This past October I attended the Soils Conference at the University of Massachusetts and was fortunate enough to sit in on a number of excellent presentations. Despite this positive experience, I was planning to leave early on the last day of the conference, but as I thought about my cluttered desk and pile of unanswered messages back at the office, I decided to stay a little longer and hear three presentations on vapor intrusion assessment.  This proved to be a very good decision as each of them was outstanding.

New VI Assessment Method

The first of these presentations was given by Ms. Lila Beckley of GSI Environmental in Austin Texas; her title was “Vapor Intrusion (or Not): Sniffing out the Source of VOCs in Indoor Air”.   She described a new method for assessing vapor intrusion (new to me anyway) and gave an eye opening description of their techniques.  Her firm has developed a vapor intrusion assessment method that uses real time sampling and analysis of indoor air while the pressure within the building is adjusted from positive to negative.  Based on the pattern of change observed in VOC air concentrations as the pressure is reduced, it was possible to determine whether the VOCs were truly from vapor intrusion or whether they actually originated from a source within the building. 

This technique represents a significant improvement over the methods previously used to assess vapor intrusion. 

A Specialized Application of the Same Technique

Following a short break, there was a presentation on vapor intrusion assessment by Mr. David Shea of Sanborn, Head & Associates that used the same general technique described by Beckley, but with the additional objective of identifying specifically how and where vapor intrusion was taking place in a large building located over a known groundwater contaminant plume.  The example used in Shea’s presentation nicely complemented and expanded on the methods illustrated in the previous talk. 

In summary, both presenters described a highly credible method that appears to quickly and accurately assess vapor intrusion.  The method requires only a 1-2 day assessment, but does need to be conducted with sensitive specialized field instruments.  The method seems capable of differentiating between indoor sources of VOCs in air and those originating from a sub-slab source.

How Good is the Correlation between Sub-Slab VOC Concentrations and Vapor Intrusion?

The last of these three talks was given by Mr. Ben Matrich of Geosyntec Consultants’ Anchorage Alaska office.  His title was “The Case for Less Emphasis on Sub-Slab Data in Decision Making for the Vapor Intrusion Pathway”.  The thrust of his presentation was that investigators have come to place too much emphasis on sub-slab soil gas measurements without adequately understanding their limitations.  The scientific basis for his talk comes from the comprehensive vapor intrusion research the USEPA has sponsored at Sun Devil Manor, a house purchased for this purpose in Layton, Utah.  Investigators are using the Sun Devil Manor (which is located over a contaminated aquifer) to study the detailed mechanisms of how vapor intrusion takes place; the results have upset much of the old thinking about vapor intrusion.

Details of the findings go beyond what I have space for here, but here are some examples.  EPA found that at Sun Devil Manor sub-slab soil gas concentrations can vary more than expected over time, as can the indoor air concentrations caused by vapor intrusion.  Temperature, barometric pressure and wind speed can all strongly affect vapor intrusion rates as well as the resulting indoor air VOC concentrations. Of course these findings all come from a single location and may not be generally applicable.


The simple vapor intrusion models used to develop the early regulatory efforts to limit the vapor intrusion pathway are being revised based on new studies and assessment techniques.  It is reasonable to expect that the approach to vapor intrusion will continue to evolve as additional research is published.

A week ago I received an email letting me know that one of my all-time favorite restaurants was closing, the Night Kitchen in Montague, Massachusetts.  To say that Montague is off the beaten track is a gross understatement.  Explaining to the non-native that Montague is about half way between Sunderland and Turner’s Falls usually results in blank stares.

Night Kitchen is located in the lower level an old mill complex that sits on the bank of the Sawmill River.  Upstairs is a used bookstore whose slogan is “Books you don’t need in a place you can’t find”. The restaurant is accessed by a wooden stairway right beside the river.  Although my wife likes to remind me that I haven’t always raved about the food (usually I have though – incomparable gnocchi and lamb shanks), the setting is so perfect and the staff so superlative that I will always remember it fondly.

The restaurant was started about ten years ago by Max Brody, who had learned his cooking skills in France.  After I got the sad news last week,  my wife indulged me and we ran up to Montague last Sunday afternoon for a last meal – which was great by any standard.  We were lucky enough to run into Max, his wife and child who were having dinner at the bar.   We expressed our appreciation for all his work and he explained that it was just too hard to have a family and run a restaurant at the same time.  I’m glad we had a chance to say thank you.

