FROGS IN AN EFFLUENT SOCIETYRisks, Remedies and Responsibilitiesby Dr Sara Broomhall

First published in June 2004 by WWF Australia© WWF Australia 2004. All Rights Reserved.ISBN: 1 875941 67 3

Author: Dr Sara Broomhall

WWF AustraliaGPO Box 528Sydney NSW AustraliaTel: +612 9281 5515Fax: +612 9281 1060www.wwf.org.au

For copies of this booklet or a full list of WWFAustralia publications on a wide range ofconservation issues, please contact us onpublications@wwf.org.au or call 1800 032 551.

The opinions expressed in this publication arethose of the authors and do not necessarilyreflect the views of WWF.

Special thanks to Craig Cleeland for supplyingthe photographs for this booklet.

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CONTENTS

FROGS AS ENVIRONMENTAL BAROMETERS

What is a pollutant? 2

Australian frogs 2

How do frogs interact with their environment? 3– Life stages 3– Habitat requirements 3– Ecological position 3– Frogs and pollutants in the food chain 3

Why is environmental pollution a frog issue? 3– Are frogs more sensitive to environmental

pollutants than other species? 3

WHAT WE DO AND DON’T KNOW

Why don’t we have all the answers? 4– How relevant are these toxicity tests

to real world situations anyway? 4

Where do pollutants come from? 4

How many chemicals do we use here in Australia? 4

Who produces pollutants? 4

WHAT’S HAPPENING?

So how am I polluting? 6

Let’s take a ride through the wastewater system 6– The ins and outs of waste water 7

What do we know about agricultural pesticides and where they go? 8

THE USUAL SUSPECTS

What can we really say about the effects that all the chemicalswe use have on Australian Frogs? 9– Pesticides 9

Organochlorines 9Organophosphates 9Carbamates 9

– Herbicides and fungicides 9– Surfactants 10– Additives 10– Endocrine disrupting chemicals 10– Fertilisers 10– Combinations 10– Metabolites 11

TAKING ACTION

Where can I find out about these chemicals? 11

So what can you do? 12– What can you do with leftover hazardous household

products or pesticides? 13– Some alternative suggestions 13

The aim of this booklet is to help you understand:

What pollutants are

How frogs interact with their environment

Why water pollution affects frogs

Where pollutants come from and how they enter the environment

How you may be polluting water

Categories of pollutants (such as pesticides) and their effects on frogs

Where you can go for further information

What alternatives there are and what products you can substitute

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FROGS AS ENVIRONMENTAL BAROMETERS

What is a pollutant?Pollutants are potentially harmful, and sometimes lethal. It’s easy to think ofchemicals such as pesticides, detergents,industrial chemicals and so forth as pollutants. Less obvious examples might be extremely high nitrogen or phosphorus levels in water due to fertiliser runoff and sewerage discharges, or sediment from cleared lands. Salinity andlitter also cause pollution problems.

For the purposes of this booklet, our main emphasis is water-bornepollutants - those readily identifiableculprits such as pesticides,household detergents, assortedchemicals, and fertilisers.

Pesticides are substances (or mixtures ofsubstances) that are intended to prevent, kill, or repel a particular pest. ‘Pests’ are speciesthat we want to get rid of, for any number ofreasons. Pests can include insects, mice andother animals, unwanted plants (weeds), fungi,or microorganisms like bacteria and viruses.The term ‘pesticide’ therefore also includesherbicides and fungicides. Unfortunately, mostpesticides have some risk of harm to non-pestspecies precisely because they are designed to be harmful. Of course, many things can betoxic in high enough amounts, even caffeine andparsley, but such high amounts are very unlikelyto occur. Problems arise when the amounts weuse regularly are directly harmful, or accumulateto harmful concentrations in nature.

Australian frogsAustralia really is a lucky country – we havemore than 210 species of frogs! What is more,because Australia has been isolated from other land-masses for so long, our frog speciesare quite different from the species found in other countries. In Australia, we have three main native frog families. They are theMyobatrachidae (or ground frogs), the Hylidae(tree frogs), and the tropical Microhylidae.

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How do frogs interact withtheir environment?Life stagesFrogs generally start their life cycle as eggsencased in jelly capsules. Depending on thespecies, the eggs develop on land or in water. They gradually turn into tadpoles, hatch, andbecome free-swimming. Tadpoles breathe viagills, like fish. They continue to grow until theyreach a certain stage, when a complex hormonalprocess kicks in that changes them into frogs.This is called ‘metamorphosis’, and it is reallyquite remarkable. When they crawl out ontoland, the frogs are then mostly terrestrial andbreathe via their skin and the back of theirthroat. Frogs have an essentially "naked" egg (it doesn’t have a shell) and, along with otheramphibians such as salamanders and caecilians(neither of which are native to Australia), are theonly vertebrate group that has both an aquaticand terrestrial phase.

Habitat requirementsFrogs need an environment that is moist,because they ‘drink’ and breathe through their skin. Most species lay their eggs in water,so the availability of water is essential. Somefrogs have evolved to take advantage oftemporary pools of water that are created by heavy rain. Others lay their eggs in rivers,and yet others congregate around permanentponds and streams.

Ecological positionFrogs are important components of manyecological communities, consuming vastamounts of invertebrates and, in turn, providingan abundant food source for many otherpredators, such as birds and snakes.

Frogs and pollutants in the food chainIf pollutants affect frogs, this can then havecarry-on effects on the ecological community.Pollutants that may not be easily excreted or broken down by the body, can accumulate inbody tissues. This is known as ‘bioaccumulation’.When these animals or insects are thenconsumed by another animal, the toxins in theprey can then accumulate in the predator’sbody. This process is called ‘biomagnification’. After eating a few contaminated prey items, the concentrations of toxins in the body of top predators can become extremely high. Frogs can bioaccumulate toxins by ingestingcontaminated insects and also through directexposure to pollutants, particularly in the water.When frogs are killed by these pollutants, eitherdirectly, or because the pollutants make themvery sick and unable to escape a predator, thenthis causes problems all the way up the foodchain. Frogs, with their toxic payload, may makethe animals that eat them very sick. With fewerfrogs to eat insects, there are ecologicalproblems down the food chain as well.

