re: carbon monoxide: Month of Conception and Risk of Autism

[Guest guest]

In response to my post (hereinbelow) about carbon monoxide in the home

as possibly relevant to autism's time trends per year (1a), a physician

commented, " If so, the same mechanism as with smoking cigarettes? "

Given that CO is not the only adverse factor implicated in smoking, I

found 31 cites via

autis*[tw] AND (smoking[tw] OR tobacco[tw])

At least one such cite found " low ventilation rate in the home " to be

associated with autism (2a), a finding consistent with the possibility

that carbon monoxide is among background factors contributing to the

findings of Zerbo et al (1a).

*/

/*

1a. Month of Conception and Risk of Autism.

<http://www.ncbi.nlm.nih.gov/pubmed/21543984>

Zerbo O, Iosif AM, Delwiche L, C, Hertz-Picciotto I.

Epidemiology. 2011 May 3.

" Higher risks for autism among those conceived in winter months suggest

the presence of environmental causes of autism that vary by season. "

2a. Associations between indoor environmental factors and

parental-reported autistic spectrum disorders in children 6-8 years of

age. <http://www.ncbi.nlm.nih.gov/pubmed/19822263>

Larsson M, Weiss B, Janson S, Sundell J, Bornehag CG.

Neurotoxicology. 2009 Sep;30(5):822-31.

An analysis of the associations between indoor environmental variables

in 2000 as well as other background factors and the ASD diagnosis

indicated five statistically significant variables: (1) maternal

smoking; (2) male sex; (3) economic problems in the family; (4)

condensation on windows, a proxy for */low ventilation rate in the

home/*; (5) PVC flooring, especially in the parents' bedroom.

> 2011/5/8 Binstock <binstock@...

> >

>

> Perhaps (along with maternal vaccinations for influenza) /in-home

> carbon monoxide/ is a factor (eg, 1-8), as homes would have

> windows closed more often, furnaces running more often.

> *

> About CO standards and CO monitors*

>

> My CO monitors have been chirping occasionally for weeks. During

> that time I've had many conversations with home-heating

> specialists - who have devices that can detect and report CO

> levels as low as 1 ppm. One day, with a reading of 14 ppm, the

> technician said I ought be sensing symptoms such as fatigue,

> dizziness. (I was).

>

> In-home CO detectors are set to sound after hours of 70 ppm,

> shorter times for higher levels. The easily available CO detectors

> with digital readouts do so at 30 ppm and above but sound after

> hours of 70 ppm. However, the technician said I ought be sensing

> symptoms in the vicinity of 14 ppm.

>

> An EPA CO site (here <http://www.epa.gov/iaq/co.html>) offers

> diverse guidelines, including concern for 8-hour levels of 55, 35,

> or 25 ppm (9).

>

> *Questions*

>

> Is the 70 ppm standard for home-detectors an industry-serving

> fiction?

>

> Is in-home carbon monoxide is factor influencing embryonic

> development in an autism direction?

>

> /**/

>

> 1-7 via:

> " carbon monoxide " [tw] AND embry*[tw] AND (neuron* OR brain OR CNS)

>

> 1. Evidence for oxidative stress in the developing cerebellum of

> the rat after chronic mild carbon monoxide exposure (0.0025% in

> air). <http://www.ncbi.nlm.nih.gov/pubmed/19580685>

> IA, Acuna D, Beltran-Parrazal L, IE, Amarnani A,

> Cortes M, Edmond J.

> BMC Neurosci. 2009 May 27;10:53.

>

> 2. Chronic prenatal exposure to carbon monoxide results in a

> reduction in tyrosine hydroxylase-immunoreactivity and an increase

> in choline acetyltransferase-immunoreactivity in the fetal

> medulla: implications for Sudden Infant Death Syndrome.

> <http://www.ncbi.nlm.nih.gov/pubmed/10744060>

> Tolcos M, McGregor H, D, Rees S.

> J Neuropathol Exp Neurol. 2000 Mar;59(3):218-28.

>

> 3. Exposure to prenatal carbon monoxide and postnatal

> hyperthermia: short and long-term effects on neurochemicals and

> neuroglia in the developing brain.

> <http://www.ncbi.nlm.nih.gov/pubmed/10739630>

> Tolcos M, Mallard C, McGregor H, D, Rees S.

> Exp Neurol. 2000 Apr;162(2):235-46.

>

> 4. A delayed role for nitric oxide-sensitive guanylate cyclases in

> a migratory population of embryonic neurons.

> <http://www.ncbi.nlm.nih.gov/pubmed/9851840>

> JW, Schwinof KM, Snyder MA, Copenhaver PF.

> Dev Biol. 1998 Dec 1;204(1):15-33.

>

> 5. Ornithine decarboxylase activity in fetal and newborn rat

> brain: responses to hypoxic and carbon monoxide hypoxia.

> <http://www.ncbi.nlm.nih.gov/pubmed/8306425>

> Packianathan S, Cain CD, Stagg RB, Longo LD.

> Brain Res Dev Brain Res. 1993 Nov 19;76(1):131-40.

>

> 6. Carbon monoxide and brain development.

> <http://www.ncbi.nlm.nih.gov/pubmed/3537859>

> Fechter LD, Mactutus CF, Storm JE.

> Neurotoxicology. 1986 Summer;7(2):463-73.

>

> 7. Chronic low level maternal carbon monoxide exposure and fetal

> growth and development. <http://www.ncbi.nlm.nih.gov/pubmed/687711>

> Garvey DJ, Longo LD.

> Biol Reprod. 1978 Aug;19(1):8-14.

>

> 8. Carbon monoxide and the nervous system.

> <http://www.ncbi.nlm.nih.gov/pubmed/12667497>

> Raub JA, Benignus VA.

> Neurosci Biobehav Rev. 2002 Dec;26(8):925-40.

>

> 9. EPA

> http://www.epa.gov/iaq/co.html

>

> [OSHA PEL] The current Occupational Safety and Health

> Administration (OSHA) permissible exposure limit (PEL) for carbon

> monoxide is 50 parts per million (ppm) parts of air (55 milligrams

> per cubic meter (mg/m(3))) as an 8-hour time-weighted average

> (TWA) concentration [29 CFR Table Z-1].

>

> [NIOSH REL] The National Institute for Occupational Safety and

> Health (NIOSH) has established a recommended exposure limit (REL)

> for carbon monoxide of 35 ppm (40 mg/m(3)) as an 8-hour TWA and

> 200 ppm (229 mg/m(3)) as a ceiling [NIOSH 1992]. The NIOSH limit

> is based on the risk of cardiovascular effects.

>

> [ACGIH TLV] The American Conference of Governmental Industrial

> Hygienists (ACGIH) has assigned carbon monoxide a threshold limit

> value (TLV) of */25 ppm/* (29 mg/m(3)) as a TWA for a normal

> 8-hour workday and a 40-hour workweek [ACGIH 1994, p. 15]. The

> ACGIH limit is based on the risk of elevated carboxyhemoglobin

> levels [ACGIH 1991, p. 229].

>

>

>

>

>

>