The last day for the Night Kitchen is November 3rd.

That is the title of an opinion piece that appeared in the Montreal Gazette on Thursday August 29, 2013.   This article was in response to a current news story in Quebec regarding the discovery of PCB waste and transformers that were being stored illegally.  The author, “Dr. Joe” Schwarcz is  a well regarded chemistry professor at McGill University.  If you take the time to read his opinions on PCBs (highly recommended), you will find they provide an interesting perspective.

The PCB regulations (40 CFR 761) were proposed by the USEPA to implement some of the  specific the requirements in the 1976 Toxic Substance Control Act (TSCA).  While only a small part of TSCA, the PCB mandates (Section 6(e)) looms large in the regulatory world.  Yet a closer look at the history of the TSCA reveals that the the PCB program was more an accident of chance rather than a carefully conceived Congressional initiative.  If you want to learn more about how this particular “sausage” was made, then read on.

The Roots of TSCA

President Richard Nixon (possibly the most pro-environmental president since Teddy Roosevelt) first proposed the Toxic Substance Control Act (TSCA) to the 92nd Congress in 1971 .  The President’s Council on Environmental Quality (CEQ) had crafted the initial TSCA bill over the previous year; coincidentally, the same year that the USEPA itself came into being (1970).  In CEQ’s 1971 report titled Toxic Substances, the the Council argued that the government needed additional legal authorities to regulate toxic substances in commerce to meet the larger goal of protecting public health and the environment.  Here is a summary of the CEQ’s principal arguments for the passage of TSCA:

  1. Toxic substances are entering the environment.  Over 9 million chemicals are known with several thousand new ones added each year.  Although many of these are not toxic, the sheer number of them and the evidence of toxic incidents that have already occurred indicate the nature of the problem.
  2. These substances can have severe effects.  The report describes the range of possible toxic effects in general terms that we are all now familiar with.
  3. Existing legal authorities are inadequate.   The report describes the principal environmental legislation as being media based – the then Federal Water Pollution Control Act for waste water, the Clean Air Act for air pollution etc.  CEQ indicated there was a need for legislation that cut across media and focused directly on potential toxic pollutants.

While the US Senate found the arguments for TSCA persuasive, the House of Representatives did not.  As a result, TSCA languished through the 92nd and 93rd Congresses; the House majority believed TSCA placed unreasonable burdens on industry, particularly the chemical industry.  Recall that the period from 1973 to 1975 was one of severe economic recession; there was little national appetite for adding to the regulatory burden on an already depressed industrial sector.

The Resurgence of US Environmentalism

But the 1960s and ’70s were also periods of rapid growth for the environmental movement.  Pressure was increasing for government to play a larger role in protecting human health and the environment; environmental groups were calling on Congress to do more.  Washington was under siege for action on both the economy and the environment. Given the conflicting interests Congress did what it often does best, nothing.  Meanwhile the draft TSCA legislation collected dust.

Kepone and the Environmental Tipping Point

Meanwhile a tragic series of mishaps at a small pesticide manufacturing plant on the banks of the James River in Hopewell, Virginia was about to grab the national spotlight and indirectly become responsible for the passage of TSCA.     Allied Chemical Company (which subsequently became AlliedSignal) had a manufacturing plant in Hopewell that produced a small volume pesticide named Kepone (aka chlordecone).  In 1973 the overseas demand for Kepone began to increase and rather than expanding its own production facilities to meet this demand, Allied leased the Kepone production rights to two of its Hopewell employees.  These employees started a new business called Life Science Products (LSP) and in 1973 they began production of Kepone in a renovated former Hopewell service station.

Kepone is a member of the chemical group called “chlorinated pesticides”.  This group also includes other more well known insecticides like DDT, chlordane and heptachlor.  Since the 1970s, the use of almost all of these chlorinated pesticides has been banned in the US and abroad.   The chemical structure of Kepone is complex and unlike any naturally occurring substance.  As a result, Kepone is resists natural degradation and is persistent in the environment.  Also like other chlorinated pesticides it bio-concentrates up the food chain.  However, unlike some other chlorinated pesticides, it can be very toxic to people.

