2-Naphthylamine History (Late)

Historical Summary of 2-Naphthalene

Naphthalene is a white, crystalline powder with a characteristic odor. 2-Naphthylamine was commercially produced in the United States from at least the early 1920s to the early 1970s. It formerly was used commercially as an intermediate in the manufacture of dyes, as an antioxidant in the rubber industry, and to produce 2-chloronaphthylamine. Research into Naphthalene extends back to Ludwig Rehn’s study on the cuases of bladder tumors, and was continued by Wilhelm Hueper’s DuPont funded study of “Beta Naphthylamine”.

There is sufficient evidence for the carcinogenicity of 2-naphthylamine in experimental animals. When administered orally, 2-naphthylamine caused malignant bladder tumors in hamsters, dogs, and rhesus monkeys and liver tumors in mice; bladder tumors also were observed in rats at a low incidence Effects of naphthalene inhalation in humans include headache, confusion, eye irritation, nausea, profuse perspiration with vomiting, optic neuritis, hematuria, and edema. Naphthalene ingestion has resulted in abdominal pain, nausea, vomiting, diarrhea, darkening of the urine, irritation of the bladder, jaundice, anemia, and hyperthermia.

Naphthalene was nominated by NIOSH, OSHA, and EPA for carcinogenic evaluation because published evidence was inadequate for reaching a regulatory decision, and because of the potential for chronic exposure to humans through the use of mothballs in the home

Naphthalene has a boiling point of 217.9" C, a melting point of 80.2" C, a specific gravity of 1.14 at 4" C, a vapor pressure of 1 mm at 52.5" C, and vapor density of 4.4. It is insoluble in water. Chemical Formula: C10H8 Molecular Weight: 128.16

Specific Answers
Methodologies
Case studies were used for evidence of human carcinogens. Mouse and rat carcinogenicity bioassays were used. Both types of studies have been ongoing since the early 1900s.

Bias and Confounding

There is limited evidence of carcinogenicity from studies in humans, which indicates that causal interpretation is credible but that alternative explanations such as chance, bias or confounding factors could not adequately be excluded;

Sample Size
Varied according to test. The Sample size used in the below referenced mice study was

Detection Limits
The current Occupational Health and Safety Administration (OSHA) limit for naphthalene is 10 ppm in the air per 8-hour work shift. The American Conference of Governmental Hygienists reports that the odor threshold for naphthalene is at least as low as 0.3 ppm.

Dose-Response Relationships
Statistical analyses were conducted on the slopes of the dose-response curves and the individual dose points. An SCE frequency 20% above the concurrent solvent control value was chosen as a statistically conservative positive response. The probability of this level of difference occurring by chance at one dose point is less than 0.01; the probability for such a chance occurrence at two dose points is less than 0.001. An increase of 20% or greater at any single dose was considered weak evidence of activity; increases at two or more doses resulted in a determination that the trial was positive. A statistically significant trend (P<0.005)>

References: http://ntp.niehs.nih.gov/?objectid=07081648-F15B-C689-A21D232EED7BB32F
http://www.inchem.org/documents/iarc/suppl7/naphthylamine2.html

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10007

http://ntp.niehs.nih.gov/ntp/newhomeroc/roc11/NaphthalenePub.pdf

http://ntp.niehs.nih.gov/?objectid=BCBBF9C2-123F-7908-7B9242421803DAA9

The Hidden Picture

The Hidden Picture
There are interesting linkages. My background is in planning, and planning conducted in a vacuum is problematic. In essence, great plans can be drafted for neighborhoods and cities, however if the social, political, legal, and tangible considerations are ignored, the planning efforts will fail in large part because adjacent and subjacent sources were not considered. In traditional planning where economic development, housing, transportation and open spaces reign, a key component often overlooked lies between the areas of Emergency Management, Disaster-Vulnerability Planning, and Environmental Risks Assessment. An example of the overlap between the scientific precision of risk assessment, disaster-vulnerability planning, and traditional planning is in an area I resided and worked in for several years dubbed East St. Louis.

East St. Louis has a dual definition in the greater St. Louis area. In reality East St. Louis (ESL) is a conglomeration of towns and small villages anchored by the City of East St. Louis, IL. These communities all face in varying degrees traditional planning challenges. However there issues at work in this area which are not readily seen in familiar photos of the Greater St. Louis area. This area is a classic case of uncontrolled industry, toxic dumping, and faulty communications.

LaGrega’s Quantitative Risk Assessment outlines Risk Management by stating it must “entail consideration of political, social, economic, and engineering information with risk-related information to develop, analyze, and compare regulatory options and to select the appropriate regulatory response to a potential chronic health hazard.” This sounds a lot like disaster-vulnerability planning.

ESL was home to several major corporations including Alcoa, and Armor Meat Packing. Specifically, soil and sediment samples from old abandoned industrial sites revealed the presence of chlorobenzenes, chlorophenols, chloroanilines, nitroanilines, dioxins, and polychlorinated byphenols (PCBs). Many of these chemicals are in the waterways and have been found in the main channel of the Mississippi River. These water bodies are also used for recreational and commercial fishing. Other materials found throughout these abandoned areas are polynuclear aromatic hydrocarbons (PAHs), chlorophenols, nitroaniline, and several heavy metals that include cadmium, cobalt, copper, lead, mercury, nickel, and zinc.

