The current study was conducted on the valley of Duhok and the agricultural lands irrigated from it, where three sites were identified for collecting samples quarterly from soil and sediment using clean plastic bags for the purpose of measuring lead, nickel, cobalt and copper. Pollution load index (PLI), Nemerow pollution index (PIN), Potential Ecological Risk (PER) and Geo-accumulation Index (Igeo) were also calculated according to the internationally approved methods. The results indicated that most of lead, nickel and copper concentrations in soils and sediments exceeded the limits allowed by WHO, reaching annual rates (96.758, 168.746 and 29.88) , (111.25, 219.65 and 48.162) mg.kg-1, respectively. This fluctuation in concentrations was reflected in the values of the studied indicators for both soil and sediment, where 50% and 58% of the studied specimen are of the polluted grade and the remnant are of the non-polluted grade according to the PLI values. So is the case with PIN where 58% of the soil specimen and 41.6% of the sediment samples were of the severe pollution grade, while 25% and 33.3% of the specimen were of the heavy pollution grade and the remnant were slightly pollution grade. The same applies to the results of the PER index values, where 50% and 41.67% of the specimen were from the Medium ecological risk category, and the rest were from the low ecological risk category, likewise for the (Igeo) values, 100% and 96% of the soil and sediment samples were from the Weakly polluted category.

The current study was conducted to assess the water quality of Valley Duhok as a water source for drinking livestock and poultry in the region. Seventy-two water samples were collected from six sites in the valley to conduct physicochemical and biological tests, and the sub-index model (WQI) was applied to assess water quality.The results of the water quality index indicated that the water of Duhok Dam Lake (site N1) was of good quality for drinking livestock and poultry, while the rest of the sites on the valley were in the category of water very poor for drinking animals, with WQI values ​​ranging from (204-286).This deterioration in water quality is a result of the relative increase in the three parameters of most of the studied properties, especially dissolved oxygen, organic load, and phosphate ions, to reach the values ​​for the quality rating (Qi) and Sub-Index (Sbi)to(500and56.8),(1026and117)and(958and87.1)consecutively.

A field survey was conducted for Duhok valley, fields and orchards in northern Iraq, where water is usedfor irrigation. Six sites were identified for collecting water samples starting from February 2021 untilJanuary 2022 to estimate both (pH, Electrical conductivity (EC25), chloride ions (Cl-), bicarbonate (HCO3-) as well as irrigation parameters such as sodium adsorption ratio (SAR), residual sodium carbonate (RSC),sodium percentage (% Na), permeability index (P.I), kelly ratio (K.R), Magnesium hazard (M.H) andpotential salinity (P.S). The pollution index (PIJ) model was used to assess water quality for irrigation.The results of the current study indicated that the water quality index (PIj) values ranged between (0.9691to 1.4559) and that 66.7% of the water samples were from the Lightly polluted water category, and therest were from the good quality category for irrigation purposes. The relative deterioration of most of theirrigation water samples is attributed to the high concentration of bicarbonate ions (HCO3-) and themagnesium hazard (M.H), which reached (7.80) meq. l-1 and (84.0), respectivel (14) (PDF) Water quality assessment using the pollution index model (PIj) for irrigation purposes. A case study: Dohuk valley water in northern Iraq.. Available from: https://www.researchgate.net/publication/361924460_Water_quality_assessment_using_the_pollution_index_model_PIj_for_irrigation_purposes_A_case_study_Dohuk_valley_water_in_northern_Iraq [accessed Aug 10 2022].

The water quality of the Duhok Valley stream was studied as one of the sources of pollution for the water of Mosul Dam Lake, which is located on the Tigris river.The necessary environmental tests were conducted for the water samples taken from different locations in the valley to investigate the degree of pollution of its water using the water quality index (WQI), and the extent of the impact of self-purification processes in improving the water quality before it reaches the dam lake.The results indicated that the water quality of Duhok Dam site (S1) was of medium water quality, while the rest sites of the valley were of poor quality, as the water quality index ranged between (26.8 to 39.4) and this deterioration in quality is due to the huge amount of the wastewater drained into it, which led to an increase in the organic load, phosphate and EC25 to reach (66.0, 25.0) ppm and (1135) µs.cm-1, with a lack of dissolved oxygen in the water in some locations and for some periods, and no noticeable improvement was observed in the water of the valley before it reached the Mosul Dam lake except for dissolved oxygen, sulfate and chloride ions.