LSP’s attention to employee safety and house keeping practices were somewhere between lax and downright sloppy.  There are newspaper accounts of Kepone powder blowing like snow in the wind and forming dunes on and off of the plant’s property.  The adverse health effects caused by Kepone exposures began to surface when LSP’s employees started exhibiting the severe neurological symptoms indicative of Kepone poisoning. Ultimately 30 LSP employees were hospitalized and more than 50 were seriously poisoned.  Testing of other exposed people  in Hopewell (mostly family members of employees) identified that more than 200 had Kepone body burdens higher than was considered safe.  Ultimately the problems drew the attention of the federal government.

Quoting from one incident report:

“CDC (Center for Disease Control) investigators inspected the LSP facility and were appalled to find Kepone everywhere. One CDC epidemiologist reported that, “…there were 3 to 4 inches of the material on the ground…There was a 1 to 2 inch layer of Kepone dust encrusting everything in the plant.” Analyses of the air within the plant indicated that the employees inhaled 30,000 μg of Kepone per day. This stands in contrast to the federal government acceptable limit of 10 μg/day.”

However, even this report did not capture the full extent of the problem as it was estimated that 10-20 tons of Kepone had been discharged directly to the James River.  The river ecosystem was devastated with significant impacts to birds, fish and other wildlife.  The entire previously productive fishery between Hopewell and the Chesapeake Bay (100 river miles) was for years out of health concerns and 4,000 people involved in the James River fishery lost their jobs.   The fishery was not reopened until decades later after clean sediments finally buried the Kepone under a thick layer of silty mud.

The Kepone incident received broad national attention.  Dan Rather and the 60 Minute investigative team did a long segment on Kepone and the Hopewell plant.  There were clips of Dan Rather on the roof of LSP’s building pushing around mounds of Kepone dust.  Kepone was also the lead story in Time magazine.  The governors of Virginia and Maryland demanded that the recently formed USEPA conduct a federal investigation and several Congressional hearings were held.

Kepone’s Political Fallout

The Kepone incident pushed public sentiment well passed the tipping point on the issue of toxic substances regulation; the uproar and resulting political pressure overcame the House of Representative’s resistance to the passage of TSCA.  In 1976, after a five year wait, TSCA was finally passed by large majorities in both the Senate and the House.  President Gerald Ford signed the bill into law.


The original 1970 version of TSCA authored by the Council on Environmental Quality and submitted to Congress in 1971 did not contain the provision directing EPA to regulate PCBs (aka Section 6(e)); it did not mention PCBs at all.  Section 6(e) first appeared as an amendment to the 1975 Senate bill and  there was strong advocacy in favor of it by environmental groups and labor unions.  But, the Senate rejected the amendment because the majority considered the 6 (e) language to be too technically specific for inclusion in the Act and because the USEPA Administrator, Russell Train, argued strongly against its inclusion.

However, despite this earlier rejection, section 6(e) was re-proposed as an amendment to the Senate’s 1976 TSCA bill by Senator Gaylord Nelson of Wisconsin.  Nelson correctly sensed that, as a result of the Kepone incident, the political ground had shifted and the time was now right to get TSCA passed with section 6(e).  With the maelstrom of Kepone publicity swirling around, Nelson’s amendment was accepted into the Senate bill without resistance on the last day of debate. 

Meanwhile, Representative John Dingell of Michigan offered Section 6(e) as an amendment to the House TSCA bill.  Unlike in the Senate, there was spirited opposition to the amendment in the House.  However, even in the House, public outrage over the Kepone incident trumped all other considerations in the representative’s minds.  The amendment was quickly adopted and the bill moved on to President Ford’s desk with Section 6(e) intact.  Thus was born the PCB regulations.

With all the writing I do about serious environmental and regulatory issues, this seemed like a good time to switch focus and write instead about the more enjoyable side of the environment.  So today’s topic is three of my very favorite Massachusetts places: Bartholomew’s Cobble in Sheffield; Laughing Brook in Hampden; and 40 Steps in Nahant.  Each of these is a gem, but they are very different from each other.

Bartholomew’s Cobble – This 329 acre property, owned by the Trustees of the Reservations, is tucked into the southwestern corner of Massachusetts with Connecticut just to the south and New York state to the west.  We visit most falls during foliage season starting off at the small headquarters building, walking down the forest trail by the Housatonic River and finally heading up a steep trail to the top of the 1,000 foot elevation Hurlburt’s Hill for the spectacular view north into the Berkshires.

