How to use empirical data to improve transportation infrastructure risk assessment

Rainfall-induced hazards, such as landslides, debris flows, and floods cause significant damage to transportation infrastructure. However, an accurate assessment of rainfall-induced hazard risk to transportation infrastructure is limited by the lack of regional and asset-tailored vulnerability curves. This study aims to use multi-source empirical damage data to generate vulnerability curves and assess the risk of transportation infrastructure to rainfall-induced hazards. The methodology is exemplified through a case study for the Chinese national railway infrastructure. In doing so, regional and national-level vulnerability curves are derived based on historical railway damage records. This is combined with daily precipitation data and the railway infrastructure market value to estimate regional- and national-level risk. The results show large variations in the shape of the vulnerability curves across the different regions. The railway infrastructure in Northeast and Northwest China is more vulnerable to rainfall-induced hazards due to low protection standards. The expected annual damage (EAD) ranges from 1.88 to 5.98 billion RMB for the Chinese railway infrastructure, with a mean value of 3.91 billion RMB. However, the risk of railway infrastructure in China shows high spatial differences due to the spatially uneven precipitation characteristics, exposure distribution, and vulnerability curves. The South, East and Central provinces have a high risk to rainfall-induced hazards, resulting in an average EAD of 184 million RMB, 176 and 156 million RMB, respectively, whereas the risk in the Northeast and Northwest provinces are estimated to be relatively lower. The usage of multi-source empirical data offer opportunities to perform risk assessments that include spatial detail among regions. These risk assessments are highly needed in order to make effective decisions to make our infrastructure resilient.

Pharmacokinetic /Pharmacodynamic Considerations of Alternate Dosing Strategies of Tocilizumab in COVID-19

Tocilizumab is one of few treatments that have been shown to improve mortality in patients with COVID-19, but increased demand has led to relative global shortages. Recently, it has been suggested that lower doses, or fixed doses, of tocilizumab could be a potential solution to conserve the limited global supply while conferring equivalent therapeutic benefit to the dosing regimens studied in major trials. The relationship between tocilizumab dose, exposure, and response in COVID-19 has not been adequately characterized. There are a number of pharmacokinetic (PK) parameters which likely differ between patients with severe COVID-19 and patients in whom tocilizumab was studied during the FDA approval process. Likewise, it is unclear whether a threshold exposure is necessary for tocilizumab efficacy. The safety and efficacy of fixed versus weight-based dosing of tocilizumab has been evaluated outside of COVID-19, but it is uncertain if these observations are generalizable to severe or critical COVID-19. In the current review, we consider the potential advantages and limitations of alternative tocilizumab dosing strategies. Leveraging PK models and simulation analyses, we demonstrate that a fixed single dose of tocilizumab 400 mg is unlikely to produce PK exposures equivalent to those achieved in the REMAP-CAP trial, though weight-stratified dosing appears to produce more uniform exposure distribution. Data from current and future trials could provide PK/PD insight to better inform dosing strategies at the bedside. Ultimately, rational dosing strategies that balance available limited supply with patient needs are required.

Simulation study on the validity of the average risk approach in estimating population attributable fractions for continuous exposures

BackgroundThe population attributable fraction (PAF) is an important metric for estimating disease burden associated with causal risk factors. In an International Agency for Research on Cancer working group report, an approach was introduced to estimate the PAF using the average of a continuous exposure and the incremental relative risk (RR) per unit. This ‘average risk’ approach has been subsequently applied in several studies conducted worldwide. However, no investigation of the validity of this method has been done.ObjectiveTo examine the validity and the potential magnitude of bias of the average risk approach.MethodsWe established analytically that the direction of the bias is determined by the shape of the RR function. We then used simulation models based on a variety of risk exposure distributions and a range of RR per unit. We estimated the unbiased PAF from integrating the exposure distribution and RR, and the PAF using the average risk approach. We examined the absolute and relative bias as the direct and relative difference in PAF estimated from the two approaches. We also examined the bias of the average risk approach using real-world data from the Canadian Population Attributable Risk of Cancer study.ResultsThe average risk approach involves bias, which is underestimation or overestimation with a convex or concave RR function (a risk profile that increases more/less rapidly at higher levels of exposure). The magnitude of the bias is affected by the exposure distribution as well as the value of RR. This approach is approximately valid when the RR per unit is small or the RR function is approximately linear. The absolute and relative bias can both be large when RR is not small and the exposure distribution is skewed.ConclusionsWe recommend that caution be taken when using the average risk approach to estimate PAF.