Drinking water samples were taken from 18 villages around Zakho district, Kurdistan region, Iraq in annual seasons of 2018 year and chemical analysis of most important water quality parameters were carried out. Water temperature is varied about 13.2◦C to 18.7◦C, four villages have slight acidic water while other 15 locations are tend to be slight alkaline and highest pH value reaches 8.4, electrical conductivity (µs/cm) is over the permissible values of standard drinking water in two villages and high in 4 location while normal in the rest 13 locations, statistical analysis of dissolved oxygen ranges between 6.73 - 8.40 mg/l, statistical analysis of total hardness revealed that the all villages around Zakho district have hard to intensive hard water over 500 mg/l and gives them a slight bitter taste, calcium hardness gives extremely ranges between 72-392 mg/l, and Mg hardness between 39-250 mg/l, statistical analysis of chloride shows is around 250 mg/l which is typical standard for drinking water, SO4 is low and their means located between 18-58 mg/l and NO3 not exceeded 5 mg/l along year months reflecting their purity from pollution. The content of heavy metals Cd, Cu, Mn, Zn, Fe, Ag, Ni, Cr ,Co, are below maximum permissible WHO guidelines and save for drinking while lead is over WHO permissible levels in this rank Mala> Jajoe >Easlam> Bntate> Banee villages and considered a dangerous indicators for drinking water quality in these villages.

In this study, lasted for six months from October 2016 to April 2017 in the Akra district of Duhok governorate, we found out the validity of the spring water of the area to be used as drinking water. Indeed, the aim of this study was to assess the validity of the water of spring of the Akra area for human consumption as potable water. The results showed us after the analysis and laboratory examinations (i.e., electrical conductivity (EC), total alkalinity (TA), total dissolved solids (TDS), pH, total hardness (TH), magnesium (Mg 2+ ), Calcium (Ca 2+ ), Dissolved oxygen (DO), and Chloride (CL - )) of all springs water of the region in terms of physical and chemical properties are safe to drink and can be identified as a good source of human consumption. Although there is a difference in some physical and chemical properties in some springs of water in that area, it did not exceed the limits and international standards for drinking water. Therefore, the people of this region can use the water of those springs to drink without fear of any health effects.

This study evaluates the physical and chemical characteristics of well water in Zakho district, Duhok governorate. Standard field and laboratory methods were followed. In order to characterize ground water quality in Zakho district, eight wells were selected to represent their water quality. Monthly samples were collected from the wells for the period from October 2016 to April 2017. The samples were tested for electrical conductivity (EC), total alkalinity (TA), total dissolved solids (TDS), pH, Nitrate (NO3-), total hardness (TH) and chlorides, according to the standard methods (American Public Health Association. The results of statistical analysis showed significant difference among the wells water quality in the measured parameters. Ground water of Zakho district have high dissolved ions due to the dissolved rocks of the study area. Total dissolved solids of more than 1000 mg/l made the wells Frawla, Kealk and Zarek need to be treated to made taste palatable. Additionally high electrical conductivity and TDS made Zakho ground water have a slight to moderate restriction to crop growth. The high alkalinity of Zakho ground water indicated stabilized PH . The water quality of all the wells were found excessively hard. The nitrate concentration of Zakho well water ranged between 0.19 to 42.4 mg/l below the guidelines for.

This study describes the evaluation case of medical waste management in the largest hospital in terms of the number of sections and the number of patients and visitors to Shaabaniya and Bidar Hospital in Zakho city, Iraq's Kurdistan region. Found through this study the number of the patients referred to hospital for the various tests of males and females in different ages is about (706958 patients) and the number of the patients who remained is about (32926) which lasted for two years as of (15/06/201530/05/2017). The number of varies surgical operation in the hospital of Shaabaniya is about 12801 operation during the same years (2015-2017), this leads to increases the amount of hazardous medical waste that was reported at the above mentioned clinics 27250 Kg and 5711 Kg, respectively. The aim of this study is to activation the role of medical waste in the separation, collection, storage, transport, and treatment of these wastes. And reduce the rate of medical waste generation, both in terms of quantity and quality, by developing the technology used, adopting clean technology, and selecting substitutes or primary materials that are less invasive of the environment and public health. But the result of study show the existence of administrative practices of improper disposal of medical waste in terms of the separation of hazardous and non-medical waste operations and this is due to the negligence and carelessness in the instructions issued by the authorities of administrative supervising the application of the collection, separation, transport and storage of the waste temporarily inside hospital pending transfer to operations final treatment with municipal waste. In addition to the lack of environmental awareness among workers in the field of hygiene and lack of provision of required equipment for personal protection and the lack of a program or plans to train workers in hygiene and how to deal with the medical waste and Prevention, note that the continuous production of waste per day throughout the year, so it is necessary to work hard to improve the administration consistently and effectively and to work hard to provide the infrastructure necessary for the success of the administrative process required.