The property is named for the heavily weathered marble and quartzite boulders found along the trail paralleling the river.  The erosion of these boulders has caused the soil in the area to be atypically alkaline (most New England soils are acidic to neutral), as a result the area supports a large and rare assortment of wild plants, particularly ferns.  The variety of ecological niches present and the interesting history of the property make it a great day trip destination.

One warning: the mosquitoes can detract from a visit if they are out in force; that and the great foliage are why we opt for a visit in the fall after the first frost.

Laughing BrookLaughing Brook is a Mass Audubon Wildlife Sanctuary that is classic central New England hardwood forest land.   The 353 acre property includes a pond, Laughing Brook and wetland areas in addition to the upland forest.    At one time the sanctuary included a beautiful educational center, but it was sadly lost to a fire.

There is a 4-mile trail system in the sanctuary, which connects to other trails that meander through the Hampden Hills for quite a distance, and that goes by interesting stone outcrops and on top of an excellent example of an esker. 

Laughing Brook lacks dramatic views, but it is a great spot for a family trip and for introducing children to the joys of walking in the woods.  It is also a super spot for cross country skiing when the snow is right.

40 Steps – As painful as driving the Lynnway can be (its an urban traffic artery running north of Boston), I am thankful that it does limit the number of vehicles that make it to Nahant.  However, if you enjoy environmental settings like the rocky coast of Maine, then it may be worth fighting the Lynnway traffic to make a half-day trip to 40 Steps Beach on Nahant.

If you look at a map of Boston Harbor the furthest north land mass is likely to be Logan Airport or possibly Winthrop, a city located on an island just north of the airport.  However if you go further north up the coast, just past the City of Lynn, you will see the small town of Nahant located on two small islands.  The islands (known as little and big Nahant) are connected to the mainland by a causeway; 40 Steps is the name of a sand and stone covered beach on the eastern side of big Nahant.  There is no legal parking nearby and to get to the beach you need to walk down a set of winding stairs.  At one time there were about 40 rickety wooden steps leading down to the beach, and that’s where the name came from.

As difficult as it is to get there, 40 Steps (scroll down to the 4th photo on the linked web page) is a very special spot.  It is not really a good beach for kids; it’s an adult beach.  Not that there is anything untoward going-on (at least not when I have been there), but it’s a meditative setting for reading a book, watching the waves crashing on the rocks and just relaxing.  Not a lot for kids to do except to ask when it will be time to leave.

If you visit any of these special places I hope you enjoy them as much as I have.

On Wednesday May 8th, the Hadley Falls Fish Lift is scheduled to open for the spring fish migration.  The lift provides a unique opportunity for visitors to see one of nature’s truly amazing sights with their own eyes; the annual migration of anadromous fish up the Connecticut River.  The lift is operated and maintained by HG&E (Holyoke Gas and Eclectic) which operates the Hadley Falls Dam. A visit makes a great field trip for children and adults.

Admission is free, but the viewing season ends in mid-June, so don’t wait too long to go.  Highly recommended.

Before beginning this post we at OTO want to express our deepest sympathies to the individuals and families who experienced losses in the wake of the horrible Boston Marathon bombing.  We also want to extend our gratitude to the medical teams that helped the injured and to our local, state and federal law enforcement officers who worked tirelessly to bring order back to the Commonwealth.

PCBs in Soil around Buildings

One of the questions that often come up after soil is tested for PCBs in the vicinity of a building is: why are there higher concentrations of PCBs in the soil right around building foundations?  There has been a tendency for investigators to shrug their shoulders and answer: it must be from the degradation of PCB containing caulk or paint used on the outside of the building.  Frequently there is no direct evidence to support this claim, but it seems like the only reasonable explanation that is consistent with the findings.  Well here is another explanation that might also make sense. 

PCBs in Pesticide Formulations

In the 1950s and ‘60s it was common to treat the soil volume immediately around building foundations with pesticides to control or prevent infestations of soil dwelling insects (like termites, ants etc.).  Solutions of pesticides were pumped into the ground under pressure until the surface soil became wetted.  Among the pesticides commonly used in this way were lindane and several of the other chlorinated pesticides.  Since the chlorinated pesticides were very effective and more persistent in the subsurface environment than other options, they were often the pesticide of choice for this purpose.

