory. METHODS: Inhalation and dermal exposure loading were measured simultaneously in 70 subjects on multiple days resulting in 113 observations. Dermal exposure loading was assessed by ACC patches attached to likely exposed skin areas (e.g. the palm of the hand and abdomen). A control patch at the chest and an organic vapor monitor (OVM) were used to adjust the hand and abdomen patches for the contribution from the air through passive absorption of benzene and toluene on the ACC patches. Systemic exposure was assessed by quantification of unmetabolized benzene (UBz) and toluene (UTol) in urine. RESULTS: Mean air concentrations for the study population were 1.5 and 7.5 ppm for benzene and toluene, respectively. Iterative regression analyses between the control patch, OVM and the dermal patches showed that only a small proportion of the ACC patches at the hand had likely benzene (n = 4; mean 133 microg cm(-2) h(-1)) or toluene (n = 5; mean 256 microg cm(-2) h(-1)) contamination. Positive patches were exclusively observed among subjects performing the task of gluing. Significant dermal exposure loading to the abdomen was detected only for toluene (n = 2; mean 235 microg cm(-2) h(-1)). No relation was found between having a positive hand or abdomen ACC patch and UBz or UTol levels. In contrast a strong association was found between air levels of benzene (p = 0.0016) and toluene (p < 0.0001) and their respective urinary levels. CONCLUSIONS: ACC patches are shown to be a useful technique for quantifying the probability of dermal exposure to organic solvents and to provide estimates of the potential contribution of the dermal pathway to systemic exposure. Using ACC patches we show that dermal exposure to benzene and toluene in a shoe manufacturing factory is probably rare, and when it occurred exposures were relatively low and did not significantly contribute to systemic exposure.