Fate and risk evaluation of persistent organic contaminants and related compounds in Victoria Harbour, Hong Kong

The Environment Protection Department of Hong Kong has a monitoring program for persistent organic contaminants in sediments of Victoria Harbour, the main harbour of Hong Kong. A fugacity model has been used, based on this sedimentary data, to estimate inputs to the system (probably from sewage, stormwater and industrial discharges) as well as the fate of the contaminants, particularly in terms of the aqueous and biotic concentrations. The risk of deleterious effects on the natural marine system, as well as on the consumers of seafood from the system, was carried out using the estimated aqueous and biotic concentrations together with accepted environmental quality guidelines. The result of our analysis indicated that the chlorohydrocarbons, PCBs (as Aroclor 1254) total DDT and total HCH pose a significant risk, and probably have caused damage to the marine ecosystem as well as posing a hazard to seafood consumers. Much higher concentrations of the less toxic total alkanes, nonaromatic hydrocarbons, linear alkyl benzenes and the compounds giving a unresolved complex mixture (UCM) cannot be evaluated due to a lack of environmental guidelines and the complexity of these substances. However, it is probable that these substances add adverse effects to those due to the other contaminants.link_to_subscribed_fulltex

Occurrence of persistent organic contaminants and related substances in Hong Kong marine areas: An overview

Data collected between 1987 and 1996 for PCBs and PAHs in marine sediments at 66 stations in 10 water quality zones in Hong Kong were collated and analysed. Statistical analyses indicate that, during 1995 and 1996, the total PCBs and total PAHs were widely distributed in Hong Kong sediments at background concentrations of 5 to 9.8 μg kg -1 and 40 to 60 μg kg -1 wet weight respectively. Elevated levels of total PCBs (up to 25.5 μg kg -1 wet weight) and total PAHs (up to 116 μg kg -1 wet weight) were detected in Victoria Harbour and several other areas. Substantial contamination was found in typhoon shelters (total PCBs, up to 169 μg kg -1 wet weight; total PAHs, up to 1159 μg kg -1 wet weight). Analysis of the data from the 1987 to 1996 time period indicated that total PAHs were declining in most areas, with the estimated half-lives ranging from 2.9 to 10.2 yr.link_to_subscribed_fulltex

Combined Anti-CD40 and Anti-IL-23 Monoclonal Antibody Therapy Effectively Suppresses Tumor Growth and Metastases

Fulltext embargoed for: 12 months post date of publicationTumor-induced immunosuppression remains one of the major obstacles to many potentially effective cancer therapies and vaccines. Host interleukin (IL)-23 suppresses the immune response during tumor initiation, growth, and metastases, and neutralization of IL-23 causes IL-12-dependent antitumor effects. Here, we report that combining agonistic anti-CD40 monoclonal antibodies (mAb) to drive IL-12 production and anti-IL-23 mAbs to counter the tumor promoting effects of IL-23 has greater antitumor activity than either agent alone. This increased antitumor efficacy was observed in several experimental and spontaneous lung metastases models as well as in models of de novo carcinogenesis. The combination effects were dependent on host IL-12, perforin, IFN-γ, natural killer, and/or T cells and independent of host B cells and IFN-αβ sensitivity. Interestingly, in the experimental lung metastases tumor models, we observed that intracellular IL-23 production was specifically restricted to MHC-II(hi)CD11c(+)CD11b(+) cells. Furthermore, an increase in proportion of these IL-23-producing cells was detected only in tumor models where IL-23 neutralization was therapeutic. Overall, these data suggest the clinical potential of using anti-CD40 (push) and anti-IL-23 mAbs (pull) to tip the IL-12/23 balance in established tumors