Comparative study of plasma lead levels in the staff of Dandy Zinc Factory of Zanjan and in normal individuals

Pollution is a global problem which affects various human population functions. Despite the decline in plasma lead (Pb) levels among the general population during the past 20 years, this metal continues to be a public health concern for individuals with past and present exposures. The objective of this study was to determine blood lead levels (BPbL) in the staff of Dandy Zinc Company and compare them to control subjects. The test group included 40 staff of Dandy Zinc Company of Zanjan, while controls were selected from general population. Five milliliters of blood and plasma was sent to Atomic Energy Organization of Iran (AOEI) reference lab to measure BPbL by Flameless Atomic Absorption. BPbL in test group (16.6 + 8.18 µg dL^?1) was significantly higher than control (10.47 + 2.10 µg dL^?1). In both groups BPbL was significantly higher in smokers than non-smokers. Blood lead levels in molding workers were significantly higher than other workers. BPbL in exposed workers were directly related to duration of work and age. Data indicate Pb exposure was of significant magnitude to be a public health concern especially in zinc-and Pb-related industries.     

A STOCHASTIC DYNAMIC PROGRAMMING MODEL FOR THE OPTIMUM OPERATION OF A MULTI-PURPOSE RESERVOIR1

ABSTRACT: The main objective of this paper is to present a stockastic dynamic programming model useful in determining the optimal operating policy of a single multipurpose surface reservoir. It is the unreliability of forecasting the amount of future streamflow which makes the problem of a reservoir operation a stochastic process. In this paper the stochastic nature of the streamflow is taken into account by considering the correlation between the streamflows of each pair of consecutive time intervals. This interdependence is used to calculate the probability of transition from a given state and stage to its succeeding ones. A dynamic programming model with a physical equation and a stochastic recursive equation is developed to find the optimum operational policy. For illustrative purposes, the model is applied to a real surface water reservoir system.     

Evaluation of delta-aminolevulinic acid levels in the urine of Angooran Lead & Zinc Company staff

Currently, attention has shifted to chronic or subclinical disorders attributed to lead (Pb) exposure. The aim of this study was to determine delta-aminolevulinic acid (δ-ALA) levels in urine of Angooran Lead &; Zinc Company workers. This cross-sectional study was conducted on 170 workers, in which 24 h urinary samples were collected and δ-ALA levels were measured spectrophotometrically. Questionnaire forms were completed indicating age, location, and duration of work. The mean δ-ALA level in urine was 5.44 mg L^?1. δ-ALA levels were correlated with age, location, and duration of work in the company. The mean δ-ALA level in the urine of workers was in the upper limit of normal ranges. δ-ALA level in urine may not be the best discriminating factor of Pb exposure from the baseline to the high levels, but is recommended as a regular and routine test for all Pb-exposed workers in addition to the measurement of Pb in blood for subjects with higher δ-ALA levels.     

Nervous signs of salt poisoning in Wistar rats

Acute salt poisoning in animals leads to inflammation, gastroenteritis, and diarrhea. Neurological signs include blindness, muscular paralysis, deafness, and general weakness. In this study, nervous signs of salt poisoning in rats were examined. Twenty five Wistar rats, weighing 200 ± 20 g, were allocated randomly to five groups: 1%, 2%, 3%, and 4% salt solution and control group drank tap water. Following salt solution consumption, physical and neurological examinations were performed twice daily. One percent salt solution did not produce significant neurological signs, whereas consuming 2% salt solution was associated with different nervous system effects including muscle tremor, lethargy, hyperreflexia, imbalance in movement, and rotatory rhythmic movements. Consumption of 3% and 4% salt solutions led to reduction in hearing acuity, deafness, blindness, lethargy, severe complications, intracranial hemorrhage, and mortality in a period less than one week. Consuming salt solutions higher than 1% was associated with continuous water loss, dehydration, and weight loss and concordant with these changes, hypernatremia and hyperosmolarity occurred. Decrease in sensitivity to stimuli, irritability, disorientation and incoordination, involuntary movements, ataxia, sensory and motor disturbances, blindness, weakness, respiratory distress, colonic seizures and coma, sudden and unexplained deaths were observed in affected animals.     

Determination of tolerable and toxic salt concentrations in drinking water in rat,pig, and rabbit

In some geographical areas human and animal populations are compelled to use salty water. In this study, tolerable and toxic salt concentrations were evaluated in rat, pig, and rabbit. Ninety Wistar rats weighing approximately 250 g were allocated to nine groups for study. For treatment, distilled water, 0.5, 1, 1.2, 1.4, 1.6, 1.8 or 2% salt (NaCl) concentrations were consumed by test groups, while the control group consumed Zanjan potable water. All animals were observed twice daily for mortality or evidence of morbidity. Serum sodium levels and plasma osmolarity were measured at the onset of experiment and 120 h later. Similar experimental conditions were employed in pig and rabbit. Rat tolerated 0.5, 1, and 1.2% NaCl concentrations in drinking water but higher concentrations were toxic and life threatening, accompanied by significantly increased serum sodium levels and plasma osmolarity. This study showed that pig was the most sensitive and rabbit the most resistant species to different NaCl concentrations. Although NaCl concentrations lower than 1.4% was considered as tolerable in rat, the animal health was affected. NaCl concentrations of 1.4% and higher may jeopardize animal health and were considered as toxic amounts.     