Analisis Dosis Paparan Radiasi Pada General X-Ray II Di Instalasi Radiologi Rumah Sakit Muhammadiyah Semarang

Background: This study analyzes the Radiation Dose of the General X-ray Radiology Installation at Roemani Hospital Muhammadiyah Semarang to determine the dose received by the radiographer, the community around the room and to know the value of the effectiveness of radiation protection and to determine the pattern of radiation exposure distribution in the general X-ray radiology installation room II.Methods: Measurements were taken during general X-ray exposure and without exposure using a 451P ion chamber survey. Measurement of dose data received by the radiographer and the community around the room is taken at the point of the operator’s room, service room, waiting room. As for the measurement of the effectiveness of radiation protection taken at the point in the operator’s room and the general X-ray II and the radiation distribution pattern taken at points A, B, C, D and E with a distance of 40 cm, 80 cm and 120 cm in the room general X-ray II.Result: The result of measurements in the operator room are 0.0354 µSv / hour, waiting rooms with a distance of 3.5 m at 0.0146 µSv / hour, in the service room and waiting room with a distance of 8 m at 0 µSv / hour. The value of the effectiveness of radiation protection in the operator station is 83.33% and the general X-ray II door is 84.09%.Conclusions: Based on the results of the data obtained the value of the dose received and the value of effectiveness is quite safe from excessive radiation exposure. The radiation distribution pattern, the farther the distance from the radiation source, the measured radiation exposure value will be lower.

Modeling Light Exposure of Quartz Grains During Mortar Making: Consequences for Optically Stimulated Luminescence Dating

ABSTRACTDating lime mortar shows great potential for establishing the chronology of a construction. The basic premise of mortar dating by optically stimulated luminescence (OSL) is that quartz in the sand used for making mortar has been optically zeroed during the preparation process (optical bleaching). The moment to be dated is the last exposure of sand grains to light, before being embedded within the masonry and hidden from light. However, the main problem is the frequent partial and heterogeneous bleaching of grains, and this led us to use the single grain technique (SG-OSL) systematically. Some theoretical and experimental aspects of a new statistical treatment (the EED model, as exponential exposure distribution) are detailed and discussed. Our experience shows that SG-OSL dating of mortars is successful in a majority of situations. In a minority of cases (around 15%) difficulties originate when there is inappropriate OSL behavior of grains, and thus OSL dating is not possible. In the other cases, good agreement was obtained between OSL ages and the reference ones for a series of samples from a variety of ages and situations, even in the case of poorly bleached material. Anyway, the present situation of OSL dating methodology justifies the systematic use of SG-OSL in the dating of masonry today.

Intelligence gain and social cost savings attributable to environmental lead exposure reduction strategies since the year 2000 in Flanders, Belgium

