First published in Mushroom, The Journal Issue 26, Vol.8, No.1 Winter 1989-90 p5-8. Parts also appeared in newsletters of COMA and MHMA.

Since articles appearing in MTJ are not digitized, and since the problems of assessing the toxicity of morels collected from contaminated areas such as apple orchards, roadsides, and railroads has recently reemerged as a subject of interest, this article is being posted here for public accessibility and reference.



Some secrets are arrogant, living with a special tension, surviving on the thin line between the known and unknown, thrilling us with the slipperiness of a tie which holds together that which needs release.  The more, it seems, we fondle the knot, the looser it becomes, and so, by design, we reveal that which we intend to conceal.  It was in this manner that one of the greatest Morel hunters around revealed to me the location of one of his favorite patches.

He lives in New York City but makes frequent forays into our area in the spring searching out mushrooms.  Bit by bit his pride at finding a great location "under our very noses" pried loose the secret.  "On the west side of the river", he said, "on a major road … just over the county line… an abandoned apple orchard… on both sides of the road…. poison ivy out the gazoo, but Morels galore."  He showed photographs to prove the point; Great shots of twenty or thirty big blonde Morels trooping around the base of an apple tree, with more trees and mushrooms fading into the background.

He said he would never tell anyone where it was, but already I knew the precise location, for every spring in late May and early June I make several trips to the East Branch of the Delaware River to fish for Shad, and on the way, just across the county line an abandoned apple orchard spills across the road and floods my mind with thoughts of mushrooms.  I think of nothing else for the next ten miles and keep reminding myself that "next year" I should come a few weeks earlier and look for morels.

Last spring I did. I had a spring mushroom identification course in Mid-May at the Arboretum and used that as an excuse to search out new sites for field trips.  And so it was that Pete Katsaros and I found ourselves poking around in the Poison Ivy of an abandoned apple orchard one weekend late in April.

The day was cool but bright. The trees were not yet in full leaf and the brightness of the noonday sun cut through their skimpy canopy with ease, causing us to squint and to walk with the sun at our backs.  Because of the sun the Morels were not easy to see but they were there. The Black ones were the most prevalent, but here and there was a tree ringed with small Blondes.  They seemed to occur in patches, a group here, a group there, usually around the sickliest of the trees.

We were so intent on our search that we failed to notice the owner of the orchard when he showed up.  His large four-wheel vehicle appeared suddenly, jerking us both from our reverie.  A shotgun hung on the gun rack behind his head, and what turned out to be a .357 Magnum lay exposed on the seat beside him.  Static from his radio transmitter punctuated the silence and an eerie tension filled the air.  I had a sudden desperate yearning to be fishing the Delaware even though the Shad were a month downstream.

He was not an old man, middle aged at best, and yet he spoke as if he had understudied an older, southern Clint Eastwood.  "What you Boys lookin' for?", he asked.  "My Mama saw you two creepin' around here and called me right away."  He jerked his head over his left shoulder commanding us by that gesture to look thataway. Sure enough in the middle of the hillside orchard across the road was a house and there in front of an open door was an older woman whom we took immediately to be Mama.  She was watching us through a pair of binoculars.  "She seen your every move", he said. What's the matter, you can't read the 'No Trespassing' signs?"

No, we allowed, we could read the signs, but there were so few, and so old and tattered, and we didn't know where to go to ask for permission and we were just two naturalists  out walking and looking at what the spring was bringing to this orchard, and that seemed harmless enough, and we were sorry to bother him and cause his mother to worry, and we were glad to see him and know that he was as interested in the land as we were, and we would be more than happy to leave right this minute and never come back, and…

Just then a Hawk circling overhead issued a thin whistle.  We all looked up. "Red Tail" said the man in the truck. "Yes", said Peter, "Buteo jamaicensis".  "Oh! You two birders?" he asked with a distinctly softer tone to his voice. "Why didn't you say so before?"  And the talk turned to birds, and voles, and a den of Red Foxes on the other side of the stream. And of hunters and trespassers, and DEC and toxic waste and how it was that he got out of the apple business.

Trucks, he said, would pull up in the middle of the night, just ease in off the main road onto his work lanes in the orchard and here and there dump all manner of stuff around.  That’s why all of those trees were so sickly.  His father, an Italian, thought the Mafia had something to do with it.  The DEC closed down the orchard and the father died shortly thereafter. Now here he is with a poisoned apple orchard.  He could sell the land for a housing development but would rather keep it for the Foxes.

