Figure 4.
PCA plots of the GNP sensor array exposed the breath of 59 healthy subjects. Normally, two samples of each subject were analysed. Plots were analysed according to different characteristics: age, gender, place of birth, ethnicity, family cancer history, intake of food additives, drug treatment, work pollution, and smoking habits (see Table 2). The first two principal components depicted contained >90% of the total variance in the data.