Why is environmentalpollution a frog issue?The skin of a frog is very permeable. Thetadpole stage also relies on gills for breathing.Both of these physiological characteristics makefrogs and tadpoles very susceptible to a numberof contaminants, which often easily penetrateexposed surfaces such as gills and skin.

Consequently, because frogs inhabit water andland, they may have more opportunities to beexposed to environmental contaminants thanmany other animals. Frogs also have more waysof being exposed than other animals, becausethey have gills as tadpoles and a very permeableskin as an adult.

Frog limb abnormalities have been proposed as a possible indicator of environmentalabnormalities, particularly in agricultural areas.However, deformed frogs are rare in Australia.

Are frogs more sensitive to environmentalpollutants than other species?Yes and no. In some situations, and for sometoxins, frogs may be particularly susceptible to contamination. For example, the insecticideendosulfan is ten times more toxic to Ranatadpoles than to catfish or damselfly nymphs.We rarely test the effects various contaminantshave on adult frogs so in many cases, wesimply don’t know how sensitive they are.Unfortunately, there is not enough research toprovide a definitive answer to this question formost frog species.

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Why don’t we have all the answers?We are blessed with lots of frog species, but environmental toxicology is a relatively newfield here in Australia. The majority of aquatictoxicological testing usually focuses on speciessuch as fish, shrimp, and invertebrates.

How applicable are studies on fish andinvertebrates to frogs? Good question!!Generalisations are hard to make because afrog’s sensitivity also varies according to thespecific toxin tested. For example, we know thatfrogs do not react to mercury the same way fishdo. Consequently, we cannot assume that frogswill react the same way as other animals – oreven that all species of frogs will react thesame. However, frogs are more similar to fish in many ways than they are to birds and mammals.

At least 80% of the available researchon environmental contaminants andfrogs uses American and Europeanspecies. Unfortunately, these studiesmay have little direct relevance to the unique frog species andenvironmental conditions in Australia.

In many cases, we don’t know what chemicalsare, or might be, in our waterways. We alsodon’t know if or how they may combine to form new toxins. Nor do we know what they maybreak down into.

How relevant are these toxicity tests toreal world situations anyway?One of the most widespread protocols forassessing the toxicity of a chemical to anaquatic species is the acute toxicity test, which provides information about what sort ofconcentrations are overtly harmful to the testanimals. However, even though animals may notdie, they may get sick, or their growth may bestunted. Such chronic effects appear only afterweeks, months or years, and are much moredifficult, and costly, to assess. Bacteria and lightcan break down some chemicals into othersubstances and these may be more or lessharmful than the original compound.

Where do pollutants come from?Outside of natural disasters, almost allpollutants are the result of human activities,whether created directly, or as by-products of production processes.

How many chemicals do we use here in Australia?For a start, there are over 40,000 industrialchemicals listed by regulatory authorities, andover 4,500 agricultural and 3,000 veterinaryproducts registered for use in Australia. Do weknow the effects that each of these chemicalshave? Frogs are not a standard test species, soin most cases we don't know what they do tofrogs. In addition, many chemical formulationsare based on other, older formulations. Theseformulations have generally been originallytested a long time ago and so may not meetcontemporary standards. The AustralianPesticides & Veterinary Medicines Authority(APVMA) assesses existing chemicals inresponse to concerns about their health, trade or environmental effects.

Due to the huge number of chemicals in use,only a small proportion have been assessed and so we often don't know the effects that allthese chemicals have on frogs.

Unfortunately, information on agricultural and veterinary chemical usage is not formallycollected across Australia. We do know thatherbicides, insecticides and fungicides havebeen regularly used in Australian farming for at least 40 years. We also know that all forms of pesticide use have increased over the pasttwo decades and that we spend around a billiondollars on them annually.

Who produces pollutants?The list of who produces pollutants is enormous because many things that we use inday to day life either cause pollution while beingmanufactured, or become a pollutant when we finish with them.

Take, for example, most peoples’ morning routine.

You get out of bed. If it’s a wooden bed, the wood has usually been treated withpreservatives and anti-fungal agents, perhapssealed with a varnish. Many of these treatmentprocesses discharge waste water, not tomention the initial process to produce thepreservatives and varnishes, all of which arelikely to be toxic to frogs in variable amounts.Chlorinated phenols are used as woodpreservatives and pesticides, and are often the by-products of paper pulp milling. All thesechemicals are toxic in high doses.

If the sheets on the bed are cotton, they have usually undergone a bleaching and dyingprocess. Chlorine based bleaches can bedangerous to frogs. The cotton industry usesthousands of tonnes of insecticides every yearto control pests. Pesticides, and their effects on frogs, are discussed in much greater detail later on in this booklet. Your sheets arepartially polyester? Many plastics industries are again highly polluting. Bisphenol A, a high-volume chemical used to make polycarbonateplastic, epoxy resins, and other chemicals, hasbeen shown to be weakly estrogenic to fish. Estrogen is an important hormone that regulatesmany bodily functions in many animals,including frogs.

Polychlorinated biphenyls (PCBs), which arewidespread contaminants in industrializednations, were used to manufacture paints,plastics, adhesives and electrical goods (suchas transformers and capacitors), non-carboncopying paper and are used as hydraulic andcooling fluids. PCBs have been shown to cause reproductive failure in birds, cause liver,stomach and thyroid gland injuries and affectthe immune system in other animals. PCBs areso persistent and mobile in the environment thatalmost everyone has been exposed to them.