I was almost afraid to ask him if he could remember exactly where some of the dump sites were, but I did, and he pointed out how you could tell the asbestos dumps by the mounds they made, and how some of the chemicals with the wretched names and reputations had caused the trees to get sick and die.  He pointed to several places here and there around the orchard, and they were in many cases the very places we had found the Morels.

We ate none of these Morels and declined to return, even though invited.  But I thought of the Buddha several times that spring as I passed on my way to the Delaware. The secret of desire, he said, is to release it. You can have anything in the world you want. The trick is not to want it.


As luck would have it, I encountered a second association of morels and toxic chemicals a few weeks later when I brought the mushroom identification class on a field trip to our environmental education center which is located on the banks of the Hudson River.  The deep rich soils here support a broad range of vascular plants and a wide assortment of fungi.  Morels are reliably found every spring, and with them members of the Mid-Hudson Mycological Association.

For years some of us have been aware of the proclivity of morels for fruiting along railroad tracks and power lines but have avoided collecting in these areas which are obviously contaminated with a host of chemicals deliberately or accidentally dumped, sprayed or jettisoned along these corridors.

In places oil covers the ground, empty drums and canisters used as 'fill' push up through the barren grade and the sun which beats down on the black ashy coal cinders releases the characteristically acrid odor of unregulated heavy industry.

The area is so esthetically unappealing that it had remained unexplored, out of sight and out of mind. The few collectors who knew of the morels there chose not to advertise their presence to a wider audience for both selfish and altruistic reasons.

All of this changed last spring (1988) when an exceptionally rich fruiting of morels on the railroad tracks revealed itself to one sharp-eyed member of our mycological club whose bushel of morels was shown to other members of the club and to the mushroom identification class which was also collecting in the vicinity. The cat was out of the bag and 50 or so collectors were primed to return for their bushels full too!

What to do?  I spoke with N.Y. State Mycologist Dr. John Haines about the situation. He was able to verify that Amtrak conducts semi-annual spraying of the tracks through Railroad Weed Control (out of Springfield Conn.)  The springtime spraying of Atrizol and Diuron (Carmex) is done in May at the peak of the morel season to inhibit seed germination and photosynthesis of green leafy plants.  A fall series of Roundup (Glyphosate) and Weedar (2,4-D) is used for later emerging, more woody plants.

Two concerns immediately presented themselves to us.  Any morels in the path of the spray were likely to be contaminated by the spring spraying, particularly if they had emerged prior to the application of herbicide, and considering their morphology they would be nearly impossible to rinse.

Secondly, there was also the possibility that even if the mushrooms were picked prior to the spraying they might still be contaminated from residual pesticides of either the spring or fall series which might be transported from the ground through the mycelium to the fruiting body.  We therefore thought it prudent to warn the mushroom collectors immediately of these potential dangers.

There was also a third more academic interest.  Why, we wondered, was there the prolific fruiting of morels where spraying had occurred?

Was this connection due to the magnitude of dead or dying vegetation which somehow released special nutrients to the fungus, to the relative lack of competition for resources from vascular plants, or was there something about the chemicals themselves which tended to stimulate fungal growth?

We felt the toxicity issue needed to be addressed immediately and first considered a public health alert through the local press and radio stations, but decided in favor of a more discrete notice to both of the groups actively collecting in the area.

Members of the mushroom identification class were notified of the potential dangers of eating these mushrooms by the Institute of Ecosystems Studies, and an emergency telephone chain was initiated to members of our regional mycological society.

I returned to the area and made a fresh collection of several pecks of morels.  All were collected within several yards of the tracks within a clearly delimited area of dead vegetation.  The area beyond which showed the normal springtime flush of green had only the occasional morel.

Systematic collections of morels above, below, and on grade were brought to Albany where Dr, Haines arranged to have them analyzed both for the pesticides listed and also for lead and cadmium.  Testing for heavy metals seemed prudent since heavy metals are rapidly and easily absorbed and transported by fungi, and the soils of the railroad grade seem particularly likely to have been contaminated.

A review of the literature showed a quite complex picture, with no clear answers for this inquiry.  These herbicides are widely used for weed control because their toxicity levels are all considered 'low'.  If their dangers are to be measured by the amount of ingested chemical needed to kill half of the rats used in laboratory tests, then indeed these synthetic compounds are much safer than some of the older organic compounds which generations of gardeners have used, and also safer than many other garden chemicals in common use, as the following figures will show.

