Toxicología ambiental y analítica

Studies on acute toxicity of textile effluents, collected from various Textile Dye Industries from Erode industrial area, Tamil Nadu, have been carried out. The juveniles of pink prawns (Metapanaeus monoceros) were exposed to a mixture of effluent samples in five different concentrations prepared in seawater, using static acute toxicity test protocol to obtain the 96-h LC50. The five different dilution factors of effluents made up with seawater were 200, 100, 50, 33.33, and 20 respectively. The environmental factors such as salinity, temperature, dissolved oxygen and pH were monitored from different effluent dilutions every 24 hours during the experiment till 96 hours. Each tank of different effluent dilution contained 10 test organisms in 3L of effluent content besides a control tank. The results showed that the 96-h LC50 of Erode effluent samples for prawns is 29 ppm, the upper limit is 41 ppm and the lower limit is 17 ppm. Maximum mortalities occurred at a dilution factor 20 i.e. concentration of 50 ppm. This indicated a greater toxicity of these tested textile effluents from Erode (with a Dilution Factor of 20) as compared to the effluents tested earlier by other workers from different dye industries in Erode area (with a Dilution Factor of 5).

Pregnant anaemic patients of Sargodha region were asked to take oral iron supplementation (150 mg per day) in the form of available medicines up to the period of two months. Blood samples were collected before the initiation of treatment and secondly after the two months of treatment. Evaluation of serum minerals shows that, iron level increases from 65 μg/dl-75 μg/dl in Group-1 and 62 μg/dl-78 μg/dl in Group-2 before and after supplementation respectively this increase is statistically significant (p=0.000). Results shows that iron supplementations have no effect on serum calcium. So values of serum calcium remain same after two months in both groups. Change in P values are statistically insignificant (P>0.05). The mean values of serum calcium remains same in Group-1 is 8.9-9.1 mg/dl (p=0.07), SD=0.66-0.7 and in Group-2 it is 9.0-9.1 mg/dl (p=0.83), SD=0.6-0.7 before and after supplementation respectively and values of serum copper decreases in both groups. Change in P values are statistically insignificant (P>0.05). The mean values of serum Cu in Group-1 is 108-107 μg/dl (p=0.35), SD=28.3-28.0 and in Group-2 it is 110-109 μg/dl (p=0.13), SD=24.4-23.0 before and after supplementation respectively. Serum zinc values significantlydecrease (p=0.00) from 68 μg/dl - 66 μg/dl and 68 μg/dl - 67 μg/dl in Group-1 and Group-2 respectively. It may be dueto positive effect on serum iron level and negative effect on serum zinc status. Serum calcium and copper remainsunaffected from iron supplementation. The variations were almost similar in both age groups (1 & 2) means effects of iron supplementations are similar irrespective of the age of pregnant anaemic patients, the only noticeable change was that variations are comparatively fast in Group-1 as compare to Group-2 it may because of greater absorption of nutrients in young ones than that of aged subjects.

"Heavy metals" which have specific gravity about 5 times that of water were determined in the different effluent samples taken from Selaqui industrial area. When water is contaminated with heavy metals then water becomes toxic and dangerous for our biological system. Quality of water affects our biological system and our surrounding is also affected. In the present study concentrations of some heavy metals in the effluents of pharmaceutical Industries operating in the industrial area (Selaqui region) of Dehradun were determined using atomic absorption spectrophotometer. The heavy metals analyzed in this study included Cadmium, Chromium, Lead, Nickel, Zinc and Copper. Most of the samples were found to contain the metals in varying concentrations. The highest concentration of heavy metal detected was Iron with concentration of 10.80 mg/L. The highest concentration for Pb was found to be 0.26 mg/L while 0.55 mg/l for Cd.Zinc was obtained in the range of 1 to 1.3 mg/L, Copper in the range of 0.08 to 0.38 mg/L and Nickel 0.03 to 0.12 mg/l. Chromium, lead, cadmium and nickel were found to be above the permissible limit recommended by WHO standards. Different metals were found within the permissible limit in ground water sample but if these effluents containing above mentioned heavy metals are drained regularly without proper treatment, then after some years the ground water will not be suitable for drinking purpose and it may cause diseases in the human being and animals and will also affect the flora of the region. This study reveals the need for enforcing adequate effluent treatment methods before their discharge to surface water to reduce their potential environmental hazards.

Ground water samples from four drilled wells with different depths were collected in May 2011 from Southwestern Sinai to study the distribution of radionuclides and their hazards effect. The depths are ranging between 30 and 150 m. The collected water has very low salinity as the total dissolved salt (TDS) is ranging between 1226 and 1836 ppm. The chemistry is mainly chloride as the anions distribution are in the order Cl- > SO42-> HCO3-> CO32- and the cations are in the order Na+ > Ca+2> K+> Mg+2. Results shown that the correlation coefficient between Na+ and Cl- was strongly positive (0.99), while it was 0.82 between Ca2+ and SO4 2-. The activity concentration of 238U is ranging between 8.2 and 14.0 Bq/L and it is slightly correlated with Mg+. 232Th activity concentration is very low and ranges between 0.316 and 0.683 Bq/L, while 40K ranges between 0.868 and 2.3 Bq/L. The activity concentrations of 222Rn are ranging between 540.5 and 1163.3 Bq/L and its progenies (214Pb, 214Bi) did not reflect its concentration. Radon exhalation rate was calculated using a-track detector. The annual effective dose was calculated for the different personal ages. The babies (< one year) are the most annually dosed.

In this study, the levels of organochlorine (gamma-BCH, Alpha-BCH, aldrin, o,p’-DDE, endosulfan, dieldrin, p,p’-DDT, lindane, p,p’-DDD, o,p’-DDD and methoxychlor) pesticide residues in Alau Dam from Konduga Local Government, Borno State, Nigeria, was investigated using fish samples as a case study. Four fish species (Clarias gariepinus, Heterotis niloticus, Oreochromis niloticus and Tilapia zilli) were collected for this analysis. Fish samples of uniform size were collected in order to avoid possible error due to size differences. The fish samples were labeled with a unique identification number. Samples of fishes were transported to the laboratory on the same day and later dissected to remove the flesh, liver, stomach and Gills of each species of fish and store using 4% formalin pending extraction and analysis. The extraction, clean up and de-fattening of the fishes organs were carried out using standard procedures. The levels of all the pesticide residues were determined using GC/MS SHIMADZU (GC – 17A) equipped with electron capture detector (ECD). Eleven organochlorine pesticides were detected in all the fish samples studied. Endosulfan was the most abundant pesticide residue in the studied tissues of all the fish species with a value of 8.98 ± 0.02 μg/g in the liver of Oreochromis niloticus. This study also revealed that, all the pesticide residues in the fish samples studied were above the maximum residues limits (MRLs) and dietary intake (ADI) and could be an important process of transferring pesticides to humans. It also indicated the extensive presence and usage of these pesticides in the study environment, which include recent use of this pesticide for agricultural purposes. Thus, the use of these pesticides to control pest by farmers within the study area with little or no knowledge must be checked through adequate control of the trade and use of pesticides and the enforcement of appropriate sanctions.