Background Recent lead (Pb) exposure reduction strategies enabled to lower children’s blood lead levels (B-Pb) worldwide. This study reports the estimated intelligence gain and social cost savings attributable to recent exposure reduction based on reported B-Pb levels observed in adolescents sampled within the framework of the Flemish Environment and Health Studies (FLEHS, Belgium), i.e. in 2003–2004 (FLEHSI), in 2008–2009 (FLEHSII), and in 2013–2014 (FLEHSIII). Methods Intelligence Quotient (IQ) loss per 100,000 individuals - attributable to B-Pb above 20 μg/L - was estimated based on widely accepted dose response functions between children’s B-Pb and IQ (− 1.88 IQ points for a duplication in B-Pb from 20 μg/L onwards; 95% Confidence Interval (CI): − 1.16;-2.59) and B-Pb exposure distribution parameters of FLEHS studies. The results were translated to the Flemish population of 15-year-olds. Given a 3-year time gap between subsequent sampling periods, the exposure distribution of each study was assumed 3 years prior to the study as well. Economic impact was estimated based on expected decrease in lifetime earnings (€ 19,464 per decreasing IQ point in 2018). Results The percentage of the adolescent population exceeding a B-Pb of 20 μg/L decreased from 57% (FLEHSI) to 23% (FLEHSII), and even further to 2.5% (FLEHSIII). The estimated IQ loss per 100,000 individuals was 94,280 (95% CI: 58,427-130,138) in FLEHSI, 14,993 (95% CI: 9289-20,695) in FLEHSII, and 976 (95% CI: 604–1347) in FLEHSIII. This translates into a total loss of 378,962 (95%CI: 234,840-523,091) IQ points within the Flemish population of 15-year-olds between 2000 and 2014. Assuming that current exposure levels do not reincrease, the expected IQ loss during the subsequent period of 15 years is estimated to be maximally 10,275 (95%CI: 6363-14,182) points. Conclusions 7176 (95%CI: 4447-9905) million € of social cost savings were achieved by Pb reduction strategies in Flanders over 15 years. If current exposure levels further reduce to B-Pb below 20 μg/L for the whole population, social cost savings may increase up to 7376 (95%CI: 4571-10,181) million €. Given the relatively low lead contamination in Flanders, the global impact of ongoing reduction strategies is expected to be tremendous.

Accelerated lung function decline in an aluminium manufacturing industry cohort exposed to PM2.5: an application of the parametric g-formula

ObjectiveOccupational dust exposure has been associated with accelerated lung function decline, which in turn is associated with overall morbidity and mortality. In the current study, we assess potential benefits on lung function of hypothetical interventions that would reduce occupational exposure to fine particulate matter (PM2.5) while adjusting for the healthy worker survivor effect.MethodsAnalyses were performed in a cohort of 6485 hourly male workers in an aluminium manufacturing company in the USA, followed between 1996 and 2013. We used the parametric g-formula to assess lung function decline over time under hypothetical interventions while also addressing time-varying confounding by underlying health status, using a composite risk score based on health insurance claims.ResultsA counterfactual scenario envisioning a limit on exposure equivalent to the 10th percentile of the observed exposure distribution of 0.05 mg/m3 was associated with an improvement in forced expiratory volume in one second (FEV1) equivalent to 37.6 mL (95% CI 13.6 to 61.6) after 10 years of follow-up when compared with the observed. Assuming a linear decrease and (from NHANES reference values), a 20 mL decrease per year for a 1.8 m-tall man as they age, this 37.6 mL FEV1 loss over 10 years associated with observed exposure would translate to approximately a 19% increase to the already expected loss per year from age alone.ConclusionsOur results indicate that occupational PM2.5 exposure in the aluminium industry accelerates lung function decline over age. Reduction in exposure may mitigate accelerated loss of lung function over time in the industry.

Assessment of risk to hoary squash bees (Peponapis pruinosa) and other ground-nesting bees from systemic insecticides in agricultural soil

Using the hoary squash bee (Peponapis pruinosa) as a model, we provide the first probabilistic risk assessment of exposure to systemic insecticides in soil for ground-nesting bees. To assess risk in acute and chronic exposure scenarios in Cucurbita and field crops, concentrations of clothianidin, thiamethoxam and imidacloprid (neonicotinoids) and chlorantraniliprole (anthranilic diamide) in cropped soil were plotted to produce an environmental exposure distribution for each insecticide. The probability of exceedance of several exposure endpoints (LC50s) was compared to an acceptable risk threshold (5%). In Cucurbita crops, under acute exposure, risk to hoary squash bees was below 5% for honey bee LC50s for all residues evaluated but exceeded 5% for clothianidin and imidacloprid using a solitary bee LC50. For Cucurbita crops in the chronic exposure scenario, exposure risks for clothianidin and imidacloprid exceeded 5% for all endpoints, and exposure risk for chlorantraniliprole was below 5% for all endpoints. In field crops, risk to ground-nesting bees was high from clothianidin in all exposure scenarios and high for thiamethoxam and imidacloprid under chronic exposure scenarios. Risk assessments for ground-nesting bees should include exposure impacts from soil and could use the hoary squash bee as an ecotoxicology model.