| The current era is witnessing great industrial revolutions,coupled with a linear and continuous increase in the use of different chemicals including pharmaceutical drugs,heavy metals,fertilizers,and pesticides.Exposure to these chemicals is linked with a number of different disorders,diseases,and toxicological endpoints in humans and other non-target organisms.The current work was aimed at evaluating the hostile effects of pollution on humans and animals(using fish as a model animal).The toxic effects of pollution on humans were studied through questionnaires as well as lab-based investigation.However,to know the in-depth mechanism of toxicity of pollution,fish were employed as a model organism.The hostile effects of pesticides and heavy metals on fish were studied,both in vivo and in situ respectively.To broaden the ideal toxicity markers in vivo,two different fish species were employed in the studies against two different insecticides in the lab.However,the in situ based studies provided a broader impact of heavy metals pollution on account of involving a mixture of heavy metals in the real world environment.Having both humans and fish-based studies,the thesis was broadly categorized into two parts.The first part consisted of human-based studies whereas the second part consisted of fish-based studies.The first part reported air pollution associated hostile effects on students,the effect of air pollution on the performance of marathon racers,and pesticides-based air pollution-mediated adverse effects on occupationally exposed farmers.The final part reported pesticides and heavy metals induced toxicities in different fish species.An online questionnaire was administered to 4021 students from Northern division of Pakistan to investigate the self-reported effects of air pollution on them.The questionnaire was having four sections;the first section was focused on the physical effects associated with air pollution;the second section was focused on air pollution linked behavior and psychology;the third portion was focused on perception and awareness of the subjects;whereas the final section was focused on practices and concerns of the subjects regarding air pollution.The students reported that exposure to air pollution significantly affected their physical health,behavior,and psychology.The subjects were aware of different air pollutants,health complications associated with air pollution,and therefore had adopted preventive measures.It was concluded that air pollution had adverse impacts on the physical and psychological health of the respondents,which consequently altered their behavior.Mass awareness,proper mitigating future plan,suitable management,and implementation of strict environmental laws are suggested before the air gets further polluted and becomes life-threatening.Air pollution has been linked with a number of health risks and complications of the respiratory system.The longer the duration of the exposure,the more severe the cumulative harmful effects.However,research regarding the short-term impact of air pollution on athletes is still scanty,more specifically the effect of air pollution on the performance of marathon racers.Therefore,this study was aimed to assess the possible influence of air pollutants on the performance of marathon runners in China.After filtering the data,a total of 266 marathon runners(132 females and 134 males),who took part in at least five races were included in the dataset.The data was analyzed through linear mixed effects models in R.The influence of air quality index,particulate matters(PM2.5 and PM10),SO2,NO2,CO,and O3 were examined on the performance of the marathoners.Environmental factors including elevation,temperature,and speed of the wind were also taken into consideration.It was concluded that male racers spent less time to finish the race.An age-dependent linear increase was observed in the finishing time.The performance of the male marathon racers was affected by SO2 and O3 only,however,the performance of the female racers were affected by SO2,O3,PM10,and PM2.5.The male racers were more affected by the increase in SO2 from the first quartile to the fourth as compared to female racers;whereas,the female racers were more affected by the increase in O3 from the first quartile to the fourth as compared to male racers.The comparisons of the models revealed that the SO2 model was the best fit model for both males and females,followed by O3 model.The use,knowledge,risk perceptions,and adverse impacts of pesticides based air-pollution on the occupationally exposed farmers were studied.The study consisted of two parts.The first part consisted of a questionnaire-based study to evaluate the use,diversity,and risk perceptions of pesticides among the farmers.The second part assessed the effects of pesticides exposure on farmers.For the first part,a comprehensive questionnaire was administered to 285 farmers of different age groups and farming experience.The questionnaire appraised their sources of information and decision-making regarding pesticide use,pest control strategies,diversity of pesticides used in higher concentrations,health complications during or after spraying pesticides,and pesticides risk perceptions.On the basis of the perceived risks,pesticides risk perception score was calculated.For the second part,blood samples from 120(60 farmers and 60 control)volunteers were collected.The effects of pesticides on the hematology(red blood cells,hemoglobin,hematocrit,platelets,mean corpuscular volume,mean corpuscular hemoglobin,leucocyte,neutrophils,lymphocytes,monocytes,eosinophils,and basophils),oxidative stress level(malondialdehyde),blood biochemistry(glucose,cholesterol,triglycerides,and creatinine),enzymatic profile(acetylcholine esterase,butyrylcholinesterase,reduced glutathione,glutathione peroxidase,glutathione-s-transferase,and superoxide dismutase),liver function(alanine aminotransferase,aspartate aminotransferase,alkaline phosphatase,and ?