Cadmium distribution and mobility in river nile

Question 1

cadmium sources

Answer 1

natural: volcanism,weathering of rocks and forest fires
anthropogenic: cement manufacturing, mining,smelting, coal combustion

Question 2

cadmium in the environment

Answer 2

cd does not break down–> it changes forms
- cd binds strongly to soil particles
- animals plants take up cd

Question 3

Enrichment factor

Answer 3

minimum factor by which theweight percent of mineral in an orebody is greater than the average occurence of that mineral in the earths crust

• EF= (Ci/Cr)/(Bi/Br)
  where Ci and Cr are concentrations of the metal and the reference metal in the sample (Al), which Bi and Br are the background concentrations of the metal and the reference)

EF< 2 indicates no or minimal enrichment
EF bw 2 and 5 indicates moderate enrichment
Ef bw 5 and 20 indicates significant enrichment
EF bw 20 and 40 indicates very high enrichment
EF> 40 indicates extreme enrichment

Question 4

Contamination Factor

Answer 4

Represents level of contamination:
CF=Cmetal/Cbackground
where Cmetal is the metal concentration, and Cbackground is the background value of Upper continental crust

CF<1=low contamination
CF= (1-3) moderate
CF=(3-6) considerable
CF>6= very high

Question 5

Geo-accumulation index

Answer 5

Measures extent of anthropogenic pollution, geochemical background value, and natural diagenesis enrichment

Igeo < 0 unpolluted,
Igeo (0–1) unpolluted to moderately Igeo (1–2),
moderately polluted Igeo (2–3),
moderately to heavy polluted Igeo (3–4),
heavy polluted Igeo (4–5),
heavy to extreme polluted and
Igeo > 5, is extremely polluted.

Question 6

Ecological Risk Index

Answer 6

assesses the potential risk to the ecology of one or more constituents
Er = Cif ∗ Tri
where Cif is the contamination factor, Tri is the toxicity response coefficient of each element (Cd = 30) and Er is the ecological risk factor of each element.
Er values were categorized as follows:
Er <40 is low pollution
40 < Er < 80 moderate potential risk
80 < Er < 160 high potential risk
160 < Er < 320 very high potential risk
Er > 320 dangerous.

Question 7

impacts on nile

Answer 7

• Cadmium concentration differences along the river with average from Aswan to Cairo is (0.16 mg kg−1) and is recorded high concentration and pollution degree near the water treatment plant and brick factory of Beni Suef, the iron and steel factory of Helwan, the oil and detergent factory of Sohag, and discharge of cement factory in Samalut (Table 1).

-Due to the increase in population growth, urbanization, and industrialization along the river, the Cd was higher than in previous studies conducted on Egypt’s Nile River. Corresponding to the risk assessment code, Cd is high risk at Luxor, Beni Suef, Nasser, BniMazar, and Aswan.

-Also, water cadmium concentrations are higher than permissible limits in Cairo, Giza, Helwan, Beni Suef, Sohag, Qena, and Samalut (Table 5).

-Cluster analysis reveals three pollution sources: agriculture discharge, industrial activities, and (domestic and sewage sludge). The Cd concentration is significant at Beni Suef, Aswan, Helwan, Samalut, and Sohag in sediments and water with high bioavailability and mobility related to the vicinity of anthropogenic sources (Figure 5).

Heavy metal pollution endangers the Nile River since it serves as an Irrigation and freshwater source for the cities and farms that line its banks.

-Cd pollutes the environment and is toxic at low concentrations.

The pollution level of cadmium in sediments is moderate to high at all sample stations along the river. The concentration and distribution of Cd in rivers are affected by the vicinity of anthropogenic sources such as household waste, sewage sludge, agricultural runoff, and industrial activity

Question 8

How are people exposed to cadmium?

Answer 8

Smoking cigarettes or breathing cigarette smoke.

Eating foods containing cadmium; low levels are found in all foods (foods that usually contain more cadmium include shellfish, liver, and kidney meats).

-Breathing contaminated air in certain workplaces (e.g. battery manufacturing, metal soldering, welding, metal smelting).

Drinking contaminated water.

Living near an industrial facility that releases cadmium into the air.

Burning of fossil fuels.