Exploring Potential Human Health Risks Linked to Heavy Metal(Loid)s in Dietary Fishes: Utilizing Data-Driven and Computational Modelling Approaches.

There are significant concerns about the risks to human health posed by metal(loid) contamination in dietary fishes in Bangladesh. Therefore, this study aimed to evaluate heavy metal(loid) contamination in fish and their associated health risks using published data from 2000 to 2022. Additionally, the safe limit of fish consumption was estimated using the target hazard quotient (THQ) followed by computational modelling and artificial neural networks (ANN). Results showed that freshwater and herbivorous fishes pose the least non-cancer risks, whereas saltwater and carnivorous fishes pose the highest non-cancer risks to Bangladeshi consumers. However, freshwater and omnivorous fish consumption pose the highest cancer risks compared to all studied metal(loid)s. In particular, among the heavy metal(loid)s, As, Cr, Hg, and Ni pose significant cancer and non-cancer risks to Bangladeshi consumers. On the contrary, the ANN and Decision tree regression (DTR) characterized the dataset, simulation model, or data testing condition, reaching 94.7% accuracy and allowing us to measure the safest fish consumption limit. The herbivorous fishes are less contaminated and allow greater consumption (175.09 g day-1). Contrarily, the allowable intake rates of carnivorous and omnivorous fishes are 153.05 and 168.63 g day-1, respectively. Besides, the safe consumption rate of saltwater fishes was 156.51 g day-1, which was lower than freshwater (180.59 g day-1) and euryhaline fishes (182.17 g day-1). Therefore, this study will assist fish consumers in selecting less contaminated fish, ensuring safe consumption levels, and ultimately reducing health risks associated with metal(loid) contamination in fish.

A new approach to establish safe levels of available metals in soil with respect to potential health hazard of human.

Safe levels of extractable pollutant elements in soil have not been universally established. Prediction of metal solubility in polluted soils and the subsequent transfer of these metals from soil pore water to the human food supply via crops are required for effective risk assessment from polluted soils. Thus an attempt has been made to develop a novel approach to protect human health from exposure to toxic metals through assessing risk from metal polluted soils utilised for agriculture. In this study, we assess the relative efficacy of various forms of 'free ion activity model' (FIAM) for predicting the concentration of cadmium (Cd), lead (Pb), nickel (Ni), zinc (Zn) and copper (Cu) in spinach and wheat as example crops, thereby providing an assessment of risk to human health from consumption of these crops. Free metal ion activity in soil solution was estimated using the Windermere Humic Aqueous Model VII (WHAM-VII) and the Baker soil test. Approximately 91, 81, 75, 94 and 70% of the variability in Cd, Pb, Ni, Zn and Cu content, respectively, of spinach could be described by a FIAM using an estimate of the free ion activity of the metals provided by WHAM-VII. Owing to the different concentration of ethylenediamine tetraacetic acid (EDTA) and diethylenetriamine pentaacetic acid (DTPA) used in the present experiment, higher prediction coefficients were obtained using EDTA (0.05 M), rather than DTPA (0.005 M), as the metal extractant in an integrated solubility-FIAM model. Out of three formulations, the FIAM, based on free ion activity of metals in soil pore water, determined from solution extracted with Rhizon samplers, was distinctly superior to the other formulations in predicting metal uptake by spinach and wheat. A safe level of extractable metal in soil was prescribed using a hazard quotient derived from predicted plant metal content and estimated dietary intake of wheat and spinach by a human population. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12665-021-09988-7.

Caffeine Consumption Habits of New Zealand Tertiary Students.

Adverse effects associated with excessive caffeine consumption combined with increasing numbers and availability of caffeine-containing products are causes for concern. Tertiary students may be at increased risk of consuming excessive amounts of caffeine due to seeking caffeinated products with well-known wakefulness effects and cognitive benefits. This study explored caffeine consumption habits of New Zealand tertiary students (317; ≥16-years) using a previously validated caffeine consumption habits (CaffCo) questionnaire. Most (99.1%) regularly consumed caffeinated products, especially chocolate, coffee and tea, with coffee, tea and energy drinks contributing most to total caffeine intake. Median estimated caffeine intake was 146.73 mg·day-1, or 2.25 mg·kgbw-1·day-1. Maximum and minimum intakes were 1988.14 mg·day-1 (23.51 mg·kgbw-1·day-1) and 0.07 mg·day-1 (0.02 mg·kgbw-1·day-1), respectively. One-third (34.4%) of caffeine consumers ingested caffeine above the adverse effect level (3 mg·kgbw-1·day-1) and 14.3% above the safe limit (400 mg·day-1). Most caffeine consumers (84.7%), reported experiencing at least one 'adverse symptom' post-caffeine consumption, of which 25.7% reported effects leading to distress or negatively impacting their life. Experiencing 'adverse symptoms' did not, however, curtail consumption in the majority of symptomatic participants (~77%). Public health initiatives directed at tertiary students may be important to reduce potential caffeine-related harm.

