One of the many dangerous elements that are in our environment is Lead (Pb). Lead is introduced into the environment through many processes including refining and smelting of lead ores, the passage of soft water through lead pipes and the unsafe disposal of lead-acid batteries (car batteries), insecticides and high octane gasoline.
Once in the environment, lead undergoes little chemical change with the vast majority of it being in the form of aqueous Pb 2+ ions or insoluble lead (II) compounds. Lead is a cumulative poison in human beings that binds strongly to enzymes, proteins, RNA and DNA which results in the disruption of many metabolic pathways. It may cause nervous system disorders and brain or kidney damage and is especially hazardous to the fetus or to children. This issue shows the importance of testing for lead in our waterways.
The state standard for lead is divided into two categories: 1) freshwater and 2) saltwater. Our freshwater sites are 1 through 3 and must not exceed .029 mg/L. Our saltwater sites are 4 through 8 and must not exceed .140 mg/L.
Currently the He'eia Stream lead data is minimal and a pattern has yet to emerge. The only site that can be used to determine any pattern is Stream Mouth. Stream Mouth data exceeds the acute levels for each sampling date which most likely is determined by the location of this site. Stream Mouth is located in close proximity to Kamehameha Highway which handles a steady amount of vehicle traffic. Not only do the emissions cause impact on lead levels but any runoff from the road will wash the settled lead particles directly into the stream near this site.
Rainfall does not appear to be a factor in the increased levels of lead. March and April have the highest monthly levels of rainfall. The data shows that there was minimal impact on all sites in these months except Stream Mouth.
An examination of this data shows that lead needs to be monitored closely in the succeeding months, then a pattern may develop. This pattern can then assist us in mitigating any further increases in the lead levels.