There are numerous regulations in place that limit the amount of toxic compounds and metals that can be released into the atmosphere. XRF lends itself to many important analytical applications in support of these regulations.
Here are a few common environmental applications:
· Lead in Paint- Lead was long used in paint until it was found to be a leading cause of lead poisoning among children and people who work on the exteriors of older buildings. Thousands of hand held EDXRF instruments have been sold to meet lead in paint monitoring regulations.
· Air Filter Analysis- Internationally there are many air monitoring programs that look for respirable particulates in the air. They analyze for every conceivable element with close attention being paid to toxic metals. High-resolution EDXRF instruments with large quantity sample changers are made for this application.
· Soil Screening and Analysis- At wood treating facilities chromium, arsenic and pentachlorophenol may seep into the ground; in plating shops it may be chromium, while toxic metals such as lead, mercury, arsenic and cadmium contaminate numerous other sites. XRF is commonly used as a screening tool to identify grossly contaminated areas that must be remediated. Smaller EDXRF instruments, even hand held devices might be used on site, while higher end instruments are used in the lab.
· On-site and Stack Air Monitoring- Workers are often exposed to toxic particulates in the air like lead or uranium. A portable air sampler can take field samples that can be analyzed by a portable or laboratory XRF instrument. Similar samples air taken at stacks to monitor industrial emissions. The sampling system can be integrated to make this an on-line application as well. Some elements such as sulfur can be measured directly in the vapor phase.
· Waste Water- XRF can be used for analyzing metals in wastewater, such as silver emulsion from a photo lab.
· Tissue Samples- Tissue samples are monitored for toxic metal contamination as a way to monitor the safety of the environment. Fish are commonly analyzed for metals like mercury in order to determine water quality and ascertain if the fish are edible.
· PCB’s in soil- In areas of know PCB contamination where the soil is naturally low in chlorine, XRF can be used as a screening tool for PCB’s.