(Amount of each pesticide needed to kill half of the rats: LD50)

Triazines (Atrizol)300-5,000 mg/kg

2,4-D (Weedar)300-1,000 mg/kg

Glyphosate (Roundup)4,000  mg/kg

Diuron (Carmex)1,500-11,000 mg/kg

Nicotine30 mg/kg

Pyrethrum820 mg/kg

Rotenone132 mg/kg

DDT200 mg/kg

Sevin307 mg/kg

Parathion10 mg/kg

Copper Sulfate300 mg/kg

Pentachlorophene210 mg/kg

But simple "50 percent mortality rates" for rats in laboratories do not tell the entire story, for often there are delayed effects of sub-lethal doses, some not appearing for 20 or 30 years or more.  By now we are all aware of the lingering effects of minute amounts of DDT and its metabolites which are carcinogenic at a few parts per million.

Dioxins, the inevitable contaminants of the 2,4-D family of herbicides (Phenoxy alkanoic acids), have been called "among the most biologically active compounds known", dangerous at a few parts per trillion!  Accordingly, the acceptable level of 2,4-D in foodstuffs has been set in the order of a few parts per million.

Furthermore, pesticides such as DDT and 2,4-D compounds, built around a carbon ring, actually accumulate in magnitude as they move their way through the food chain. (One study showed levels of 2,4-D in the water at 0.1 part per million, yet accumulating to 18 parts per million in the flesh of oysters in only seven days.)

Fortunately the very nature of the "organic" carbon ring of 2,4-D also allows for rapid decomposition in the soil by microbial decay and fungal attack, and it is generally assumed that unless highly chlorinated, the phenoxy alkanoic acids will degrade within a month or so.

The triazine family of pesticides, on the other hand, is built around a nitrogen ring.  As such, the family is specifically designed not to mimic carbon based organic molecules and therefore is not likely to enter the food chain or to be subject to biological magnification.

Since these triazines escape organic mimicry, they rely heavily upon ultra-violet radiation to break them down.  When applied in a water based suspension however they quickly percolate into the soil and become impervious to ultra-violet degradation. They end up being relatively long-lived compounds underground where they are known to undergo complex and substantial reorganization of the radicals attached to the central nitrogen ring. (Levels of acceptable toxicity again are in the few parts per million ranges.)

Some of the literature also revealed other unexpected factors.  In order to improve the delivery of herbicides, for example, they are often applied in an oil, rather than water-based spray, and because of economy, drain oil and used transformer oils often have been used in the past, particularly on railroad grades and along power lines.

This practice has largely been curtailed because of the well-documented health hazards of these compounds, but the health hazards remain behind in the backwash of their use.  PCB's for example, the polychlorinated hydrocarbons used in transformer oil,  have the same carcinogenic characteristics as DDT, are exceptionally long-lived and are readily subject to biological magnification.  Once applied to the land they can be expected to contaminate for decades!

Literature on the effects of herbicides upon fungi was particularly hard to come by.  A computerized search of worldwide biological abstracts, done by Ron Crovisier of the Mid-Hudson Mycological Association, was able to locate a dozen or so recent studies involving triazine and 2,4-D interactions with fungi. All of the studies located by this process were conducted in Europe.

In Poland the emergence of Morchella semilibra on paths sprayed with herbicides has been documented, and a study conducted in the USSR demonstrated that the triazines do interact with lower fungi (e.g.Aspergillus and Pennicillium) grown in pure culture.

The interaction is complex.  At low levels of concentration fungal growth is stimulated, at higher levels it is retarded, and at all levels the compounds undergo transformation by the fungi.

This tends to support the hypothesis that herbicidal spraying might stimulate fungal growth, but leaves unanswered the questions of transport and accumulations of triazine residual compounds within the fruiting body.

The European literature, however, is quite clear that the 2,4-D compounds are often found in wild mushrooms, that they are persistent, and that they often appear in (or accumulate to) highly toxic levels.

One Swedish study found the residues lasting for over two years, at levels that were "moderately high" in the mushrooms although nearly insignificant (less that .01 part per million) in groundwater.

Another Swedish study found "relatively high" levels in mushrooms collected immediately after spraying and one month later.  This study also found that "up to 40 percent of the residue in mushrooms was removed by rinsing, regardless of the sampling time" and that up to 60 percent of the residue could be removed by parboiling.

A West German study put it quite bluntly: "The unexpectedly high residual concentrations of slowly degraded herbicides present an acute danger to humans gathering berries and mushrooms."

It would appear that Amtrak and Railroad Weed Control might concur, for they forbid any foraging on the railroad right of way.  And although they have not thought much about mushrooms, they are quite worried about the health hazards of berries which grow along the tracks.