Although pesticide registrations are now overseen by the USEPA, before there was an EPA (pre-1970) it was handled by the US Department of Agriculture (USDA).  The USDA has generally had a more “congenial” relationship with farmers and other agricultural enterprises than the EPA has had with farmers and the rest of US industry.  During the period when USDA regulated pesticides it was not out of the ordinary for the USDA to make recommendations on the more effective use of pesticides including pesticides for the control of soil dwelling insects.

One of the ways that pesticides lose their potency (even in the ground) is through the volatilization of the active component into air and via the solublization of the  pesticide into water percolating through the soil.   USDA researchers discovered that the addition of certain oils and/or chemicals to a pesticide formulation prior to its application could inhibit the volatilization and solublization of pesticides thereby increasing the amount of time a single application would remain effective.  Further, it was discovered that one of the very best additives for extending the useful duration of a pesticide applications was polychlorinated biphenyls (PCBs).  PCBs did not modify the pesticide’s mode of toxic action, but they did extend the effective duration of a pesticide application up to ten times over a control application that contained no such additive.

This meant that the addition of a relatively small amount of PCBs to a pesticide formulation could significantly increase the value of a single application.  This obviously presented a significant economic incentive for the inclusion of PCBs into pesticide formulations.  The use of PCBs in this manner was actually encouraged by the USDA because it reduced the total amount of pesticide required to control insects in any given situation.

All that Remains

The last pesticide application that included PCBs likely occurred more than 40 years ago.

While it is possible that some detectable trace of the active pesticide ingredient still remains where it was applied, it is more likely that simple volatilization and the aggressive soil biochemical environment has attenuated the pesticide concentrations so they are too low to measure.  However, it is likely that the PCBs used in that long ago application are still present in the soil and can still be readily measured.

For help understanding how PCBs entered soil at a property please contact me at

In a regulatory reinterpretation with far significant implications, the USEPA clarified the definition of “Excluded PCB Products” as used in the PCB regulations and signaled its intention to deemphasize the regulation of low concentration PCBs in commercial products.  Excluded PCB products are defined as commercial products containing PCBs originating from Aroclor or non-Aroclor sources where the PCBs are present at less than 50 ppm.

The excluded product reinterpretation was the result of a request by the Institute of Scrap and Recycling Industries, Inc. (ISRI) which was seeking clarification on the management of plastic residue from automobile shredding and recycling.  This plastic residue sometimes contains low levels (less than 50 ppm) PCBs.  Managing the material as a PCB remediation waste limited the recycling industry’s ability to reuse this plastic and increased the cost of the recycling operations.  If it was clearly understood to be an excluded product, then the regulatory burden would be less.

There is often confusion about whether a PCB containing product with less than 50 ppm PCBs should be classified as an Excluded PCB Product or as a PCB Remediation Waste.  The responsibility for making this decision rests with the waste generator, but complicating the assessment is the sometimes variable guidance between EPA regions.   Remediation waste must be managed in accordance with regulatory requirements, excluded product waste is effectively deregulated.  For generators the differences in the management costs and potential long term liabilities between the classifications can be large.

The reinterpretation establishes guidance from EPA headquarters that should assist generators in making the decision.  EPA restated its policy that most materials containing less than 50 ppm PCB are not regulated by the PCB regulations.  The reinterpretation also seems to lessen the burden of proof for generators who claim their material should be classified as an excluded product.  Here is a key quote from the reinterpretation:

“In promulgating the excluded PCB product rule, EPA described the provision as follows:

“EPA is adopting the generic 50 ppm exclusion for the processing, distribution in commerce, and use, based on the Agency’s determination that the use, processing, and distribution in commerce of products with less than 50 ppm PCB concentration will not generally present an unreasonable risk of injury to health or the environment. EPA could not possibly identify and assess the potential exposures from all the products which may be contaminated with PCBs at less than 50 ppm. . . . EPA has concluded that the costs associated with the strict prohibition on PCB activities are large and outweigh the risks posed by these activities. 53 FR 24210 (June 27, 1988).

“EPA has further stated, with respect to the excluded PCB products rule: “These amendments have excluded the majority of low-level PCB activities (less than 50 ppm) from regulation” (Ref. 4). Given the difficulty of determining the precise source of PCBs, EPA believes the purpose of excluding “old” PCBs under the excluded products rule is best effectuated in these circumstances by treating < 50 ppm materials entering a shredder as excluded PCB products unless there is information specifically indicating that the materials do not qualify”.