-glutamyl transferase),and sex-hormones(follicle stimulating hormone,luteinizing hormone,and testosterone)were assessed.Subtle biochemical and hematological effects of pesticides were observed.It is recommended that the behavior of the farmers regarding pesticides use should be modified through training and awareness about integrated pest management,pest control through non-synthetic methods,appropriate use of pesticides,and health hazards associated with the overuse or misuses of pesticides.The first portion of the studies on fish consisted of investigating pesticides arbitrated hostile effects on fish.However,this portion employed two pesticides,so the first sub-portion appraised multiple-biomarkers based toxicity of deltamethrin on Hypophthalmichthys molitrix(silver carp).The second sub-portion evaluated malathion induced oxidative stress leading to hematological,histopathological,and biochemical toxicities in Labeo rohita(rohu).Preliminary,the acute concentrations of the pesticides were investigated and secondarily the fish were exposed to their acute concentrations.Exposure to the acute concentrations of deltamethrin and malathion induced severe and deleterious toxicities in the exposed fish species.The exposure led to different behavioral inconsistencies and biochemical(DNA,protein,glucose,enzymes,hormones,etc.),hematological(RBCs,WBCs,Hb,etc.),and histopathological toxicities in the liver,gills,muscles,and brain of silver carp and rohu.Disturbed serum biochemistry(albumin,cholesterol,total bilirubin,urea,etc.)was also obvious.The induction of the changes and damage clearly demonstrated the mechanism of toxicities of the pesticides in vivo.The current studies provided significant information for devising better strategies regarding environmental management,biodiversity conservation,and monitoring of aquatic organisms.The results clearly classified the employed pesticides as severely toxic to the studied fish species.Therefore,it is recommended that their extensive use should be prohibited or allowed under strict environmental laws;otherwise,these might lead to the extermination of the susceptible wildlife including commercially important fish species,such as silver carp and rohu.The construction of hydropower projects discharges effluents to aquatic bodies such as rivers.The effluents consist of different chemicals or pollutants such as heavy metals.The final portion on the fish-based studies evaluated the availability of heavy metals in the sediments and water of the river Panjkora,currently under use for construction of Koto hydro-electric power project.The bioaccumulation of heavy metals in the tissues of different fish species including Cyprinus carpio,Crossocheilus diplocheilus,Racoma labiata,Schizothorax plagiostomus,Schizothorax esocinus,and Tor putitora was also determined.The effluents from the project increased heavy metals bioaccumulation in the tissues of the studied fish species.However,the fish biodiversity of the river was observed to be alarmingly decreased as compared to previous studies on the river.As compared to these studies on the river,a total of ten fish species went missing and a number of high game prized species were observed to be on decline swiftly.Keeping in view the current study and deleterious effects of the poorly-managed or under-construction hydro-power projects(on the water quality of the river,fish diversity,and bioaccumulation of heavy metals at a threatening rate in the tissues of the highly prized game fish),it is recommended that the governmental,local,and provincial funding bodies or organizations should impose developers to comply with the international state-of-the-art environment&safety rules;similar to the rules of the international financial institutions(i.e.,world bank,AFB,etc.),even if no such international funds are directly attached to the project.Furthermore,the hydraulic stress(thermal and hydro-peaking)after completion of the projects should be planned in a proper way to avoid further biodiversity loss.The toxic effects of the heavy metals were also studied on the critically endangered and national fish of Pakistan,Tor putitora,collected from the river Panjkora.Different biochemical changes were observed in the tissues of T.putitora including stress biomarkers(reactive oxygen species and lipid peroxidation),total protein contents,antioxidant enzymes(catalase,superoxide dismutase,peroxidase,reduced glutathione,glutathione reductase,and glutathione-s-transferase),the activity of acetylcholinesterase,and whole body cortisol.Hematotoxic effects were also observed as the count of red blood cells,hematocrit,and hemoglobin decreased,whereas the count of white blood cells increased.Serum biochemical analysis revealed that cholesterol,urea,total bilirubin,and glucose concentration increased,whereas total proteins and albumin decreased with an increase in the concentration of heavy metals across the sampling sites.The fish from the river was found to be under severe stress as compared to the fish from the reference site.The toxic effects observed in the current study provided an insight into the missing or declining number of the fish species in the river as a result of effluents from the project.To mitigate the current scenario,it is suggested that the fisheries departments or organizations should stock fish in an appropriate amount,and should assess fish diversity and water quality at regular intervals to avoid further deterioration and diversity loss.The wildlife departments or organizations should ensure the safety and conservation of wild fauna at any cost.Strict environmental protection and fishing laws should be implemented. |
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