E. Benfenati et al., DIURNAL, WEEKLY AND SEASONAL AIR CONCENTRATIONS OF PCDD AND PCDF IN AN INDUSTRIAL-AREA, Fresenius' journal of analytical chemistry, 348(1-2), 1994, pp. 141-143
Air samples were collected in an industrial area close to Milan in Jul
y and in November, day and night for five days and have been analyzed
for PCDD and PCDF. Average summer levels were generally lower than win
ter levels, and average concentrations were higher by night than by da
y in both months.