Environmental Chemicals Review

This post is intended as a review of the chemicals presented (Benzene link) and discussed by Environmental Science students at UNT.

Hexavalent Chromium: A natural element in its Hexavalent state. This particular state is very toxic. It has occurred as a water contaminant, and causes a wide range of adverse health effects, including cancer.

Arsenic: Another natural element, found in the earth’s crust. It is water soluble and has been a problem when drinking water sources have been contaminated, or in areas where the concentration is naturally high. Its most well-known adverse effect is skin cancer (in chronic exposures). It has also been used as a pesticide, especially before the synthesis and widespread availability of organochlorine and organophosphate pesticides.

Beryllium: also an element present naturally in the earth’s crust. It has been a problem for human health when workers are exposed in occupational settings, or when the families of workers have been exposed by contaminated clothing. Exposure occurs through respiratory routes, and can make the immune system hypersensitive. Such hypersensitivity can result in overly strong allergic responses, or in autoimmune diseases such as asthma, thyroid disorders, and rheumatoid arthritis.

Cadmium: an element, not normally an environmental problem unless it has been concentrated by human activities. Cadmium fumes can cause lung and kidney damage. It also causes cancer.

Mercury: more elemental evil. It is rare in the earth’s crust, but is concentrated anthropogenic means (by human activities), where it has become a problem for humans as well as other species. When methylated (by anaerobic bacteria) it bioaccumulates and targets the nervous system. It can also be hazardous when inhaled.

Flouride: appears to increase bone strength at low levels, but at higher levels may make them brittle, and will cause stained splotched teeth. There have been some correlative studies looking at high fluoride intake and reduced IQ in children, but the jury is still out. This will be an interesting issue to follow. For more information try:
http://dels.nas.edu/resources/static-assets/materials-based-on-reports/reports-in-brief/fluoride_brief_final.pdf

Benzene: is a volatile compound that may be found naturally in gas deposits, may form in combustion, but is also synthesized for commercial uses. Environmental exposures are associated with increased incidence of Spina Bifida in infants. Industrial exposures are associated with Leukemia and Aplastic Anemia (this is often fatal as well). Although benzene is non-polar and lipophilic it does not bioaccumulate. This is because of its volatility, which allows it to be exhaled in breath. It also undergoes biotransformation, which means it is not as persistent as other cyclic compounds such as lindane. For more info: http://www.atsdr.cdc.gov/ToxProfiles/tp3-c6.pdf This is for your interest, and will not be on the exam.

Asbestos: a natural mineral that causes micro-damage and inflammation in human tissues. This is especially problematic for lungs, as inhalation is the primary route of exposure.

Oxybenzone: Not to be confused with Benzene. It is used in sunscreen and other personal care products. It is an endocrine disruptor, and also appears to be damaging to coral reefs. For more information try: http://www.ewg.org/news/can-sunscreen-lead-hormone-damage-kids

Particulate matter: is a hot topic right now, and you can be sure there will be a lot of interesting studies coming out in the near future as people try to figure out how particulates may adversely impact human health. Exposure to particulates is associated with increased cardiovascular disease, increased risk of arthritis and other immune disorders, and number of other problems.

Estrogens in aquatic systems: causes induction of intersex in fish, and may cause problems for humans and other organisms as well.

Organophosphates: These are a class of synthetic pesticides (and nerve agents) that target the nervous system. Exposures, if sufficiently high, will produce the SLUDGE syndrome (salivation, lacrimation, urination, defection, Gastrointestinal distress and emesis). Chronic, lower level exposures, may cause Delayed Onset Peripheral Neuropathy and are associated with increased risk of Parkinson’s disease.

Formaldehyde: used in fraking and in personal care products, as well as in various other industrial applications. Formaldehyde is classified as a “probably carcinogen”. Exposures have occurred industrially, but also in people exposed to off-gassing of formaldehyde-contaminated temporary housing.
It is also a respiratory irritant and may induce asthma. For more info try:
http://toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb:@term+@rn+@rel+50-00-0
If you would rather get depressed try:
http://junkscience.com/2011/04/10/victory-lap-junkscience-com-knocks-off-another-junk-scientist/

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