Environmental contaminants are chemicals that are present in the environment in which the food is grown, harvested, transported, stored, packaged, processed, and consumed. The physical contact of the food with its environment results in its contamination.Possible sources of contamination include:lso, food contaminant testing assures consumers safety and quality of purchased food products and can prevent foodborne diseases, and chemical, microbiological, or physical food hazards.
The most common cause of portal hypertension is cirrhosis of the liver. Cirrhosis is scarring which accompanies the healing of liver injury caused by hepatitis, alcohol, or other less common causes of liver damage. In cirrhosis, the scar tissue blocks the flow of blood through the liver.
The opposition of blood flow due to friction between the blood and the vessel walls. 3 factors contribute to resistance: 1) The size of the vessel lumen, the smaller the lumen the greater the resistance. Therefore, vasoconstriction increases resistance to flow.