Like many places in the world, water quality is an issue here in northern New England. Our ocean beaches and rivers are a source of tourist revenue and recreation for locals, so we have town Conservation Commission volunteers taking water samples a few times every week, trying to pinpoint sources of pollution into our streams and onto our seashore.
The water samples are sent to a local lab for analysis, then plans of action are drawn up. Oftentimes, a strategy for abatement involves a homeowner, local farmer, or horse rancher. Farm runoff from animals and defective septic systems are sometimes pinpointed as culprits where high bacterial counts are found.
One of the techniques used to determine if a septic system or treatment plant is polluting a watercourse is the detection of so-called
optical brighteners. These dyes are found in water that contains effluent from a home laundry. The optical brighteners actually enter the hydro-environment as a result of ineffective treatment, such as a failing private septic system.
The brighteners are fluorescent dyes added to laundry detergents by soap vendors. You see (or maybe you don't), cotton absorbs the blue portion of the spectrum, so when optical brighteners are applied to cotton fabrics, they absorb UV in sunlight and then re-release the light as blue. The blue then interacts with the dingy color of the fabric, making it look whiter than white. It's literally a case of now you see it, now you don't.
The Massachusetts-based Ipswich Coastal Pollution Control Committee and the Gloucester Shellfish Department and Advisory Commission
found that optical brightener testing is a good indicator to help identify malfunctioning private septic systems or public sewage treatment plants.
As such, the presence of optical brighteners is now part of the test regimen in my town when our volunteers attempt to trace sources of water pollution. The technique works rather well, because the brighteners can be detected at low levels with relatively simple instruments based on ultraviolet incandescent bulbs, or black lights.
Stinky Feet?Thankfully, optical brighteners per se don't have a negative effect on water quality, but silver and copper nanoparticles may be another story. Silver nanoparticles, under 100 nm in size, are now being
added to socks, with sock makers extolling their virtues for destroying foot odor.
Yes, silver nanoparticles kill a sock's odiferous bacteria, but they also get into laundry water, and eventually find their way into streams, rivers, and beaches. That wouldn't be too bad, but unlike optical brighteners, silver nanoparticles may harm aquatic organisms.
Researchers at
Arizona State University (ASU) actually tested socks containing silver antibacterial nanoparticles. They found that many brands lost nearly all of their silver content within a few launderings. As for public wastewater plants, ASU models indicated that silver nanoparticles from water treatment plants should be within the levels established by the US Environmental Protection Agency, but accumulated sludge might contain much higher silver concentrations. Ironically, the fear is that the silver particles may actually destroy the helpful bacteria in water treatment facilities that's needed to cleanse the water.
Copper
nanoparticles may also harm aquatic life, especially affecting fish gills. Studies on rainbow trout at England's University of Plymouth reveal that fish suffer respiratory problems when exposed to copper nanoparticles. A team at the University of Florida also concluded that copper nanoparticles are acutely lethal to fish, and at low concentrations.
These nanoparticles, also called nanodots and nanopowder, are spherical particles with very high surface areas. Like their silver counterparts, copper nanoparticles typically measure from about 10 nm to 100 nm in size. They may ultimately be used in applications in nanoelectronics and photonics, especially for MEMS (microelectromechanical systems) and NEMS (nanoelectromechanical systems). Applications are foreseen for use as biomarkers and biosensors, and for making polymers, textiles, fuel cells, composite materials, and solar panels.
It looks like nanoparticles will soon become a common constituent of many products. If so, and they end up in waterways and wastewater treatment plants, it's possible their long-term effect could impact more than stinky feet and fish gills.