WHAT WE DO AND DON’T KNOW

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You grab your towel (again it is likely to becotton) and walk across to the bathroom. Think about the preserved and sealed wood of the floor, and how logging industries can also cause problems with erosion and sedimentinto rivers. The rug on the floor and the paint on the wall may be a source of acrylic acid. This acid is used to produce acrylic esters and resins, and used in detergent intermediatesand oil treatment chemicals. It is also emitted in the production of acrylate, and from polishes,paints, coatings, rug backings, adhesives,plastics, textiles and paper finishes. Accordingto the National Pollutant Inventory database(collated by the Department of Environment and Heritage DEH), about 90% of acrylic acid inthe environment is expected to end up in water.It has slight toxicity to aquatic organisms suchas fish and has high toxicity to birds.

In the bathroom, you step into the shower. Your shampoo bottle is usually made fromplastic. Its label is usually bleached paper (as is most toilet paper). Pulp and paper millsdischarge dioxins to air and billions of liters of liquid effluent each year. In fish, this effluentcan cause delays in sexual maturity and reducedegg production, depress sex steroids, causemasculinisation of female fish, and suppressimmune functions.

Your shampoo may contain up to 50ingredients. A number of them are foamingagents, or ‘surfactants’. Surfactants have beenshown to be harmful to frogs and are discussedmore extensively later on in this booklet, onpage 10. Some anti-dandruff shampoos containselenium. Excess selenium is associated withreproductive effects and mortality in wild birds,although we don’t have a good understanding of what it does to frogs. However, sodiumselenite has been shown to cause severedevelopmental abnormalities in the Africanclawed frog (Xenopus laevis) at concentrationsof 2 mg/L. One teaspoon of salt is 5,000 mg, so 2mg is a very tiny amount.

Your shaving cream may contain octylphenol, which is also a breakdown product of a chemical widely used in the pulp andpaper industry and is found in many commonhousehold cleaners. Octylphenol adverselyaffects both the growth of snapping turtle

hatchlings, and development in tadpoles. Your antiperspirant contains aluminium, whichmay have effects on the nervous system, and istoxic to frogs at concentrations of 0.86 - 1.6 mg/L.

Your toothpaste can contain carrageenen as athickener, triclosan as an antibacterial, andfluoride. The first can cause intestinal ulcerations,the second has been shown to accumulate in wildfish, and there is some evidence that fluoride-contaminated water can cause frog eggs to hatchprematurely. We don’t know what effects thesethings have on Australian frogs.

All of these products are washed down thedrain. Many trillions of litres of contaminatedwater flows through sewerage systems inAustralia every day. Although sewerage ispartially treated, treatment plants often do notcapture all the solids we rountinely flush downtoilets, such as wrappers, cigarette butts, dentalfloss, nappies, and toilet paper, let alone treatthings like chemicals, cleaning products and detergents.

At least 80% of water samples taken from riversand catchments in the USA in 1999 and 2000contained chemicals such as disinfectants,antibiotics, antioxidants, caffeine, fire-retardants, and fragrances. Surfactants and platicizers (such as 4-nonylphenol andbisphenol-A) were also found in over 50% of samples. The potential toxicological effects of most of these compounds are relativelyunknown. This means that many possiblecontaminants are entering our waterways, andwe simply do not know what effects they mayhave on our frogs. Research has shown thatcaffeine is teratogenic (i.e. causes birth defects)to the African clawed frog (Xenopus laevis)and causes malformations of embryos atconcentrations of 0.12 mg/L. One cup of coffeecontains 100mg caffeine. Interestingly, caffeinespray is now being used as a slug and snailkiller; and may also be used to control pestfrogs in Hawaii, by causing then to go intocardiac failure.

We haven’t even gotten to electricity, or yourmorning coffee, or breakfast, or cars, or roadsyet! This is meant to illustrate how things thatare either directly polluting, or are the result of an industry that pollutes, permeate our daily lives.

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WHAT’S HAPPENING?

So how am I polluting?Potential sources of pollution in a city or town include:

i. domestic pesticide useii. domestic fertiliser useiii. discharge from sewerage treatment

plants (both domestic and industrial sources)

iv. transport of pollutants and sediments via stormwater

v. irrigation drainage and runoff from roads

vi. groundwater contamination from land fills.

i.& ii. Domestic pesticide and fertiliser use:Many household products are classified aspesticides. Did you know that insect repellents;flea and tick sprays, powders, and pet collars;cockroach sprays and baits; rat and micepoisons; some kitchen, laundry and bathdisinfectants and sanitizers; mold and mildewkillers; some lawn and garden products (suchas weed killers); and some swimming poolchemicals are classified as pesticides?

Did you know that some flea powders, collars, and sprays may include carbamates,pyrethrins, chlorpyrifos, and organophosphates?If you have never heard of these chemicals, then perhaps now is a great chance to startlearning about them. I will define pesticides and their effects further on. Fertilisers cancontain heavy metals or change soil pH, or cause excess nutrients in waterways thatmay lead to algal blooms.

iii. Discharge from sewerage treatment plants:Many people flush things down the drainbecause its an easy way to get rid of them. In 2000-2001 Sydney Water collected 1,348cubic metres of litter from the litter booms,trash racks and gross pollutant traps. Sediment capture was almost 40,000 tonnes.This, however, is less than 70% of the solidsthat flow through the system.

A Sydney Water media release titled "HouseholdSinks Put Environment at Risk" on 02 May 2002cautioned that increasing amounts of paints,solvents, paint strippers, fuel, oil, food scraps,milk, cooking oil, small rubbish items such

as cigarette butts, bandage wrappers and cottontips (which slip through traps and filters),pesticides, and poisons are being tipped down the drain. When compared to 1994, an additional 2,174 tonnes of grease and oilentered the system in 2001. The Ministerresponsible for Sydney Water cautioned thatmany of these items may cause blockages inpipes, causing them to overflow, and smalleritems slip through screens and can end updirectly in waterways. Chemicals and poisonscan’t be screened and are difficult to treat, they too can end up in our waterways.

