Evidence of PCDD/Fs and PCBs contamination in trees grown in forests far from their production and contamination-free areas.

Polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in trees grown in pathless forests were analyzed to investigate their dispersal patterns in the atmosphere. The pg/g levels of 23 PCCD, 22 PCDF, and 54 PCB congeners were identified. The total amount of PCDDs in the red pine tree sample (95.8 pg/g) was approximately 7 times that in the beech tree sample (13.2 pg/g). The total amount of PCDFs in the red pine tree sample (71.1 pg/g) was also approximately 7 times that in the beech tree sample (11.1 pg/g). The total amounts of PCBs in the red pine tree and beech tree samples were 1,380 and 1,150 pg/g, respectively. The (Cl1-Cl3)-PCBs comprised 63.1 % and 67.6 % of total PCBs in the red pine and in the beech, respectively. The results of the present study indicate that PCDD/Fs and PCBs are transferred over long distances in the atmosphere and accumulated in the contamination-free areas.

Formation of dioxins during the combustion of newspapers in the presence of sodium chloride and poly(vinyl chloride).

Exhaust gases from the combustion of newspaper alone, from branches of London plane tree alone, and from newspapers mixed with sodium chloride (NaCl), polyethylene, or poly(vinyl chloride) (PVC) were collected. The samples were analyzed for dioxins by gas chromatography/mass spectrometry. Total amounts of dioxins found in the samples were 0.186 ng/g from newspapers alone, 1.42 ng/g from the branches of London plane, 102 ng/g from newspapers impregnated with sodium chloride (CI wt % = 3.1), 101 ng/g from newspapers impregnated with sodium chloride mixed with PVC (Cl wt % = 2.6), and 146 ng/g from newspapers mixed with PVC (Cl wt % = 5.1). Samples with a higher chloride content produced more dioxins, and there is a clear correlation between dioxin formation and chloride content. The amount of dioxins formed in the samples according to the number of chlorides was Cl5 > Cl4 > Cl6 > Cl7 > Cl8 in PCDD isomers and Cl4 > Cl5 > Cl6 > Cl7 > Cl8 in PCDF isomers, except in the case of newspapers alone. Benzofurans composed 78-92% of the total dioxins formed in the exhaust gases. The higher the number of the chlorides, the lower the production of benzofuran observed. NaCl vaporized at the temperature of the flame used for combustion of the samples (760-1080 degrees C). The results indicate that NaCl and PVC contribute significantly to dioxin formation from waste materials combusted in incinerators.

Migration of organophosphorus insecticides cyanophos and prothiofos residues from impregnated paper bags to Japanese apple-pears (Pyrus pyrifolia nakai cv. Nijisseiki).

Bags impregnated with the organophosphorus pesticides prothiofos and cyanophos in three levels were used to cover Japanese apple-pears to protect them from insects. The amounts of prothiofos residue in the bags collected 4 months after application ranged from 0 to 34% of the amounts (81, 148, and 333 microg) found in the bags prior to a bagging. The amounts of cyanophos residue in bags collected 4 months after application ranged from 11 to 29% of the amounts (335, 2860, and 3740 microg) present prior to a bagging. Amounts of prothiofos found in fruits after 4 months ranged from 0 to 0.076 ppm. Amounts of cyanophos found in fruits after 4 months ranged from 0 to 0.011 ppm. Results of the present study indicate that these two pesticides migrated from pesticide-impregnated bags to fruits during the growing season.