With a slight editorial modification, your last proposal is the best: have more cyclists collect discarded weights. And we would be healthier too! Bob Hilty Tyco Electronics > -----Original Message----- > From: Brian Ellis [SMTP:[log in to unmask]] > Sent: Friday, May 04, 2001 8:14 AM > To: [log in to unmask] > Subject: Re: [LF] Lead in Ammunition; EPA TRI ruling > > Bruce > > Let us imagine that your friend collects just 1% of all the weights cast > in the SF area. That means that the total is in the region of 1.5 > tonnes. I don't have a hydrological map of SF bay handy, but I imagine > we are talking about at least 100 km3 of water, probably a lot more, > i.e. 10^11 tonnes. Just for the sake of argument, let us assume the lead > from those weights all dissolves instantaneously into the bay. Result: a > very small fraction of ppb, nearly ppt. However, it will be even less a) > because the water in the bay is not static because it is being > constantly replaced as water flows into the bay from land sources > (including treated waste water) and by tidal flushing; b) lead will not > dissolve instantaneously ; c) the solubility of lead in sea water is > lower than in pure water (cf lead artefacts recovered from 3000 year old > shipwrecks in the Mediterranean). Even if my original hypothetical > estimations are way out, there is plenty of margin to show that there is > absolutely no risk of SF Bay becoming sterile because of this source. In > reality, the geology of the region is probably such that the number of > tonnes of lead washed down in alluvium during the rains will be many > times all the lead dropped off wheels in the whole of California. > > Let's keep a sense of proportion. > > However, there are ways of mitigating your hypothetical problem: a) > force tyre manufacturers to make their products so that less wheel > balancing is required; b) force weight manufacturers to redesign the > clips, so that the weights don't come off; c) replace the lead by tin > (see http://www.itri.co.uk/wweights.htm ) and d) have more cyclists > collect discarded weights. > > Brian > > -------------------------------------------------------------------------- > ------- > Leadfee Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Leadfree > To temporarily stop delivery of Leadree for vacation breaks send: SET > Leadfree NOMAIL > Search previous postings at: www.ipc.org > On-Line Resources & Databases > > E-mail Archives > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > -------------------------------------------------------------------------- > ------- --------------------------------------------------------------------------------- Leadfee Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Leadfree To temporarily stop delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------