The responsibility lies with all of us. We cannot rely on the sewerage system to takecare of the household items we put down thedrain. Everything we do may directly affect ourwaterways and the frogs that live in them.We need to be mindful of what we do –in some cases it may be easy to changea behaviour. For example, one could pour oldmilk onto a garden bed, not down the drain(milk can clog up the treatment system). Andold paints and garden sprays can be taken tochemical disposals. There are suggestions anddetails on where one can safely dispose of old chemicals at the end of this booklet.

Let’s take a ride through thewastewater system…Sewerage:Sydney Water provides sewerage services to collect, transport and treat wastewater fromhouseholds and industry, for more than 3.9 million people. This equates to around 1,300 megalitres (a megalitre is one millionlitres) of wastewater every day! I mentionSydney Water only in order to illustrate howsewerage systems operate in Australia, andbecause so many Australians live in Sydney.Sydney Water also provides good informationservices, so we can get a better picture of what happens.

We already know that sewerage treatment plants do not eliminate all harmful contaminantsflowing through the system. For example, manyplants exhibit leaf damage when irrigated with'reuse' water, which is sewerage water that hashad partial treatment but is not yet drinkable.What we don’t know is exactly what things are

passing through, nor what effects they mighthave. The presence of many potentialcontaminants are not routinely monitored. Forexample, domestic inputs to sewerage workscontain natural and synthetic estrogens fromhuman excretion, such as estradiol. Very smallconcentrations of estradiol have been shown to cause many developing African clawed frog(Xenopus laevis) embryos to become female.Estrogens in the environment, or chemicals thatmimic oestrogens, are thought to disrupt manyhormonal processes in aquatic animals.Chemicals that do this are known as ‘EndocrineDisrupting Chemicals’ (EDCs), and arediscussed more comprehensively later on.

Effluent and receiving waters around Sydneysewerage treatment plants (STPs) have beenfound to contain significant amounts of metalssuch as boron, cadmium, cobalt, copper (which causes gastrointestinal, liver and kidneyproblems in humans, and disrupts gill function in fish), silver, iron, lead (which can delay mentaldevelopment in humans and cause kidneyproblems), mercury, manganese and nickel.Many heavy metals are acutely toxic to fish andfrogs. For example, cadmium causes mortality in a salamander, Ambystoma opacum, at concentrations above 10.2 µg/L. A teaspoon of salt is about 5 million µg (not including thespoon, of course!), so 10 µg (called"micrograms"),is about as much as a single grain of salt in alitre of water. Metals are heavier than salt, so theamount we are talking about here is very, very,very tiny.

The maximum concentrations of aluminium in effluent and receiving waters at Blackheath,NSW over the past six years ranged between110 µg/L and 1,420 µg/L. These are 2 to 25times the trigger value of the Australian andNew Zealand Water Quality Guidelines, andtherefore likely to be harmful to organisms such as tadpoles that inhabit these waters.Aluminium is toxic to the American toad (Bufo americanus) at concentrations between860-1,660 µg/L. Remember that a teaspoon of salt is about 5 million µg, so this is less than 1/3,000 of a teaspoon!

STP discharges have also been found to containcyanide (which disrupts respiratory functions in animals), chlorpyrifos (an organophosphateinsecticide), dieldrin (an organochlorine

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High Volumes (eg. 1,300,000,000 L per day in Sydney)

No tests for some contaminants

solidsmilk detergentspaintcleaning productspesticidesetc.

road debrisoildetergentsweedkillerspetroletc.

irrigation

incinerators - dioxins

changes in vegetation

ash & soil conditioners - heavy metals - pH

to streams etc.

ground water

ground water

SewerageTreatment

Plants

Solid Output

Liquid Output

heavy metals - aluminium - chromium - boron - mercury - lead

pesticides

caffeine

painkillers

benzene

surfactants

urea

hormones

chlorine

nitrate

input to drains, toilets etc.

storm water

by-pass

The in’s and out’s of waste water

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insecticide), chloramines, and nonyl phenolethoxylates (surfactants).

Residual chlorine (used to disinfect drinkingwater and sewerage, also contained in manyhome disinfectants) has been detected in theeffluent and receiving waters of Sydney STPsfor several years. The observed maximumconcentration in the effluent and receivingwaters at Castle Hill, NSW during 1999/2000was 2,230 mg/L – a total load of 1,829.28 kg in one year. This value is double or triple theconcentration that kills fish, because chlorine istoxic to freshwater fish at concentrations of 70-840 µg/L. Many sewerage treatment places suchas Sydney water are committed to improvingwater quality around discharge sites. But it is a big and expensive job.

It is highly unlikely that discharges will ever beharmless. Therefore, it is up to all of us to bemindful of what we add to this toxic burden onour waterways. We can all help frogs by notputting harmful things down the drain.

iv. Transport of pollutants and sedimentsvia stormwater The litter you throw in the streets, the oil yourcar drips onto the road, and the soap suds youwash off your car can all make it through thestormwater drains and into your local river.

A secondary consequence of stormwater is thatat times of higher flows (such as during intenserainfall) the capacity of STPs to treat andmanage wastewater becomes weakened, andthus flows bypass some treatment processes.Consequently, partially treated sewerage can bedischarged directly into rivers. Such dischargescan generate an acute pollution episode. An example of this is the 300 tonnes of deadfish removed from a river in France after astorm event in 1992.

v. Irrigation drainage‘Spray-drift’ and ‘run-off’ are terms thatdescribe when contaminants move away fromthe place where they were intended. Chemicalsprays, particularly fine ones, can be blown a long distance by the wind. This can causeserious problems in agricultural operationswhere spray is released from aeroplanes or bigmachinery, but it can also be a problem in yourown backyard if you spray on a windy day.

Run-off occurs when chemicals have beenapplied to plants and then water (either rain or irrigation) washes these chemicals off theplants, and either into the soil or off into dams,creeks and rivers.

vi. Groundwater contamination fromlandfills and industrial activities: ‘Groundwater’ is the underground reservoir that supplies wells, springs, and creeks. It provides around 20% of Australia’s total water requirements; this figure increases to 100% in some remote mining settlements.