The tests on the morels brought to Albany were conducted by the State of New York's Department of Agriculture and Markets in July and came back negative for Atrazine, Diuron, Monuron, and 2,4-D.  Although requested, a test for Glyphosate (Roundup) was apparently not conducted.  Dr. Haines has been unable, to date, to find a sponsor for the heavy metal tests.

The lack of any detectable levels of these pesticides in the morels sampled left us feeling guarded relief.  It may mean that these pesticides are nottransported through the mycelium to the fruiting body.  This appears to be a reasonable hypothesis with regard to 2,4-D, which was applied in the fall yet failed to be detected in the spring morels.

The lack of any levels of the spring series (Atrazine, Diuron) probably means these morels were picked prior to the spring treatment on this section of the track, for it seems highly unlikely that mushrooms actually sprayed would be totally absent of any detectable levels of either compound.  It seems prudent to assume that if sprayed, the compounds would appear on the surface and within the pits and tissue of the mushroom, and would probably present a health hazard.

A personal anecdote might be helpful here.  A few years ago my home vegetable patch received an unintended treatment of atrazine and cyanazine when the spray "drifted" onto my property from a neighbor's corn field, pushed by a 25 mph warm southerly wind.  Among other things our strawberry patch was visibly dampened by the spray.

In trying to find the answers to some of my concerns about using the garden I was led to the then-senior specialist at Cornell University who gave me his advice about the strawberries.

Eat them, he said, only if you are old and only after they had beenpeeled! In no way would he recommend the sprayed berries to anyone who hoped to live for another few decades because the long-term effects were simply unknown.  This seems to be good advice for mushrooms as well.

So, should you collect these morels found along the railroad tracks, roadsides, and apple orchards treated with herbicides?

This might be a case where those of us who are Old and Bold will seek the pot, those Gray and Wise ones will seek Satori, and all who are Still Young will be left to wrestle with the temptations of spring and the advice of our elders.

The morels are there.  To eat or not to eat? That is the question.  For my part, I'll pray to the Buddha and fish for shad.

REFERENCES: Reconstructed from my notes: These were not included in the original publication, but my files show interest from academic researchers asking for these sources in the months following publication.

Library sources:

McEwen, Use and signifance of pesticided in the environment. 632.95 M142

Pimental, Ecological Effects of Pesticides on nontarget species. 632.95042 (p644)

BRS BIOSIS (selected from computer search by Ron Crovisier, Research Librarian, Dutchess Community College)

Kardell L. Forest berries and mushrooms – an endangeres resource?  Ambio 9(5):241-247 1980

Toth B. Actual new cancer-causing hydrazines, hydrazides, and hydrazones. J Cancer Res Clin Oncol: VOL 97, ISS 2, 1980 p97-108

Moeschlin S. Currently occurung toxic accidents. Z. Allo. Med. 55(5) 269-276 1979

Siltanen H : Rosenberg C Analysis of 2,40D and 2,4,5-T in logonberries, wild mushrooms, birch and aspen foliage. Bull. Environ. Contam. Toxicol. 19(2): 177-182 1978

Wellenstein G Biological and eco-toxicological problems regarding aerial application of phenoxyacetic acid derivatives in forests.  Qual. Plant. Pl. Foods Hum. Nutr. 25(1):1-20 1975

Wellenstein G  Inadmissably high pesticide residues in berries found in forests. Umschau Wiss. Tech. 75(16): 510-512 1975

Erne K Weed-kilers and wildlife_some recent results. Z. Jagdwissenschaft 20(1): 68-70 1974

Erne K : Haartman Uvon  Phenoxy herbicide residues in woodland berries and mushrooms. Var. Foeda25 (8-9): 146-154 1973 (REF:8))

Manturovskava NV  The effects of symmetrical triazines on mushrooms in pure cultures. Vest. Mosk. Univ. Biol. Pochvoved.: 25(3): 31-36 1970

Turnau-K.  An emergence of Morchell-semilibera Dc. Fr. after application of Gsaprim 50.  Zesz. Nauk. Uniw. Jagiellonsk Pr. Bot. 0 (15), 1987. 153-158

Interviews with Soil Scientists Richard Kruzansky, Cary Arboretum, Institute of Ecosystems Studies and Rob Dibble, USDA Soil and Water specialist, Millbrook NY

Testing of Morels was conducted  by State of New York, Department of Agriculture and Markets FL_056201 inspector 914  delivered 5/20/88. analysis code method 08 "probably gas chromatography or atomic absorption" 

An edited version of this article can be found at