1 in 5 teens have hearing loss

[Guest guest]

http://www.latimes.com/news/science/la-sci-teens-hearing-loss-20100818,0,559994.\

story

" Can you hear me now? More teens can't

One in every five teens has at least a slight hearing loss. Many experts suspect

the primary cause is the use of headphones to listen to portable music. "

Alternative explanation: mercury toxicity.

" Hearing loss is described as a common part of the clinical picture in acute and

chronic methyl-mercury poisoning. Both cochlear and postcochlear lesions have

been involved (Oyanagi et al. 1989). Inorganic mercury may also affect the

auditory system, probably through damage to cochlear structures. "

Encyclopaedia of Occupational Health And Safety I

See also:

1: Neurotoxicol Teratol. 2003 Jan-Feb;25(1):69-76. Links

Neurotoxic effects of mercury on auditory cortex networks growing on

microelectrode arrays: a preliminary analysis.

Gopal KV.

Department of Speech and Hearing Sciences and Center for Network Neuroscience,

University of North Texas, PO Box 305010, Denton, TX 76203, USA. gopal@...

Mercury is known to cause sensorineural hearing loss and impaired speech

perception. However, there is still a lack of a quantitative description of

mercury toxicity on central auditory structures. This is a preliminary study

using the novel technique of microelectrode array (MEA) recordings to evaluate

acute and chronic neurotoxic effects of mercury on auditory cortex networks

(ACNs) in vitro. Morphological and electrophysiological effects of mercuric

chloride (HgCl(2)) were studied.Neurons dissociated from auditory cortices of

14-day-old mouse embryos were grown on photoetched MEAs containing 64

transparent indium-tin oxide (ITO) electrodes. For acute electrophysiological

experiments, the spontaneous spiking and bursting activity from ACNs were

compared before and after application of HgCl(2). For chronic

electrophysiological experiments, auditory cortex cultures were treated with

various concentrations of HgCl(2) from the day of seeding, and were tested 4

weeks later for the presence of spontaneous activity. Morphological analysis was

conducted on 8-day-old ACNs treated with HgCl(2) for 3 days. Results of acute

experiments indicated that <75 mM of HgCl(2) had an excitatory effect of

variable magnitude on the spontaneous activity of ACNs; however, concentrations

above 100 microM completely and irreversibly inhibited spike and burst activity.

Chronic exposure of ACNs to 10 microM HgCl(2) completely blocked the spontaneous

activity. Morphological analysis indicated that 10 microM HgCl(2) caused

neuronal cell death in 3 days. It is concluded that HgCl(2) has a more toxic

effect on auditory networks when exposed chronically, and the levels of mercury

showing toxic effects on ACNs are within the dose range shown to cause

neurologic symptoms in humans.

PMID: 12633738 [PubMed - indexed for MEDLINE]

----

Also from the article:

" For unknown reasons, children with light blue eyes are more likely to suffer

hearing loss than those with other eye colors. "

This struck me as interesting and curious given the anecdotal reports I have

read on various autism listservs that blonde boys with fair skin, blue eyes seem

particularly common (according to some parents) among those diagnosed with

autism. I don't know if that observation is accurate or not.

[Guest guest]

Now, we hear in Canada, that many of us have BPA and mercury in our blood. Yet, our "Health Canada" tells us not to worry. That would be THEIR stance, as they are likely as closely intertwined with the various industries, as the FDA is in the States with their counterparts (IMO).

http://cnews.canoe.ca/CNEWS/Politics/2010/08/16/15036771.html

Aasa

Subject: 1 in 5 teens have hearing lossTo: EOHarm Date: Wednesday, August 18, 2010, 12:50 AM

http://www.latimes.com/news/science/la-sci-teens-hearing-loss-20100818,0,559994.story"Can you hear me now? More teens can'tOne in every five teens has at least a slight hearing loss. Many experts suspect the primary cause is the use of headphones to listen to portable music."Alternative explanation: mercury toxicity."Hearing loss is described as a common part of the clinical picture in acute and chronic methyl-mercury poisoning. Both cochlear and postcochlear lesions have been involved (Oyanagi et al. 1989). Inorganic mercury may also affect the auditory system, probably through damage to cochlear structures."Encyclopaedia of Occupational Health And Safety ISee also:1: Neurotoxicol Teratol. 2003 Jan-Feb;25(1):69-76. LinksNeurotoxic effects of mercury on auditory cortex

networks growing on microelectrode arrays: a preliminary analysis.Gopal KV.Department of Speech and Hearing Sciences and Center for Network Neuroscience, University of North Texas, PO Box 305010, Denton, TX 76203, USA. gopal@...Mercury is known to cause sensorineural hearing loss and impaired speech perception. However, there is still a lack of a quantitative description of mercury toxicity on central auditory structures. This is a preliminary study using the novel technique of microelectrode array (MEA) recordings to evaluate acute and chronic neurotoxic effects of mercury on auditory cortex networks (ACNs) in vitro. Morphological and electrophysiological effects of mercuric chloride (HgCl(2)) were studied.Neurons dissociated from auditory cortices of 14-day-old mouse embryos were grown on

photoetched MEAs containing 64 transparent indium-tin oxide (ITO) electrodes. For acute electrophysiological experiments, the spontaneous spiking and bursting activity from ACNs were compared before and after application of HgCl(2). For chronic electrophysiological experiments, auditory cortex cultures were treated with various concentrations of HgCl(2) from the day of seeding, and were tested 4 weeks later for the presence of spontaneous activity. Morphological analysis was conducted on 8-day-old ACNs treated with HgCl(2) for 3 days. Results of acute experiments indicated that <75 mM of HgCl(2) had an excitatory effect of variable magnitude on the spontaneous activity of ACNs; however, concentrations above 100 microM completely and irreversibly inhibited spike and burst activity. Chronic exposure of ACNs to 10 microM HgCl(2) completely blocked the spontaneous activity. Morphological analysis indicated that 10 microM HgCl(2) caused neuronal cell

death in 3 days. It is concluded that HgCl(2) has a more toxic effect on auditory networks when exposed chronically, and the levels of mercury showing toxic effects on ACNs are within the dose range shown to cause neurologic symptoms in humans.PMID: 12633738 [PubMed - indexed for MEDLINE]----Also from the article:"For unknown reasons, children with light blue eyes are more likely to suffer hearing loss than those with other eye colors."This struck me as interesting and curious given the anecdotal reports I have read on various autism listservs that blonde boys with fair skin, blue eyes seem particularly common (according to some parents) among those diagnosed with autism. I don't know if that observation is accurate or not.