The NPL’s Sauget Area 2 (which is inside of the ESL area) is roughly 312 acres of hazardous industrial, municipal, and chemical wastes substances. Examples of hazardous levels include:

· Benzene at concentrations up to 10,000 ug/kg
· Polychlorinated biphenyls (PCBs)) at concentrations up to 25,000,000 ug/kg
· 4,4'-Dichlorodiphenyethlene (DDE) at 270 ug/kg
· Phenol at 2,300,000 ug/kg
· Lead at 728 ug/kg.

These substances have been identified on the property, in groundwater beneath the property, and in Mississippi River sediments. These hazardous substances are potential threats to the people who consume the carp, catfish, and drum fish from the Mississippi River near the site.

The Monsanto Chemical Plant is an EPA Superfund site, heavily contaminated with PCBs and numerous other toxins.

The question remains, what is this area doing to correct these issues? Are these issues relevant? Do the residents know how serious the toxic problem is in their backyard? My hope is they would see (as LeGrega suggest) the interconnectedness of solving the environmental risk issues and reclaiming economic solvency for the area. Businesses which could possibly be interested in relocating in the area are not inclined to bring their companies into a hotbed of environmental toxins. Tourists are not interested in taking in the sights of dilapidated buildings or abandoned factories with a hint of almond scented toxins. A key element in the areas turnaround is the not-so-forgotten abandoned industry waste.

Pictures
http://www.mrhiggins.net/algebra2/
http://curtislowe.wordpress.com/2008/07/
http://www.builtstlouis.net/eaststlouis/sauget02.html
http://www.builtstlouis.net/eaststlouis/central-industrial03.html
Source Material
http://www.epa.gov/region5superfund/npl/illinois/ILD000605790.htm
http://www.epa.gov/region5superfund/npl/illinois/ILD980792006.htm

Aflatoxin - Late Assignment 7 by A. Reeve

In unfavorable conditions, of temperature and humidity, certain strains of Aspergillus flavus and A. parasiticus fungi, which grow on foods and feeds, will produce a toxic compound known as aflatoxins. Tree nuts, peanuts, and other oil seeds, such as corn and cottonseeds, seem to be more commonly associated with aflatoxins.

In 1965, George Buchi, Gerald Wogan, a group of toxicologist, and a group of organic chemists, identified aflatoxins as part of a collaborative effort at the Massachusetts Institute of Technology. They grew Aspergillus flavus mold on peanuts, then they isolated tiny amounts of the substances responsible for the poisonous properties of the groundnut meal. They named these substances in such a way to indicate their source, thus the origins of alfatoxins.

This team of scientists discovered that aflatoxin is a mixture of four different but closely related chemicals which contain the same molecular foundation of carbon, hydrogen, and oxygen atoms, yet differ slightly. These chemicals are designated as Aflatoxin B₁ (C₁₇H₁₂O₆) and B₂ (C₁₇H₁₄O₆), because they emit a blue florescence when irradiated with ultraviolet light; and Aflatoxin G₁ (C₁₇H₁₂O₇) and G₂ (C₁₇H₁₂O₇), because they emit a green florescence when irradiated with ultraviolet light. Aflatatoxin B₁ is the most toxic, and usually the more predominant, of these aflatoxins.

Scientists were having difficulty finding definitive proof of the harm aflatoxins posed to humans. They determined that the amount of aflatoxins reaching humans via foods were not as potent as those found in the contamined animal feeds, because they were processed, whereas the animal feed is not. However, studies conducted with a variety of animals have revealed that aflatoxins cause acute necrosis, cirrhosis, and carcinoma of the liver. Furthermore, it has been determined that there are no animal species which are resistant to the acute toxic effects of aflatoxins, thus it is a logical assumption that humans will be similarly affected.

In light of this evidence, the Food and Drug Administration (FDA) decided that products were unfit for human consumption if they contained in excess of 30 parts aflatoxin per billion parts of food (ppb). This standard was later dropped to 20 ppb. The decrease in the acceptable limits of human exposure to aflatoxin was due to improvements in analytical technology. In other words, when the FDA believes that there is no way to establish a completely safe level of human consumption for a cancer-causing agent, then any presence of the agent is unacceptable. Since the smallest amount of aflatoxin that could be detected was 30 ppb, that amount or an excess thereof was deemed to be unsafe. As technology improved, and smaller amounts of toxins could be detected, the limit changed to 20 ppb.

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REFERENCES

Rodricks, J.V., Calculated Risks: The Toxicity and Human Health Risks of Chemical in our Environment, Cambridge University Press, 2007, pp 3-6.

Reddy, S.V. & Farid Waliyar, Properties of Aflatoxin and its Producing Fungi, Retrieved from http://www.aflatoxin.ingo/aflatoxin.asp. 2000.

Walderhaug, M., Aflatoxins, U.S. Food & Drug Administration, Retrieved from http://www.cfsan.fda.gov/~mow/chap41.html. January 1992.