About half of those who have mononucleosis have enlargement of the spleen, usually 2 to 3 weeks after they are infected. The incubation periodâthe time it takes symptoms to appear after a person becomes infected with the virusâcan be 4 to 6 weeks.Symptoms of mononucleosis usually last for 1 to 4 weeks, but it might take as long as 2 months before you feel well enough to resume all of your normal activities.bout half of those who have mononucleosis have enlargement of the spleen, usually 2 to 3 weeks after they are infected. The incubation periodâthe time it takes symptoms to appear after a person becomes infected with the virusâcan be 4 to 6 weeks.
hair analysis. chemical analysis of a hair sample to find possible evidence of exposure to a toxic substance. Molecules of lead compounds and other chemicals are absorbed and stored in hair shafts. Hair analysis is also used to determine possible causes of malnutrition.
This article is about scientific uses of hair analysis. For pseudoscienfic health practice, see Hair analysis (alternative medicine). Hair analysis may refer to the chemical analysis of a hair sample, but can also refer to microscopic analysis or comparison. Chemical hair analysis may be considered for retrospective purposes when blood and urine are no longer expected to contain a particular contaminant, typically three months or less. Its most widely accepted use is in the fields of forensic toxicology and, increasingly, environmental toxicology.