Paper of the Week: Beware the Lead

Staunch supporters of game will find little to be pleased with the research published by Deborah Pain (of Wildfowl and Wetlands Trust, Gloucestershire) and colleagues, on Potential Hazard to Human Health from Exposure to Fragments of Lead Bullets and Shot in the Tissues of Game Animals in PLoS. The findings would also shock those who happily dig into the cooked game, seldom pondering about how much lead is ingested in the process.

Lead ammunition (pellets/bullets) is often used to shoot down game. To solve their research question, Pain and her colleagues bought wild-shot game birds (grouse, mallard, partridge, pheasant, pigeon, and woodcock) from supermarkets, game dealers, shoots, and butchers. After X-raying these to determine the number of shot and shot fragments present, these were cooked using typical recipes (in wine or cider or pH-neutral cream sauce). Mimicking the traditional game eating behaviour, the visible lead fragments were manually removed.

The lead concentrations in the remaining flesh were analysed. The results demonstrated that the game tissue is littered with small pieces of shot- most likely due to the ammunition disintegrating into smaller particles upon impact (and, in some cases, these fragments embed into the tissues even though the shot exits the body). Consequently, a higher level of consumption of some species may result in exceeding the current FAO/WHO’s weekly tolerable intake of lead. For instance, weekly consumption of three meals of woodcock and/or ten meals of grouse / partridge / pheasant would certainly take a 70 kilogram person over this threshold.

So does the consumption of game birds (shot with lead) pose a threat to humans? – The answer is very much an ‘yes’ although this depends on the amount of game consumed. As in most studies, the vulnerable population stands a good risk. And one mustn’t overlook the impact on the food chains/webs- fauna which consume these shot game birds are inevitably affected as well.


Pain DJ, Cromie RL, Newth J, Brown MJ, Crutcher E, Hardman P, Hurst L, Mateo R, Meharg AA, Moran AC, Raab A, Taggart MA, & Green RE (2010). Potential hazard to human health from exposure to fragments of lead bullets and shot in the tissues of game animals. PloS one, 5 (4) PMID: 20436670

Restoration

As was pointed out graphically by Sarah in her blog Our Gossamer Planet the forests of the world are disappearing at an alarming rate. The highest proportional rate of forest loss is in the United States, with a huge 6% loss of their trees from 2000 to 2005. However, the greatest total loss was in Brazil, a massive 165,000 sq. km.

Many people around the world are interested in rehabilitation of tropical forest, but despite this there is no real agreement on the best way to go about it. To look at some of the nitty gritty involved here is one detailed study that illustrates the problems (Jose Camargo et al, 2002, Rehabilitation of Degraded Areas of Central Amazonia Using Direct Sowing of Forest Tree Seeds, Restoration Ecology, 10, 636-644).

How does one make a forest?

The usual method in forestry is to plant seedlings, and this has been tried in forest reclamation, but it is expensive and time consuming, and not practical for large areas. Cheaper and easier would be use to use seeds, and they are also less susceptible to injury during planting by unskilled hands, but would they germinate? Part of the problem is the poor quality of the soil, made worse by poor agriculture. Also, which species? If you just want something growing there, one of the most successful on abandoned ex-forest land is Eucalyptus, but it is hardly a native flora. Renovating a temperate oak forest is relatively simple, just plant lots of oak (well ok, it´s a bit more than that), but the Amazon forest is characterised by an extreme diversity of plants, all in intense competition for very limited resources. Which to use?

Camargo and his team chose 11 native species, ranging from pioneer species to those of more established forest. This in itself is a problem, as the very number of Amazon trees means that most are not characterised yet. Also, some are dormant until they receive the right stimulus such as hot water or perforation.

They then chose four sites, intact forest, with trees about 20-30m tall, secondary forest dominated by shrubs and saplings of pioneer trees, up to 5m tall, abandoned pasture consisting of grasses and herbs, and, most hostile of all, bare earth from a highway project, compacted and stripped of top soil.

So, what happened?

After one year only one, the Piquia (Caryocar villosum), survived on all sites. The problems of a seed begin as soon as it hits the ground. Seed predation was high and seedlings suffered from fungi, predation and low light in the shade (germination was much higher on bare earth). Of the pioneer species, not one seedling was alive at any site after one year.