Determination of safe limit for arsenic contaminated irrigation water using solubility free ion activity model (FIAM) and Tobit Regression Model.

Irrigation water contaminated with arsenic acts as a potent source of contamination to humans through water-soil-crop-food transfer so quantification of safe limit for irrigation water is also critical. A pot experiment was conducted to determine the safe limit for As contaminated irrigation water with two soil types (alluvial and red) using ten levels of contaminated irrigation water (0, 0.25, 0.5, 0.75, 1.0, 1.25, 1.50, 1.75, 2.0, 2.25 mg L-1), applied 5 times in rice (Variety: Sushak Samrat),used as a test crop. The results reveal that the different fractions of arsenic in terms of its profusion followed the order F4 > F2 > F5 > F3 > F1 and F4 > F3 > F2 > F5 > F1 across all the doses of As for alluvial soil and red soil respectively. The safe limit of irrigation water in terms of risk assessment expressed as Hazard Quotient (HQ) was at 0.75 mg L-1 and the solubility FIAM can effectively predict the As content in rice grain in both the soils. The Tobit Regression Model in alluvial soil quantified the safe limit for As in irrigation water from 1.20 to 0.10 mg L-1 for available soil As 0.25-3.0 mg kg-1 and in red soil, the range was from 0.10 to 0.40 mg L-1 for soil As 1.0 to 0.25 mg kg-1 provided that the As content in rice grain is < 0.4 mg kg-1. This proved to be an effective protocol for estimation of safe limits after proper validation and calibration.

Safe Limit of Shortening of the Spinal Cord in Thoracolumbar Bivertebral Column Resections: An Experimental Study in Goats.

OBJECTIVE: To clarify the safe limit of shortening of the spinal cord in thoracolumbar bivertebral column resection in a goat model. METHODS: Ten healthy goats were selected for the experiment. Radiographs were taken before surgery to measure the height of T13, L1, and the initial osteotomy segment (distance from the lower end plate of T12 to the upper end plate of L2). A procedure of thoracolumbar bivertebral column resection (T13 and L1) was completed under the monitoring of somatosensory evoked potential (SSEP) monitoring. The SSEP measured after vertebral resection was set as the baseline. SSEPs decreased by 50% from the baseline amplitude and/or delayed by 10% relative to the baseline peak latency were set as positive results, indicating spinal cord injury. The initial height of the osteotomy gap was measured first and the spinal column was gradually shortened until the SSEP monitoring did not show a positive result. Then the height of the osteotomy gap was recorded again. The safe limit of shortening was measured and recorded when any morphologic change of the spinal cord was observed. Hindlimb function was evaluated by the Tarlov scores on day 2 postoperatively. RESULTS: The safe limit of shortening of the spinal cord in thoracolumbar bivertebral columns resection was 35.2 ± 2.6 mm, which was roughly equal to 127.6% of the mean osteotomy vertebral height and 57.1% of the initial osteotomy gap height. Pearson correlation test showed that the safe limit of shortening of the spinal cord was correlated with the height of T13, the height of L1, the mean height of T13 and L1, and the height of the initial osteotomy gap. CONCLUSIONS: The safe limit of shortening distance of the bivertebral column resection was roughly equal to 127.6% of the mean osteotomy vertebral height and 57.1% of the initial osteotomy gap height with good correlation. Moreover, the safe limit of shortening distance of the bivertebral column resection was longer than that in single vertebral column resection. Increasing the number of vertebrae resected may prevent spinal cord injury because of excessive shortening.

Hygiene at work: An engineering perspective on the development of hygiene science.

The present article examines the work of contemporary hygiene practitioners. Discussion converges from a broad examination of hygiene at work in our society serving the common good to occupational hygiene in the workplace. The article considers the expanding role of hygiene today, juxtaposed against the lack of awareness and perceptions of hygiene. It considers some of the current social challenges facing hygiene, perceptions of risk and problems specifically encountered by occupational hygienists.