Bags of trouble

Although these issues grab the headlines, sometimes it is the less-heralded issues that highlight how we as a collective society take convenience for granted at the expense of the environment.

Take the emergence of the bagged salad.

I remember the controversy that accompanied its introduction in the early 1990s and yet the bagged salad market now accounts for well over 1.25 billion each year.

Let's start with the obvious; is it natural to be eating salad in the depths of winter?

Older readers will remember that before it was "normal" to eat salad in January, most people lived on brassicas (cabbage, sprouts, cauliflower, etc.,) or root vegetables.

The invention of bagged salad revolutionised the way in which lettuce could be transported since it substantially increased its shelf-life.

This enabled lettuce to be transported by air-freight around the globe all year round.

Your bag of salad is now more likely to come from Kenya than a local producer.

When growing salad in countries such as Kenya, more pesticides and water are likely to be used in production than in more forgiving temperate climates.

However, growing in Africa offers the advantage of an all-year round season.

In order to keep the salad leaves young and fresh looking for as long as possible, many are washed in chlorine and then placed in bags where the air inside has been modified to reduce the oxygen content.

Some research has suggested that the effect of this process has been to reduce the nutritional value of the salad compared with whole lettuces.

Interestingly, the market for lettuce has increased by 90 per cent in the last 15 years, while only 20per cent more lettuce is actually grown.

This is due almost entirely because retailers have become cleverer at marketing lettuce.

We actually want someone else to wash it and chop it up for us!

The problem is that lettuce is also now the number one food item thrown away by householders.

Is that another consequence of the bagged salad?