Heavy Metals in Bird Water Sources at the Lorrimer Sanctuary
Introduction
Lead alone is estimated to kill more than 20 million birds annually in the United States. Heavy metals like copper, lead, and mercury are often not considered as sources of toxicity to birds because they appear in low concentrations in water. Heavy metals get into water sources from aquatic ecosystems like rocks and soils, but mainly from human contributions like industrial pollutants/ oil spills, mining, sewage and other forms of pollution.
Consequently, birds that regularly consume water containing heavy metals become poisoned. When ingested in high volumes, heavy metals damage nerves, causing maldigestion, nausea/ vomiting, and neurological abnormalities such as paresis/ paralysis, seizures, and similar symptoms. Among heavy metals, copper, lead, and mercury are of the highest threat to birds, interfering with enzymes inside cells of organs. A recent research study from Veterinary Center for Birds and Exotics suggests digestion of heavy metals impacts nearly every major organ such as hematopoietic, immune systems, lungs, kidneys, renal, nervous, and cardiovascular systems.
However, low levels of toxicity in birds are treatable if diagnosed before nerve damage. Thus, testing for heavy metals can provide bird owners and wetland conservationists with a comprehensive understanding of the water source relied upon by birds.
The purpose of this study is to measure heavy metals in bird water sources. At the Audubon Center, we will use reagent test strips from Med Lab Diagnostics, to detect traces of copper, lead, and mercury. Using the color chart, we can identify the concentration of the heavy metals present in the water sample. The water sample is hazardous if copper is present in amounts above 5 μg/L, if lead is present above 5 μg/L, and if mercury is present above 2 μg/L. It can be predicted that all heavy metals will be present in some trace at the water source, as a recent research report, Environmental Contamination by Heavy Metals, written by V. Masindi and K.L. Muedi, states, “heavy metals are usually present in trace amounts in natural waters.” With our findings and data, we can further conservation efforts toward protecting birds and preventing illness.
Materials and Method
Test strips for copper, lead, and mercury were fully submerged into water for 1-2 seconds. Immediately after, excess water was carefully wiped off and stripes were processed for 30 seconds. It is important to not wait more than 30 seconds, as samples may lose accuracy. Using the color chart, the reaction areas were identified to depict the amount of heavy metals present in the water sample.
Results
The data above presents the amounts of lead, copper, and mercury levels detected using the Med Lab Diagnostics reagent test strips. Each heavy metal was tested five times to ensure consistency among results. On average, 4 μg/L of copper, 3 μg/L of lead, and 3.8 μg/L of mercury were detected. Recommended levels, taken from Med Lab Diagnostics, were compared besides the heavy metals tested.
Discussion
We tested for traces of copper, lead, and mercury in a bird water source. We hypothesized that all heavy metals tested will be present in some trace at the water source. We found all heavy metals present, mostly in low concentrations that are non-hazardous to birds. Med Lab Diagnostics reports that levels of copper and lead above 5 μg/L and levels of Mercury above 2 μg/L are hazardous to birds. It was found that copper and lead, both possessing average concentrations of 4 μg/L, were below levels of toxicity to birds. However, mercury was recognized at 3.8 μg/L, which is above what Med Lab Diagnostics report as safe.
While a percentage of accuracy for the reagent test strips is not confirmed, Med Lab Diagnostics comments, “Our Water test strips provide accurate results for testing various sources.”
These results were likely due to a railroad track that was located at the end of the water source. Coal pollutants from trains that pass the water source are likely to fall into waterways
and agricultural spaces because the companies that transport coal do so in uncovered, exposed rail cars. Coal is harmful because it contains mercury, lead, copper, and other toxic heavy metals. A research report from the Burlington Northern Santa Fe Railway estimates that 500 to 2,000 pounds of coal is likely to escape from a single coal car, depending on a number of factors like the weather.
Aside from coal pollutants, human contributions such as industrial pollutants, oil spills, mining, sewage, and other forms of pollution commonly involve heavy metals which can also escape, polluting waterways and agricultural spaces. Additionally, heavy metals could have accessed the water source from aquatic ecosystems such as rocks and soils.
The experiment was intentionally designed to eliminate confounding variables. However, a possible error could have been the time constraint under which we had to submerge the reagent strips under water and analyze within 30 seconds.
The experiment can be replicated by testing for the same heavy metals/ adding more trials. The experiment can be extended by casting a wider net of heavy metals tested, such as nickel, tin, cadmium, arsenic, and similar elements.
Application to STEM
Works Cited
“10 Everyday Items That Are Toxic to Birds.” Veterinary Center for Birds and Exotics, 13 Nov. 2018, avianexoticsvet.com/10-everyday-items-that-are-toxic-to-birds/.
“Coal Dust Frequently Asked Questions.” BNSF Railway, 2 Mar. 2011, 3:10:11 PM, www.coaltrainfacts.org/docs/BNSF-Coal-Dust-FAQs1.pdf.
Masindi, Vhahangwele, and Khathutshelo L. Muedi. “Environmental Contamination by Heavy Metals.” IntechOpen, IntechOpen, 27 June 2018, www.intechopen.com/books/heavy-metals/environmental-contamination-by-heavy-metals.
Mock, Jillian, and September 19. “North America Has Lost More Than 1 in 4 Birds in Last 50 Years, New Study Says.” Audubon, 20 Sept. 2019, www.audubon.org/news/north-america-has-lost-more-1-4-birds-last-50-years-new-study-says.
*All graphics, unless explicitly marked, were taken by Harrison James.