Caryocar villosum is a very large tree, 40-50 m tall. One reason for the success of the Piquia was it´s hard spiny shell defeating predation, whilst others suffered heavily. It also grew spectacularly fast, reaching 100 cm after just a year in some conditions, allowing it to escape shade very quickly.

The 2nd success was Parkia multijuga. P. multijuga has the advantage that it is a member of the legume family like peas and beans, and so, in effect, makes it´s own fertiliser. It´s therefore much less reliant than other trees on finding symbiotic mycorrhizal fungi in the soil, and in fact it actually renovates poor soil, adding nitrogen.

One of the surprises of this study was the failure of the pioneer species. These are plants that rely on producing huge numbers of very small seeds that drift on the wind, which spreads them over a huge area. This means that when new habitats become available they will usually be there ready, a big advantage. It might be expected therefore that these are exactly the trees to chose when starting a new forest. In contrast, it was those trees that produce huge seeds that more or less drop straight down and rely on animals to move them a little way from the truck, that survived. Why? Well the main benefits of the small seed/pioneer strategy are increased dispersal range and access to new germination sites, both of which are negated by direct planting. But also, the sheer hostility of the environment was unexpected. Large seeds are not a guarantee of success, as other studies have shown, but they do give the potential to grow fast escaping the shade of your rivals, and also the spare capacity to produce toxins, important when there are so many herbivores about. In the Amazon, any sort of ground cover harbours massive numbers of insects that chop up seedlings, one reason why germination was more successful on the bare, safe, earth.

In the end, out of 11 species tested, the authors could only recommend Caryocar villosum and Parkia multijuga for rehabilitation work, both non-pioneers with very large seeds. This is a still a big step forward, and gives a place to start.

There will be, hopefully, a lot of reforestation in the future. What this paper, and others like it, show is that it has to be done only after careful study, or a lot of effort will be wasted. There is a price to pay for the convenience and saving from avoiding nurseries and planting direct, and that price is paid by the plants. Without the care and protection of a nursery, life is very risky for seedlings.

Lastly, the long term future of any "new" forest has to be considered. For example the timber of Piquia is know to be excellent, and is used for housing and boats in the Amazon region. A forest mainly consisting of Piquia would be very tempting to loggers in the future.

Camargo, J., Ferraz, I., & Imakawa, A. (2002). Rehabilitation of Degraded Areas of Central Amazonia Using Direct Sowing of Forest Tree Seeds Restoration Ecology, 10 (4), 636-644 DOI: 10.1046/j.1526-100X.2002.01044.x

Red, Blue, Yellow & Green

Today, the nation woke up to a shift from Red to Blue. However, with no clear majority, which party is going to form the new government is anyone’s guess. Media accounts suggest that the Blues might coalesce with the Yellows. But what does the election mean for green issues. ‘Hopeful’ is the best word to sum it. The green party now has representation in the parliament. The voters of Brighton made history by electing Caroline Lucas to represent them as the first Green party MP. But will her voice be solitary in the parliament floor? One hopes not, in fact Richmond Park elected the Conservative party candidate Zac Goldsmith who could also fly the flag for green issues. Zac has strong green testimonials as the founder of the Ecologist magazine, advisor for Tories on environmental issues and a supporter of many green issues including his opposition to the third runway in Heathrow. Things are indeed looking bright and green!

Nature and Nurture: For the Future

The least movement is of importance to all nature. The entire ocean is affected by a pebble. Blaise Pascal

My original question was: ‘How can parents mold the environmentally responsible citizens of tomorrow?’, which was succeeded by discussions on Pets and on Like a Garden.

Now, this was not just a random query, but one of importance. These future citizens of tomorrow are those who, with their choices and attitudes, sculpt the earth of tomorrow regardless of whether or not they occupy key role in political governance. Thus, parents have crucial role to play, given the great degree of responsibility lying in these hands.