Simultaneous monitoring of SARS-CoV-2, bacteria,and fungi in indoor air of hospital: a study on Hajar Hospital in Shahrekord,Iran

The novel SARS-CoV-2 outbreak was declared as pandemic by the World Health Organization (WHO) on March 11, 2020. Understanding the airborne route of SARS-CoV-2 transmission is essential for infection prevention and control. In this study, a total of 107 indoor air samples (45 SARS-CoV-2, 62 bacteria, and fungi) were collected from different wards of the Hajar Hospital in Shahrekord, Iran. Simultaneously, bacterial and fungal samples were also collected from the ambient air of hospital yard. Overall, 6 positive air samples were detected in the infectious 1 and infectious 2 wards, intensive care unit (ICU), computed tomography (CT) scan, respiratory patients’ clinic, and personal protective equipment (PPE) room. Also, airborne bacteria and fungi were simultaneously detected in the various wards of the hospital with concentrations ranging from 14 to 106 CFU m^?3 and 18 to 141 CFU m^?3, respectively. The highest mean concentrations of bacteria and fungi were observed in respiratory patients’ clinics and ICU wards, respectively. Significant correlation (p < 0.05) was found between airborne bacterial concentration and the presence of SARS-CoV-2, while no significant correlation was found between fungi concentration and the virus presence. This study provided an additional evidence about the presence of SARS-CoV-2 in the indoor air of a hospital that admitted COVID-19 patients. Moreover, it was revealed that the monitoring of microbial quality of indoor air in such hospitals is very important, especially during the COVID-19 pandemic, for controlling the nosocomial infections.

     

Salt poisoning blindness in wistar rat,rabbit, and pig

The objective of this study was to determine the ocular changes leading to blindness following different salt concentration consumption in Wistar rats. Test groups consumed 1, 2, 3, 3.5, or 4% salt concentration respectively as potable water, while the control group used tap water. Ophthalmic examinations with a slit-lamp and fundus camera were performed. Lack of eye response to light and manual stimuli were considered as blindness criteria. Similar experimental conditions were performed in pigs and rabbits. Short duration consumption of 1 or 2% salt concentrations did not produce any detectable ocular signs, whereas long duration consumption of 2% salt concentration induced prominent ocular signs. After 3–4 days of consuming 3% and higher salt concentrations, retinal and vitreous hemorrhages, posterior vitreous detachment PVD, and retinal detachment were observed. The following ocular changes included conjunctivital injection, cornea and lens opacities, swelling of the optic disc, blindness, vitreous collapse, and finally phthisis bulbi. Salt poisoning led to hypernatremia and hyperosmolarity. Due to hyperosmolarity, the vitreous lost some of its fluid contents and vitreous shrinkage resulted in vascular damage, retinal and vitreous hemorrhage, PVD, and retinal detachment. In addition, conjunctivitis, corneal and lens opacities, swelling of the optic disc, blindness, vitreous collapse, and finally phthisis bulbi was evident.     

Iodine deficiency status in the WHO Eastern Mediterranean Region: a systematic review

Iodine deficiency is a global public health issue because iodine plays a major role in the thyroid hormone synthesis and is essential for normal neurological development. This review summarizes the publications on iodine status in the WHO Eastern Mediterranean Region (EMR) countries. All related studies available in main national and international databases were systematically searched using some specific keywords to find article published between 1909 and 2015. The prevention of iodine deficiency disorders (IDDs) in the WHO EMR countries is currently under control without significant side effects. Mild to severe IDDs exist in some countries of the Middle East, due to lack of effective iodine supplementation program, but the Islamic Republic of Iran, Jordan, Bahrain and Tunisia have achieved the goal of universal salt iodization. Overall, despite enormous efforts to control IDDs, still IDD remains a serious public health problem in some countries of the region, requiring urgent control and prevention measures.     

Distribution and origin of potentially toxic elements in a multi-aquifer system

Environmental Science and Pollution Research - Pollution of the potentially toxic elements (PTEs) is a major concern in the metal ore-mining environment. Active polymetallic industries and mines...     

Origin and spatial–temporal distribution of faecal bacteria in a bay of Lake Geneva, Switzerland

The origin and distribution of microbial contamination in Lake Geneva's most polluted bay were assessed using faecal indicator bacteria (FIB). The lake is used as drinking water, for recreation and fishing. During 1 year, water samples were taken at 23 points in the bay and three contamination sources: a wastewater treatment plant (WWTP), a river and a storm water outlet. Analyses included Escherichia coli, enterococci (ENT), total coliforms (TC), and heterotrophic plate counts (HPC). E. coli input flux rates from the WWTP can reach 2.5 x 10(10) CFU/s; those from the river are one to three orders of magnitude lower. Different pathogenic Salmonella serotypes were identified in water from these sources. FIB levels in the bay are highly variable. Results demonstrate that (1) the WWTP outlet at 30 m depth impacts near-surface water quality during holomixis in winter; (2) when the lake is stratified, the effluent water is generally trapped below the thermocline; (3) during major floods, upwelling across the thermocline may occur; (4) the river permanently contributes to contamination, mainly near the river mouth and during floods, when the storm water outlet contributes additionally; (5) the lowest FIB levels in the near-surface water occur during low-flow periods in the bathing season.