Deep below ground, it may still becomecontaminated by agricultural and industrialactivities. Even your own backyard has thepotential to affect groundwater in surroundingareas. Agricultural dip-sites (especially wherearsenic and organochlorine products wereused), old metal smelting sites (such as copperand lead), closed tips, gas plants and works,garages, power stations (where buriedhydrocarbons and heavy metals occur),manufacturing spills, broken pipelines, andmining-related activities and bores are all siteswhere contaminants can leach through the soilto groundwater unless responsibly managed.

What do we know aboutagricultural pesticides andwhere they go? Although agriculture is the largest user ofpesticides, significant quantities of herbicidesare also used by local councils and road and railauthorities for weed control.

We do not know the total contaminant load in Australia - how much is used and where it is used -we can only make estimates based on the amount of money spent per year.The problem with estimates is their uncertainty.Chemicals may break down or degrade, andthese degradation products may act in manydifferent and unpredictable ways. Chemicals can also move off-target. Refer to diagrambelow. For example, 1) those which are sprayedcan move through the air, 2) those applieddirectly to the soil may be washed off intonearby surface water, or 3) they may percolatethrough the soil to groundwater, 4) groundwatercan also transport chemicals into surface waterbodies or irrigation water sources elsewhere,and 5) sediment can be an additional potentialsource of exposure. Lastly, the potential effectsof exposure to multiple pesticides applied in agiven area cannot be assessed.

So now that I have talked about the numbersand volumes of chemicals we use ourselves,how can we tell what effects these may have on frogs?

wind volatilization

photodegradation

runoff

Sorption tosoil particles

Leach to groundwater microbial orchemical degradation

plant uptake

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What can we really say about the effects that all thechemicals we use have onAustralian frogs?Unfortunately, the answer is: we can say verylittle. Existing research suggests that manyproducts have the potential to be harmful, but inmost cases we simply don’t know. We areforced to make educated guesses.

I have listed three main categories ofcontaminants:

Pesticides, Surfactants (detergents, soaps, wetting agents, and their metabolites) and adhesivesFertilisers and heavy metals.

This list is by no means comprehensive, andmany compounds and their effects simplycannot be included here (unless you really wantto read a tome the size of the Sydney telephonedirectory!). The idea here is to introduce you tothe sorts of things that are commonly used andsome of the possible effects they can have.

Pesticides:There are currently over 4,500 agriculturalpesticide products registered for use inAustralia. These products are used extensivelyin both urban and rural environments. Any givenactive ingredient can be used in many differentbrands and formulations. For example, theherbicide 2,4-D has over 100 trade names and formulations.

When used according to label directions, manypesticides should be relatively safe for humans,However, again, we are generally unsure whateffects they have on frogs. Moreover, when they move off target, breakdown or accumulatein water bodies, then their effects may be much worse.

Since the term ‘pesticide’ incorporates manyproducts such as insecticides and herbicides, Ihave split the topic into six sub-sections whichcan be read in any order. Three subsectionsdiscuss some of the major types of insecticides:the organochlorines; the organophosphates; andthe carbamates. The next three subsections willbriefly outline herbicides, then additives, and the

final section is a special case of compounds thathave particular action. These are the endocrinedisrupting chemicals.

OrganochlorinesOrganochlorines were the first syntheticchemical pest control agents, and include DDT,chlordane, lindane, endosulfan, metolachlor,pronamide and heptachlor. DDT was usedextensively in developed nations until it wasbanned from use in the USA in 1972 andAustralia in the mid 1980's, although it is stillwidely used in much of the rest of the world.

DDT, and most other organochlorines, have veryhigh environmental persistence. For example, arecent study found that the average residuelevels of DDT in the stomach contents of birdsin Australia in 1990 were 179.21 µg/L (a µg isone millionth of a gram) despite not being usedfor 20 years. Harmful effects have been reportedin one frog species at concentrations as low as2 µg/L DDT. This amount is equivalent to twopinches of salt in ten tons of potato chips.

Organochlorine residues continue to be detectedin fish from the Mississippi River Basin.

Organochlorine pesticides such as endosulfanare still being used in Australia. Endosulfanattacks the central nervous system in mammals,but we don’t know what it does to frogs.

Organochlorines such as dieldrin, endosulfan,toxaphene, and chlordane are also weaklyestrogenic (they act as hormone mimics).Endocrine disrupting chemicals have beenshown to cause extensive limb malformations inthe frogs Rana clamitans and Rana catesbeiana.Despite widespread contamination, very fewstudies have measured organochlorine residuesin native Australian frogs.

OrganophosphatesToday, organophosphates have partially replaced organochlorines because of their lowerenvironmental persistence. Organophosphatestend to inhibit cholinesterase, disrupt enzymeprocesses and nerve impulses, or denatureproteins. In Australia, we use them extensivelyin agriculture and within urban areas.

The organophosphate pesticides diazinon andchlorpyrifos are active ingredients in a numberof domestic garden pesticides and both havebeen detected in effluent and receiving waters in

most Sydney STPs. The observed maximumconcentration of diazinon was 1.71 µg/L. Littleinformation is available on the effects ofdiazinon on frogs. As an illustration, a search of a scientific journal database produced 1,553papers that mentioned diazinon. Only one of these was on frogs. This paper, a Canadianstudy, found that the lethal concentration of diazinon to green frogs (Rana clamitans)was 2.8 to 5 µg/L.

Therefore, we don’t know their potential risksto Australian frogs.

CarbamatesLike organophosphates, the low persistence of carbamate insecticides has led to theirwidespread acceptance. Carbamates oftendisrupt the movement of nerve impulses.Despite their acceptance, carbamate basedinsecticides have been found to producedevelopmental malformations in skeletal tissue and musculature of Rana species.Exposure of Xenopus laevis and Hyla tadpolesto carbaryl caused mortality at someconcentrations and changed swimmingbehaviour at others. In addition, its toxicityincreased tenfold in the presence of ultraviolet-B radiation.