It would be inane to doggedly insist that mankind has not contributed to environmental degradation. The question which faces us now is about what can be done to rectify this degradation which mostly happened as a result of the race towards development. Whilst it might be hard to attain the state of the environment (before it was sullied), we can still, with proactive participation by each individual, prevent further deterioration, and if possible, try to restore some of what has been lost. This individual participation is decisive- very much like the general elections in your country. Each citizen is faced with two options- either to stay at home and choose not to vote for a myriad of reasons (usually it’s along the lines of ‘my vote doesn’t matter’) Or to participate in this and make their voices heard. That one little splash may generate a ripple which can have far reaching effects.

I would like to conclude this series, on Nature and Nurture, by enumerating a few more activities which would not only instill an awareness of nature and environmental issues, but also create a supportive attitude. None of these activities are restricted to your home- the same can be practiced at your school, university, workplace, or clubs.

a. The idiot box, that spring of all temptation and lethargy, is the unlikely hero, being the source of nature and wildlife channels such as Animal Planet, Discovery, and National Geographic, all of which air informative programmes on an array of areas pertaining to nature and the environment. Apart from broadening your horizons, these can provide a visual glimpse into the vast world beyond the confines of our cities and districts. And should one intend to pursue a career in the life and physical sciences, this early training would be useful.
Whilst it was only in 1996 that we subscribed to satellite TV and its extensive assortment of channels, our childhood featured us watching David Attenborough’s programmes and other wildlife documentaries, which have, doubtless, left a great mark upon us.

b. By opting for green technologies and energy supplies (including solar), one does more than doing their little bit for the environment. Another tip would be to make the maximum utilisation of natural sunlight – why switch on the lamps during daytime when the sun is much more luminous?

c. Recycling (as well as reducing unnecessary wastage) and Reusing could be encouraged. Furthermore, purchasing recycled materials, such as stationery, helps these green innovators and can also encourage the need to prevent harm to the environment. It is possible that you may already have such green initiatives in your town. If not, why not start these and encourage others to participate as well?

d. Reducing the amount of plastics used in the household. Also, a good shopping bag can easily accommodate all the groceries and reduce the usage of plastic bags which are so freely distributed by the retailers.

e. Instead of juicy gossips dominating the living room tête-à-tête, one could stimulate a fruitful and illuminating discussion by referring to environmental issues or discussing such recent reports.

f. A plethora of magazines are published the field of nature and the environment. For the novice, there are Birds and Bloom, Scientific American, and National Geographic. For the curious, New Scientist, Nature, and Science. For the professional, just too many to list down here. Reading these and adding these in your library or in the foyer can result in some amount of eye-opening!

g. Schools, universities, and workplaces have in-house magazines which certainly will be read by the current students/employees, the alumni, and (potentially) their family members. By publishing articles in these magazines, you will be reaching a wider audience. Encouraging the children to participate in such activities at their school will reap benefits as well.

h. And here’s one of my favourite activities: one often gets invited to birthday parties and many other occasions which requires celebrations. Why not give a plant (or some seeds) as a gift? Alternatively, you could gift them with a membership to a nature/environment organisation!

i. And why take the car when you can easily walk to a site/work/school? Good for health and good for the environment!

j. There are numerous other possibilities, but these require some degree of leaving the comfortable confines of your home and enjoying nature where it can be enjoyed best- the outdoors.
The possibilities are numerous: a visit to the zoo, weekend exploration of the countryside and nearby forests, ecotourism options, just to state a few. Furthermore, all of these can be garnished with hiking, biking, and (for the more adventurous) camping! And for those with tight purse-strings, these activities are all very affordable. After all, nature doesn’t come with a price tag.

I am very certain that I have overlooked other points relating to Nature and Nurture. If the readers have such suggestions, I will be very grateful if you could list them via the comments. I shall, then, incorporate these into another post. But WWF-India and AboutmyPlanet.com have a great list of tips for those who are interested in getting more tips on how to be green.

Parents tend to be the role-models of the children. Your behaviour and attitudes leave a lasting impact on them. So, if you tend to have a green outlook (although I would eschew anything too extreme!), it is likely that your children would be inspired to be like you as well.

And what do parents get out of this? Happiness, cohesiveness, and knowing that there’s one more environmentally responsible child, who, in turn, would inspire many others. After all, it is each individual choice which determines the nature of future policies. .