環境および分析毒性学

Contrary to the old saying, children are not small adults. Children are different from adults in their response to environmental stressors because of their special body composition, which continuously changes as they grow. Children’s development at each stage of their life needs special consideration, especially that harmful exposures might impact their normal development, and increases their susceptibility to diseases later in life. This paper reviews children’s biological characteristics, and their normal developmental changes that make them more susceptible to environmental exposures. The paper will also discuss ways in which this normal development is influenced by environmental toxicants especially early life exposures, as well as the possibility of disease development. In this review, asthma is used as an example of a respiratory disease influenced by environmental toxicants, and methods of risk assessment used to predict such a disease are discussed.

Mangrove forests within the United Arab Emirates are being heavily exposed to anthropogenic contaminants due to pollution and urbanization. However, there is very limited research pertaining to this subject and the extent to which such mangroves can take up and store heavy metals is still unclear. In this research study, the concentrations of zinc, copper, lead and chromium in the grey mangrove Avicennia marina were measured. Samples were taken from five different sites within the capital city and tested using Flame Atomic Absorption Spectrophotometer (FAAS) for the presence of heavy metals. The total concentrations of selected heavy metals in the mangrove leaves were compared to the general heavy metal concentration for plant. The general heavy metal concentration for plant was based on the heavy metals concentrations measured in the mature leaf tissue of various plant species. The comparison showed that the total concentrations did not exceed the general concentration. Nevertheless, the fact that the leaves which are the least bioaccumulative part of the mangrove warrants further investigation over a longer period of time and sampling from roots and sediments to determine whether heavy metal contamination within the mangrove ecosystem is a possibility.

In the present study, we attempted to find out the biochemical changes in goat eye lens due to Fluoride. Twenty four goat eye lenses were divided into four groups (N=6). Three experimental groups were incubated with three different concentration of Fluoride (50, 100 and 200 ppm) for 24 hours at room temperature. After incubation, lens were homogenised to estimate Lipid peroxide level (LPO), Protein carbonyl content (PC), total protein (TP), GSH and antioxidant enzymes such as SOD and CAT. We observed that gradually, LPO and PC were significantly (p<0.001) increased with the fluoride concentration while reduced glutathione level (GSH) and antioxidant enzymes, superoxidedismutase (SOD) and catalase (CAT) were significantly decreased with the increased concentration of fluoride. On the basis of the results, It may conclude that uptake of excess consumption of Fluoride may be linked with increased oxidative burden which may lead to lens opacification, progression and sometimes leads to development of cataract.

Glyphosate residues in different organs and tissues as lungs, liver, kidney, brain, gut wall and heart of malformed euthanized one-day-old Danish piglets (N= 38) were tested using ELISA. All organs or tissues had glyphosate in different concentrations. The highest concentrations were seen in the lungs (Range 0.4-80 μg/ml) and hearts (Range 0.15-80 μg/ml). The lowest concentrations were detected in muscles (4.4-6.4 μg/g). The detection of such glyphosate concentrations in these malformed piglets could be an allusion to the cause of these congenital anomalies. Further investigations are urgently needed to prove or exclude the role of glyphosate in malformations in piglets and other animals.

The study was aimed at an assessment of the heavy metal distribution in soils, road dust and stream sediments of the city of Ijebu-Ode in order to evaluate the effects of increased urbanization on the quality of the environmental media89 samples comprising 30 topsoil, 54 road dust and 5 stream sediments samples were collected. The samples were air-dried, disaggregated and sieved for the fine fractions (< 75 μm). Portion of the samples were soaked in deionized water for forty-eight hours in the laboratory and the resulting solution was measured for Electrical Conductivity (EC), pH and Total Dissolved Solids (TDS) using standard digital probes. 0.5 g of the fine fractions of each sample was subsequently digested using hoy aqua-regia and analyzed for elemental concentration using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The sieve analysis showed that the soils in the area are silty-sands in nature. The measured pH ranges from (6.1 to 7.6); (6.1-7.6) and (7.0-7.2) for Soil, road dust and stream sediments respectively. The EC ranges from (1-131 μS/cm); (6-27 μS/cm) and (24-387 μS/cm) in soil, stream sediments and in road dust while the TDS ranges from (0.4-89 mg/l); (3-16 mg/l) and (13-248 mg/l) in soils, stream sediments and in road dust. The elemental analysis revealed the following trends for selected metals in soils, sediments and road dusts respectively Cu (9.0-23.0, 12.0-1170 and 7.0-37.0); Pb (11.0-1056, 14.0-679.0 and 16.0-127.0); Zn (15.0-348.0, 86.0-730.0 and 36.0-412.0); Ni (6.0-12, 5.0-21.0 and 4.0-15.0); V(35.0-121.0, 34.0-113.0 and 29.0-135.0), Cr (25.0-94.0, 34.0-213.0 and 36.0-177.0) and As (2.0-11.0, 2.0-22.0 and Below detection limit, bdl-19.0). Further geochemical evaluation of the metals using metal ratio, geo-accumulation index revealed significant concentration of Cu, Pb, Zn, Ni, As and Cr in the environmental media from within the city Centre and along major roads in the city. Extreme metal loads associated with areas of huge vehicular activities, waste dumps and zones with agricultural activities.

The discharge of organic contaminants such as phenol and its derivatives emerging from the industries into water has become a critical concern. In present research, potential of nanoscale iron particle and iron powder has been tested for the removal of 2-chlorophenol from aqueous solutions. In this research, nano particles were procreated by reduction of ferric iron in presence of sodium borohydrid. The characterization of synthesized particles was carried out using SEM and XRD analysis. The effect of pH, initial concentration of chlorophenol, and contact time and sorbents dosage on 2-CP removal was investigated. A statistical experimental design based on “central composite design” was exerted for measure the effect of these variables. The results of the CCD predicted that the maximum adsorption of 2-CP (100%) by nZVI could be achieved at pH, initial concentration, time, and dosage of sorbent as 4, 5.0 mg/L, 70 min, and 1.33 g, respectively. Also, for 86.74% removal of 2-CP, initial concentration, pH, contact time and Fe powder dosage were 5.0 mg/L, 3.23, 56.92 min and 2.50 g respectively.
The results show that the nZVI can be applied for treatment of organic contaminants in water and wastewater. Also, the optimum conditions of these theoretically obtained variables are beneficial for their monitoring which can be applied at an industrial-scale process.

Catla (Catla catla) is one of the most important species of cyprinids in terms of economic and nutritional value that was considered as aquaculture candidate in Khozaestan province (Iran). In this study, 40 female and male Catla broodstocks (imported from India), were studied during year (summer 2011 to spring 2012). Seasonally, blood sampling was collected with heparinated syringe followed by catching and anesthesia. Levels of steroid hormones (testosterone, 17β-estradiol and progesterone) were measured by RIA. Results showed significant differences in all sex steroids during seasonal sampling (P<0.05). High plasma testosterone levels were measured in both sexes (female: 0.13 ± 0.03 ng/ml and male: 0.16 ± 0.04 ng/ml) in the course of the sexual maturation at the end of winter. Highest female plasma levels of 17 β-estradiol (128.50 ± 26.60 ng/ml) was measured in fall. Progesterone also significantly increased at winter (1.32 ± 0.22 ng/ml) in female broodstocks (P<0.05). All broodstocks were ripe and ready to breeding in winter. Water temperature was higth (29.88 ± 1.42) in summer which declined to (14.63 ± 0.47) in winter. According to the results, climatic conditions (Temperature) had a great impact on broodstocks Gonad development via involving of hormones in Khuzestan.