We can assume the effects on Australianspecies are likely to be similar, but until formalstudies are conducted, the real dangers remainvirtually unknown.

Herbicides and fungicides:Atrazine is the most commonly used herbicidein the U.S. In Australia, atrazine has been foundto contaminate as much as 50% of groundwatersamples in some areas, although the extent ofgroundwater testing is extremely limited.

Recent research has found that male Africanclawed frogs (Xenopus laevis) suffered a tenfolddecrease in testosterone levels when exposed to25 ppb (parts per billion) atrazine. One part perbillion is the equivalent of one drop of impurityin 500 barrels of water. Paraquat has beenfound to cause malformations to Xenopus laevisembryos at concentrations of 0.2 mg/L. Thefungicide Vinclozolin alters sex differentiation of male rats. Again, we do not know the effectsof atrazine, or many other herbicides, on Australia frogs.

THE USUAL SUSPECTS

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Surfactants:Synthetic surfactants can also contribute towater pollution, as around 7 million tons areproduced worldwide every year. Surfactants are used in many compounds to break down the surface tension in water, and help themdisperse. Alkylphenols and alkylphenolethoxylates (APEs) are commonly used in many industrial, agricultural and domesticapplications. Both of the surfactants alcoholethoxylate and alcohol ethoxy sulfate werefound to have toxic effects on Xenopus laevisembryos and tadpoles. In particular, embryoshad malformed gills. These two surfactants areused extensively in consumer products.

It appears that alkylphenols were not tested forin effluent of STPs here in Australia until lastyear. Nevertheless, nonyl phenol ethoxylateswere detected in effluent and receiving waters at Blackheath in 2000/2001. Although sewerageworks treat effluent, they are not yet effective at removing many contaminants.

Additives:We tend to know formulations only by theiractive ingredient, with little regard to the manyother additives that are not listed on the label.

Here in Australia, Dr. Reinier Mann undertookresearch on glyphosate. Glyphosate is supposedto be one of the most non-toxic herbicidesavailable. Dr. Mann found that the surfactant,not the active ingredient, had serious impactson frogs and tadpoles; therefore, compoundsconsidered safe may not be safe at all. These sorts of findings can lead to companieschanging the formulations of their products,however, such harmful effects are simplyunknown until someone does research on it. Unfortunately, the amount of money spent on such research is vanishingly small.

Endocrine disrupting chemicals:Many environmental contaminants, such as

plasticizers and pharmaceuticals, are known to have estrogenic effects, or behave ashormone mimics or disruptors. These ultimately affect basic life functions such asgrowth, reproduction and development, andmaintenance of the body. Without killingindividuals, they can seriously jeopardise whole populations.

While DDT is one such compound, thealkylphenolic surfactants used in items such as detergents, paints and pesticides may be ofgreater concern. These chemicals are also usedin industries including pulp and paper, textiles,pesticides, metals and plastics, and institutionaland household cleansers. For example, aconcentration of 16 µg/L Bisphenol A (a high-volume chemical used to makepolycarbonate plastic, epoxy resins, and otherchemicals), altered the proportion of sex celltypes in the testis of male fish, while higherconcentrations inhibited gonadal growth in bothsexes of fish. Remember than a microgram is one millionth of a gram. Bisphenol A alsobioconcentrates in freshwater clams and lower water temperatures causes it to persist evenlonger in tissues.

A high incidence of intersexuality has beenobserved in wild populations of riverine fish inmany parts of the United Kingdom – this sexualdisruption is associated with exposure toeffluents from sewerage treatment works.

Again, the effect of endocrine disruptingchemicals has not yet been studied in Australian frogs.

Fertilisers:Fertilisers have only recently been proposed as a potential threat to frogs, but it is one of the most serious problems at a local level.Researchers in the northern hemisphere noted a correlation between amphibian declines and environmental increases in nitrates and ammonia.

Sublethal concentrations of nitrite in watercaused both physical and behavioural changes in the Cascades frog in the USA. Urea fertiliser decreased survival in twoAmerican amphibian species.

Australian frogs have evolved in an environmentthat is comparatively low in nitrate andphosphate, so it is possible that Australian frogs may have a greater sensitivity to thesechemicals. Nitrates are becoming a largerconcern among environmental monitoringagencies in Australia because nitratecontamination is considered the most significantand widespread contaminant of groundwater.The main problem with increased nitrateconcentrations is the potential to stimulate algal growth and blooms. At high enoughconcentrations, nitrate is toxic to aquatic life.

In temperate areas in south eastern SouthAustralia, dairies, piggery feedlots, cheesefactories, abattoirs, and spreading of wastes,nitrogenous fertilisers and natural leaching of leguminous fertilisers can greatly increaseconcentrations of nitrate in groundwater.Sugarcane growing is a major source of nitratecontamination in groundwater in coastalQueensland. Indeed, increased nutrient load is already affecting the Great Barrier Reef.

Fertilisers can also dramatically change soilchemistry, such as pH, and heavy metal content.Acidity can also lead to mobilisation of metalssuch as aluminium & iron and can increasechemical demand for dissolved oxygen inwaterways, leading to lower oxygen availabilityfor fish and tadpoles. pH also alters howtadpoles react to fungal attack, bacterialinfection, or how they are affected by heavymetals or UV-B radiation, and so on.

Many fertilisers contain impurities such ascadmium, lead and mercury. Most heavy metalssuch as mercury, boron, cadmium and coboltare harmful to frogs. Mercury, for example, isone of the most toxic compounds to frogs yetfound. This means that fertilisers may haveconsiderable long-term impacts on our frogspecies; either directly, or through modifyingother variables such as pH and metal impurities.

