it's quite interesting to read what is actually in disposable nappies, like, what are those blue crystals?

WHAT IS IN A DISPOSABLE?
Super Absorbent Gels
Most disposables contain a super absorbent gel, including sodium polyacrylate crystals, a chemical deemed unsafe and banned from use in tampons in 1985 because of its association with toxic shock syndrome, but approved by the American Food and Drug Administration for use in baby's disposables. As mothers we ought to be very much concerned by the distinct lack of research into the effects of extreme dryness on babies thin skin and genitalia,and fears of these super-absorbent chemicals entering the body through broken skin.

Chlorine Bleaching
Chlorine bleaching is much less prevalent than in earlier days of bleaching wood pulp for white paper product, but many disposables still contain extremely toxic dioxins created by this bleaching. There is much debate over whether there is actually a safe level of dioxins. (Costello A et al 1989 The Sanitary Protection Scandal. The Women's Environment Network)

Polypropylene
The 'cloth like cover' and 'stay dry liner' are usually made of polypropylene, a petrochemical, or petroleum derivative which is non-recyclable and toxic when incinerated. The 'breathable cover' is technically true, but the breathability is so minimal to be of negligible effect, typically less than 3% of total weight evaporated in a 24 hour period. The plastics used in disposable nappies use PCBs in their manufacture, and the waste from this manufacturing is poured out into our rivers and oceans. PCBs are fat soluble, and therefore pass quickly from water to living tissue, and accumulate in the food chain. In otters and minks, the accumulation of PCBs has caused disturbance of the neuro-endocrine system, affecting puberty, ovulation reproduction function, and foetal and neonatal survival.


Airborne Emissions
An independent study conducted by Anderson Laboratories in 1999 showed airborne emissions of some disposable nappies producing acute respiratory toxicity, including asthma like reactions, in laboratory mice. The researchers suggested further research into a possible link between disposable nappies and the increasing prevalence of childhood asthma. Chemical gases such as toluene, xylene, ethyl benzene, styrene and isopropyl benzene have been found to be in air emissions from disposable nappies.

Raised Scrotal Temperatures
Disposable nappies raise temperatures in the genital area, and for boys, elevated scrotal temperature has been suggested as slowing down the development of baby boy's testicles. Wolfgang Sippell, Professor of Pediatrics at the University of Kiel in Germany : ADC -- Sign In Page?This alarming information is based upon the fact that the cells supporting sperm production are laid down in the first two years of life and this development is dependent upon temperature. Testicles need to be cooler than the rest of the body so that is why they are external. Studies over the last twenty five years have shown sperm counts to have fallen as fast as 2 per cent per year. Other factors can play a part in these figures but evidence suggests that use of disposable nappies could be a contributing factor. There is no doubt that disposable nappies trap the heat-especially in the height of summer-and there is concern about the long term effect this could have on both sexes, apart from being most uncomfortable? http://natnap.port5.com/press_1.html

Disease Transmission through Faeces
A potentially serious problem associated with disposable nappies is the ease of disease transmission via faeces left on the nappy and then disposed of in regular household waste. More than 100 enteric viruses are excreted in human faeces, including hepatitis and polio (the live vaccine is used for immunization). Viruses can live for months creating risks to both sanitation workers and contamination of groundwater in landfills? ( Primomo J et al (1990) The high environmental cost of disposable diapers, Journal of Maternal and Child Nursing, 15 (5) 279-84)
How many parents do you know who actually scrape poo off a disposable into the loo? The safe thing to do, put toilet waste, down the toilet.