Annex 1 to the Interim Report
Potential for long-range transport
Download 172.3 Kb.
|
- Navigate this page:
- Consequences
- Toxicity
Potential for long-range transportThe vapour pressure of -endosulfan is 1.9 x 10-3 Pa, of -endosulfan 9.2 x 10-5 Pa (1). The value of Henry's Law Constant indicates a potential for volatilisation from moist surfaces, being 1.1 Pa x m3 x mol-1 for -endosulfan and 0.2 Pa x m3 x mol-1 for -endosulfan (2). Studies on leaf surfaces and soil also show a high loss rate to the atmosphere, and a higher loss of - than of -endosulfan (2). The half-life in air has been calculated to 8.5-27 days (2). Endosulfan has been detected in samples of Arctic air (1,2) and Arctic sea water (1). Reported mean concentrations in Arctic air are 3.0-8.3 pg/m3 (1). From this information, the criterion for long-range transport is considered to be met. In European rivers, the - and -isomers as well as the breakdown product endosulfan sulfate been detected (1). The concentrations are low but considering the high toxicity to aquatic organisms they are not negligible. In addition, the presence in river water points to a route of transport from the areas of use to, e.g., sea water. Endosulfan is included in The list of priority substances in the field of water policy, established under Directive 2000/60/EC of the European Parliament and of the Council, establishing a framework for Community action in the field of water policy (3). In the context of the Water Framework Directive, the following mean concentrations have been reported for European surface waters (4):
For the sediment phase, the following mean concentrations were reported (4):
ConsequencesThe reported reduction of European consumption, mainly achieved in northern countries (see above), points to a possibility to reduce the usage also globally without too severe impacts on agriculture, horticulture and forestry. However, it is most likely that countries suffering from a higher insect pest pressure would encounter significantly larger difficulties. In comparison with potential chemical substitutes for endosulfan, it is important to consider also that target organisms are less likely to develop resistance against endosulfan, and also that endosulfan show lower toxicity to beneficial insects than some of the alternatives (1). Within the work under the OSPAR Convention, endosulfan has been included in the List of Chemicals for Priority Action under the OSPAR Strategy with regard to Hazardous Substances, with the ultimate aim to achieve concentrations in the marine environment close to zero. References
Methoxychlor 1,1,1-trichloro-2,2-bis(4-methoxyphenyl)ethane CAS No. 72-43-5
The degradation of methoxychlor is slow during aerobic conditions but much faster during anaerobic conditions. The half-life has been measured to < 30 days for anaerobic degradation in sediment and > 100 days during aerobic degradation in sediment. This degradation pattern is the same in soil. The half-life has been measured to 46 days, which indicate that methoxychlor is less persistent than DDT. The degradation products of methoxychlor are suspected to be endocrine disruptors (7). It is unclear if methoxychlor meets the criterion for persistency. Bioaccumulation Log Kow is 4.7 – 5.1. Bioconcentration factors (BCFs) in three different fish species are (1): 113-264 (sheepshead minnow), 1 500 (western mosquito fish, test duration only 72 hours), and 8 300 (fathead minnow, flow-through system). Methoxychlor seems to meet the criterion for bioaccumulation. ToxicityMethoxychlor is extremely toxic to aquatic organisms. The acute toxicity (LC50) for fish is 52 µg/l and 67 µg/l for rainbow trout and bluegill sunfish, respectively. The acute toxicity (LC50) for daphnids is as low as 0.8 µg/l. Methoxychlor is an endocrine disrupting chemical (2). The criterion for adverse effects is considered to be met. Potential for long-range transport Methoxychlor has a low vapour pressure (1.9 x 10-4 Pa) but Henry's Law Constant is 1.6 Pa x m3 x mol-1 which indicates a potential for volatilisation. The half-life in air is reported to be only 4 to 6.8 hours, which does not meet the criterion for long-range transport. However, methoxychlor has been detected in rain and snow from remote areas in Canada, which indicate that methoxychlor may be persistent in the atmosphere and undergo long-range transport. (4) Directory: fileadmin -> DAM -> env DAM -> United Nations st/SG/AC. 10/C. 3/2016/42 DAM -> United nations e DAM -> United Nations ece/trans/2016/33 DAM -> United Nations ece/trans/WP. 15/AC. 1/2014/13 DAM -> Technical Report on the development of a World-wide Worldwide harmonised Light duty driving Test Procedure (wltp) DAM -> WP. 29-153-32 (153rd wp. 29, 8-11 March 2011, agenda item 8) Korea Motor Vehicle Safety Standards Enactment/Revision Procedure for Automobile Management Act and Self Certification System DAM -> United nations e Download 172.3 Kb. Share with your friends:
|