Combinations:Commercial preparations are often acombination of two or more pesticides or they incorporate various solvents, carriers or surfactants. Biological testing is generallyonly done on the active ingredients.

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TAKING ACTION

Some chemical combinations may have additiveor synergistic effects, that is, the combinedeffect is much greater than just the sum of the effects that each compound has by itself. They may also combine with otherenvironmental parameters such as pH.

Although little is known about interactiveeffects, the potential implications ofcontaminant mixtures are serious.

Metabolites:We also need to consider that chemicals breakdown in the natural environment. Methoprene,used for controlling mosquitoes and fire ants, is considered comparatively safe and inert. Itsan insect growth regulator that interferes withinsect development. Such biologically-basedpesticides, or others that utilise pheromonesand microorganisms, are becoming increasinglypopular because they are often considered saferthan traditional chemical pesticides.

However, the photoproducts and metabolites of methoprene, which form as it breaks down in sunlight, have been found to causedevelopmental deformities in the African frogXenopus laevis. Although the concentrationsused were much higher than would be expectedif the product was used according to directions,they still indicate cause for concern, especiallyin cases where the amounts used do not complywith the label directions.

So, products previously considered safe forfrogs may not be so safe after all. Here aresome other questions for you. What do wereally know about the products used in thehome and garden? Many chemicals are labelledas “Readily Biodegradable”, but what do theydegrade to? Its not specified on the label. Infact, many ingredients are not listed on the labelat all, or simply generalised to: “sudsing agent”,“thickener”, “cleaning agent” and the like. Ofcourse, many products really are safe to use -but which ones? for how long? and safe forwhat animals? I mention all this in order to raisequestions in your mind about the products weuse everyday.

Where can I find out aboutthese chemicals?There are a number of handbooks available,such as “The Pesticide Manual”, edited by CDS Tomlin and published by the British Crop Protection Council (2000), and “TheAgrochemicals Handbook”, edited by Kidd &James (1991), and published by The RoyalSociety of Chemistry, Information Services,Cambridge, England. It lists many pesticides,their chemical composition, and toxicology data on various test species, but such technical handbooks are big and heavy and sometimes expensive.

Or you can contact agencies such as theEnvironmental Protection Agency and the APVMA.

Probably your best bet is the world-wide-web.Quite a lot of information is readily accessibleon various toxicology websites. However, bewarned that not all of the information on the web is scientifically based and can makeunsubstantiated claims.

In Australia:

Regulatory and governmental sites:

National Industrial Chemicals Notification andAssessment Scheme (NICNAS):www.nicnas.gov.au/australia/NRA.html

The National River Contaminants Program: www.rivers.gov.au

The Environmental Protection Agency:

- NSW: www.epa.nsw.gov.au

- NSW EPA | What are pesticides? www.epa.nsw.gov.au/envirom/pestwhtr.htm

- SA: www.environment.sa.gov.au/epa/epa/

Australian Pesticides & Veterinary Medicines Authority: www.apvma.gov.au

Department of Environment & Heritage:

Department of Environment and Heritage:www.deh.gov.au

Inland Waters: www.deh.gov.au/water/

National Pollutant Inventory: www.npi.gov.au (this site has thorough reviews,but only includes a limited number of pollutants)

Australian Water Resources Assessment 2000:audit.deh.gov.au/ANRA/water/docs/national/Water_Contents.html

Waterwatch : www.waterwatch.org.au/

- ACT: www.act.waterwatch.org.au/

- Vic: www.vic.waterwatch.org.au/

- QLD: www.qld.waterwatch.org.au/

- Tas: www.tased.edu.au/tasonline/dorsetww/

- NT: www.lpe.nt.gov.au/waterwatch/

- WA: www.wrc.wa.gov.au/ribbons/index.html

Sydney Water: www.sydneywater.com.au

Land & Water Australia: www.lwa.gov.au

Australasian Society for Ecotoxicology:www.ecotox.org.au

Food Standards Australia New Zealand:www.foodstandards.gov.au/aboutus/

Other:

Streamwatch: www.streamwatch.org.au/main.jsp

Cooperative Research Centre for Water Qualityand Treatment: www.waterquality.crc.org.au/

International sites:

Swedish EPA:www.internat.naturvardsverket.se/index.php3

WWF Canada. Reducing your risk to pesticides:www.wwf.ca/satellite/reduce-risk/index.html

Agency for Toxic Substances and Disease Registry:www.atsdr.cdc.gov/atsdrhome.html(Agency of the U.S. Department of Health and Human Services - it provides information on substances and priority lists of the mosthazardous ones and includes some verythorough reviews)

US EPA: www.epa.gov

US EPA Office of Pesticide Programs:www.epa.gov/pesticides/ (Highly recommended site).

US EPA Office of Pollution Prevention & Toxics:www.epa.gov/opptintr/index.html

California Department of Pesticide Regulation:www.cdpr.ca.gov

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United States Department of Agriculture:www.usda.gov/

Pesticide databases:www.cipm.ncsu.edu/index.html

The EXtension TOXicology NETwork EXTOXNET:ace.orst.edu/info/extoxnet/ (Highly recommended site for specific pesticideinformation - easy to use)

Environmental, lifestyle and personal sites:

Burke’s Backyard, chemical disposal:www.burkesbackyard.com.au/2002/archives/2002/conservation_&_the_environment/chemical_disposal

www.rfu.org/AboutPulp.htm (about the pulp and paper industry)

Environmental Media Services:www.ems.org/household_cleaners/information.html(some great info on alternative cleaners and linksto other sites)

Reach For Unbleached! - Consumer educationabout paper and pulp mill monitoringwww.rfu.org/index.htm

WWF: www.wwf.org.au

So what can you do?Since easy answers are not at our fingertips, we need to employ some basic common sense.Sometimes a non-chemical method of cleaningor pest control is as effective as a chemicalalternative. Sometimes we can minimize thechemicals we perhaps need to use, and anyreduction is a step in the right direction for our frogs.