The reference to the “excluded PCB product rule” refers to a 1988 PCB regulation amendment that confirmed EPA’s intention to not regulate most PCBs at concentrations less than 50 ppm.  The history behind he excluded product rule is a story unto itself (maybe for another post).

Over the past few years the relevance of the 1988 excluded product rule has been cast in some doubt.  However, with this new interpretation EPA has affirmed its decision to not regulate most PCBs at concentrations less than 50 ppm and has clearly reiterated its long standing position “that the use, processing, and distribution in commerce of products with less than 50 ppm PCB concentration will not generally present an unreasonable risk of injury to health or the environment”.

For help with PCB waste classifications please contact Jim Okun at

From a professional perspective, PCBs entered my life in 1978 while I was post-grad research associate at the U of Hawaii College of Tropical Agriculture.  The mission of our lab was to develop data in support of EPA pesticide registrations for tropical crops.  Pesticide registration is normally conducted by the pesticide manufacturers, but tropical crops are such a small niche market, that it isn’t worth their trouble in most cases.

One day the lab director brought a box with ten 8-ounce jars into my work area and put them down on my lab bench (tangential comment – this is the work area from which I had a view of three waterfalls, sigh).  He told me each of the jars contained a different Aroclor PCB mixture and that the Hawaiian electric company wanted us to develop an analytical method to measure the amount of PCBs in transformer mineral oil.  For the next couple of months, while working up the analytical method, these jars were front and center on my lab bench.  These were not laboratory prepared analytical standards; these were jars containing pure (“neat” to you chemists) Aroclors.

As a young chemist the opportunity to work on an environmentally relevant project was a real thrill.  As you likely know, the percent of chlorine in an Aroclor is indicated by the last 2 digits in the model number; so Aroclor 1221 contains 21% chlorine by mass and Aroclor 1268 contains 68% chlorine (Note: this numbering does not apply to Aroclor 1016 which is a modified version of Aroclor 1242 and thus contains 42% chlorine).  The lighter Aroclors like 1221 and 1232 were as thin as machine oil.  The mid weight Aroclors (1248 and 1254) were as viscous as motor oil.  Aroclor 1268 was pretty much a solid at room temperature.  Also, the lighter Aroclors were clear and the heavier ones had a darker quality to them.

On the chemistry side, there are 209 different PCB molecules (called “congeners”), and each of the Aroclors is a mixture of 50 or more of these congeners.  Chemists sometimes organize the different congeners into groups based on the number of chlorine atoms they have and these groupings are called “homologs”.  So for instance, all the different congeners that have three chlorines belong to the tri-chloro homolog group, all the congeners with four chlorines belong to the tetra-chloro homolog group, and so on.

There is an interesting difference among the Aroclors (interesting to me at least) that even many chemists are not aware of; each Aroclor PCB mixture is dominated by a different homolog group.  So for instance, Aroclor 1221 is made up of 60% mono-chloro congeners (one chlorine), Aroclor 1248 is 56% tetra-chloro congeners (four chlorines), and Aroclor 1262 is 47% hepta-chloro congeners (seven chlorines).  This formulation was not created by design; it was just an accident of the manufacturing process.

Meanwhile back at my lab at the U of H, and many, many gas chromatographic runs later, I did finally come up with a reliable method for measuring PCBs in transformer oil.  Remember this was before there was an SW-846 (EPA’s compendium of analytical methods) or a Method 8082 (EPA’s PCB analytical method).  The method I developed for measuring PCBs in transformer oils was actually published in the Journal of Chromatography (JOC) and the article can still be obtained on-line (the link is for the curious, but purchase is not recommended since this method has been superseded by better USEPA analytical procedures).

When I looked up the link to the JOC article to include with this post I was disappointed to see that the U of H College of Tropical Agriculture now has a trendier name, the “Department of Agricultural Biochemistry”.  On the other hand, I was very pleased that when I clicked my name on the author list my address came up as “University of Hawaii, 1800 East-West Road, Honolulu, Hawaii”;  on a cold windy late winter day it’s nice to still have an address in Hawaii.

In closing, let me acknowledge Dr. James Ogata who directed my work at the U of H lab and who prepared the manuscript for publication.

For help with PCB chemistry questions, please contact me at