phe-bio-2 responses

Cryptosporidium is a biological agent that causes gastrointestinal illness.  Often referred to as ‘Crypto’, this parasite resides in the intestine of humans and animals (CDC, 2015).  Released through bowel movement via the infected animal(s) or individual(s), Cryptosporidium can be spread and contaminate drinking water a number of ways, including: “swallowing something that is contaminated with Crypto, swallowing recreational water contaminated with Crypto, eating uncooked food infected with Crypto, handling animals infected with Crypto, touching surfaces, handling diapers and caring for an infected individual” (CDC, 2015).  In 1993, the United States experienced the largest waterborne disease outbreak in Milwaukee, Wisconsin (Burlage, 2012, p.97).  The 1993 Cryptosporidium outbreak prompted public health officials to routinely monitor water supplies.  Commonly found in lakes and rivers, ozone and ultraviolet light are two of the most effective forms of treatment for averting the oocyst, which is, “the environmentally resistant form of the parasite” (Burlage, 2012, p. 97; EPA, n.d.).  Water is an essential component for all ecosystems.  From an ecological and environmental standpoint, Cryptosporidium can be transmitted and spread through contaminated food/water and/or recreational play (Burlage, 2012, p. 101).  Additionally, because the majority of our water supply is derived from surface water, it is important to understand the environmental factors associated with waterborne outbreak.

Reference

Burlage, R. S. (2012). Principles of public health microbiology. Sudbury, MA: Jones & Bartlett Learning.

Centers for Disease Control and Prevention. (2015). Sources of infection & risk factors. Retrieved from:https://www.cdc.gov/parasites/crypto/infection-sources.html

EPA. (n.d.). Ground water and drinking water. Retrieved from:https://www.cdc.gov/parasites/crypto/infection-sources.html

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Phe-bio-2 Response two

Arsenic is a toxic chemical element that is unequally distributed in the Earth’s crust in soil, rocks, and minerals. Arsenic occurs naturally in the environment and as a by-product of some agricultural and industrial activities.  It can pass into drinking water through the ground or as runoff into surface water sources. The U.S. Environmental Protection Agency (U.S. EPA) set an arsenic maximum contaminant level (MCL) for public water supplies at 0.010 mg/L. This is equivalent to 0.010 parts per million (ppm), 10 micrograms/liter (µg/L), or 10 parts per billion (ppb) (EPA, 2017). 

Arsenic, a metalloid and naturally occurring element, is one of the most profuse components found in the crust of the earth, as well as throughout our environment. Arsenic can attach to tiny particles in the air, stay in the air for many days, and travel long distances. It is predominantly used as an insecticide and herbicide due to its germicidal capacity and as a preservative for wood due to its resistance to rotting and decay. Arsenic is also utilized in medicine, electronics, and industrial manufacturing. In the environment, arsenic and its compounds are portable and impossible to destroy. Nonetheless, when it interacts with oxygen or other molecules existing in air, water, soil, or with bacteria that exist in soil or sediment, arsenic can change form, attach to different particles, or separate from these particles. Many ordinary arsenic compounds can dissolve in water, and have the ability to contaminate lakes, rivers, or underground water by dissolving in rain, snow, or through discarded industrial wastes. Thus, arsenic contamination in ground water is a dangerous public health threat globally, that has found to be associated with unfavorable health outcomes. Recently, the most substantial concern related to human health risks from arsenic toxicity is thought to be transported through drinking water, worldwide food distribution, smoking, and global cosmetics (Chung, Yu & Hong, 2014).

 Ground water is a major source of drinking water, and elevated concentrations of arsenic in ground water have been associated with various adverse health effects in humans. The most common source of arsenic contamination in ground water is the mobilization of naturally occurring arsenic on sediments (USGS, 2016). Given the correct chemical conditions in the subsurface arsenic can dissolve into ground water used for drinking water. Contamination of ground water is one of the chief conduits of human exposure to inorganic arsenic and the risk of arsenic contamination is in general much greater in ground water than in surface water. Elevated concentrations of arsenic have primarily resulted from natural sources, such as erosion and leaching from geological formations or anthropogenic sources. In addition, arsenic use for industrial purposes, mining activities, metal processing, and pesticides and fertilizers are other major sources of contamination (Chung, Yu & Hong, 2014).

Ruthie

References

 Chung, J., Yu, S., Hong, y.  (2014). Environmental Source of Arsenic Exposure. Journal of Preventaive Medicne and Public Health, 47(5), 253–257. doi: 10.3961/jpmph.14.036 

EPA. (2017). Retrieved from https://www.epa.gov/dwreginfo/chemical-contaminant-rules

USGS. Water Quality. (2016). Retrieved from https://toxics.usgs.gov/highlights/arsenic_gw/

Phe-bio-2-reponsse three

Arsenic is a chemical contaminant that is routinely monitored in drinking water. It is common throughout the earths crust, so people drinking from wells are at particularly high risk of having high levels of arsenic in their drinking water (World Health Organization). Arsenic can enter public drinking water systems through contamination by groundwater, and the problem varies regionally due to the varied arsenic concentrations in the earth's crust (World Health Organization). Environmental factors are especially important with regards to arsenic in drinking water, since certain environments are more susceptible to arsenic contamination due to the arsenic levels in the soil/earth of that region. The source of the drinking water is of concern as well; certain springs, wells, and bodies of water may have naturally occurring arsenic at levels that exceed what is safe. 

Reference