My common-sense ideas would be these: � First, don’t use chemicals gratuitously.

Be reasonable. Ask yourself if your lawn has to be completely free of weeds, can you choose hardier plants, do you need tobleach the bathroom every week, and so on.If its not really necessary, then don’t use it.

� Use compost in preference to a commercialfertiliser. If you don’t want to compost, at least try more natural alternatives such as manure, seaweed, and fish emulsionfertilisers. The timing and placement offertilisers can minimise off-site lossesthrough runoff. Placement within the soil is preferable to surface application.

� Take advantage of web-based sites andmaterial to check the products you think you will be using often. You may have achoice between a few different products –these sites might help you decide whichwould be the least damaging.

� If you need it for a specific purpose or pest,try to use products with very narrow modesof action rather than broad spectrum onesthat have across-the-board effects. Forexample, a number of insecticides are insectgrowth regulators, and interfere with specificmoulting processes. One example is precor,a flea control liquid. These narrow modeproducts are less likely to have an impact on vertebrates.

� Consider where you are using the product.When it rains will it just wash off into thenearest pond, catchment or drain? Whathappens then? Can you prevent this runoff?

� It’s often easier to exclude pests than to control them. You can often preventcockroaches and household insect pests by removing food scraps and storing food in sealed containers. Block off indoor pesthiding places. Use sticky traps. Removestanding water, such as under indoor plants,and fix leaky pipes, because even pests need water.

� Most importantly, always read the label anduse according to instructions. Its importantto not only read the label before buying the product, but also to read the label everytime you want to mix or use the product,and before storing or disposing of it. Many contamination events are becauseformulations have been used incorrectly:Sometimes people simply don’t read thelabel; or they have used the product foryears, without checking to see if the formulation has changed; or people use products just before it rains, so theproduct washes straight off into the nearestwaterway. Formulations for high volumerates might be used with low volumeequipment, concentrating it; or people may add just a little more to make sure. I’m sure we have all done this in cooking!When it comes to being frog-friendly,though, its not worth the risk.

� If the chemical treatment didn’t work, do not assume that using more pesticide thanthe label recommends will do a better job. It won’t. You will need to find an alternative.

TAKING ACTION

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What can you do with leftover hazardoushousehold products or pesticides?

DO:

� Try to use up all of the product.

� If you simply can’t use it anymore, then give useable, leftover products tofriends or neighbours.

� Take unwanted products and potentially dangerous waste to a household hazardouswaste disposal program (see below).

Sydney Water runs a tremendous household chemical collection program, where you candrop off most types of chemicals, paints and the like. Phone 1800 814 719.

- National Chemical Collection initiative within AustraliaPhone 1800 008 182www.chemclear.com.au

- EcoRecycle Victoria (03) 9639 3322 or Infoline: 1800 353233 (within Victoria).www.ecorecycle.vic.gov.au

- DrumMuster (national program for the collection and recycling of empty, cleaned, non-returnable farm chemical containers).Phone: (02) 62306712. www.drummuster.com.au

DON’T pour leftover products orpesticides:

� Down storm drains or into creeks, because storm drains often send waterdirectly to our creeks or the ocean withouttreatment. Toxins can poison fish, plants andtadpoles, and can even end up in drinkingwater supplies.

� Down your sink or toilet, because manychemicals may pass through the treatmentplant untreated, and poison waterways. They may even interfere with the operationof wastewater treatment systems.

� On the ground, because they may seep into groundwater or be washed down storm drains.

� Into your garbage bin, because they could seep into our groundwater from the landfill.However, water-based paints could be left todry out and then placed in the garbage bin.

� Lastly, don’t burn them, because they often also release toxic fumes when they burn.

Some alternative suggestions (however, I have not personally testedall of them):

� Degreasers: Use citrus-based or water-based detergents. Avoid products with methylene chloride.

� Detergents: Avoid products with phosphates. Try laundry soaps. AVOID chlorine bleaches.If you need bleach, use a hydrogen-peroxidebased one.

� Surface cleaners: Try lemon juice andvinegar to cut grease. Borax can be used to soften water in order to preventsoapy deposits. Try to use vegetable oil based soaps.

� Drain openers: Using a sink strainer eliminates most problems. Pour boilingwater down drains once a week to eliminategrease. If a drain is partially clogged, tryputting in some baking soda with 1/2 a cupof vinegar, and seal the drain. This producescarbon dioxide bubbles which may dislodgethe obstruction. Uncover and follow with boiling water.

� Oven cleaner: Try a baking soda, salt andwater paste.

� Mildew: Scrub with a mix of borax and water on a scouring sponge. Full strength vinegar is more powerful, but don’t forget to rinse. Again, avoidchlorine based mold killers.

� Toilet: Clean often with baking soda. Let a cup of borax stand in the bowlovernight for a more serious clean.

� Furniture polish: Use almond, walnut, olive,or linseed oil.

� Wash your car on the lawn if possible, so that the soap doesn’t run into the storm water drains.

� Fleas: Obviously the first step is to vacuum regularly and washing pet bedding often. Empty the vacuum cleaner bag every timeand seal in a bag in the garbage. Steamcleaning carpet may also kill adult andjuvenile fleas. Try using an insect growthregulator to prevent larvae from maturing.Pyrethrins are considered the least harmfulof the adult flea pesticides, but be carefulthat the pyrethrin isn’t mixed with othermore toxic ingredients. Wash pets with a citrus oil shampoo and use a flea comb.Sometimes herbal flea collars withingredients such as eucalyptus, citronellaand cedarwood can work well.

� Mosquitoes: Screens on windows and doors are the biggest help. Remove standingwater near the house. Frogs and spiders aregreat insect predators so encourage them to hang around! If you must use a repellent,try citronella ones. And avoid wearingstrong-smelling products (which seem to attract mosquitoes).

To be frog-friendly, we all need toconsider our choices and their potentialfor harm.