Environmental Monitoring

Previously, we have mentioned studies based on environmental, zoological and ecological analyses, that indicate that animal wildlife is subjected to non-natural effects such as intersex, altered sexual maturation and fertility, estrogenic interference, altered feeding behaviour, altered energy metabolims and fat deposition, even altered courting and mating behaviour.

In some cases, these phenomena have been shown to be the consequence of environmental exposure of animal wildlife to low doses of chemicals of human origin with EDC activity. Exposure is ongoing, possibly for long times. A contribution and influence of climate changes, seasonal drifts, random variations could also be proposed, but chemical interference remains the most logical, measured and demonstrated phenomenon.

You have learned about the substances which may manifest their adverse effect very slow and insidiously. Appropriately used biotests have the potential to detect the unintended effect of these anthropogenic chemicals (week 3 activity 1). For example, organochlorine insecticide (DDT) helped to control malaria and typhus. The discoverer of its properties was even awarded the Nobel Prize in 1948. But, at the turn of the 20th and 21st centuries, when its carcinogenicity properties, chronic toxicity and adverse pregnancy outcome were proven for humans, more than 170 countries restricted agricultural use of DDT (see Stockholm Convention on Persistent Organic Pollutants). Likewise, diethylstilbestrol (DES) was predicted as a beneficial drug for pregnant women, while only years later DES presented its adverse effect on the next generation.

Environmental monitoring and biot-tests help to protect the natural environment from the impact of human activity

Over the years epidemiology has shown the negative effect of DDT or DES on human health, and in parallel, most of the disorders following exposure to xenobiotics were confirmed in animal models. Animal cells are often the first step to identify chemicals with direct toxicological effects, but the reproductive, metabolic, thyroid, cognition, or even social behavior disorders cannot be modeled in cell-based tests. Animal models tend to be more appropriate for identifying EDC effects as well as exploring their mechanism of action.

Studies need to collect samples or to run experiments.

It is evidently impossible to study the effect of every chemical (more than 80,000) on all the plants or animals in their habitat or in the general environment. Thus we need sampling and statistics. Sampling is the process of collecting representative data from selected areas or populations. Because lots of the environmental contaminations are ubiquitous in water, soil, air, or waste sites and they are resistant to biodegradation processes, the measurement of their level in the environment has to be repeated over and over. From this one can obtain information about the ratio between their elimination and accumulation. According to the specifics of a study, the time of day, as well as the season can be also crucial for the reliability of the analysis. You should be aware that mistakes in sampling are inevitably followed by serious errors in scientific analysis and in the final results. Only after the property analyses, measurements or experiments the scientist can judge the effect of chemicals on individual organisms. For example, the stimulatory effect of DDT on uterine contractions. Since DDT has been detected in the blood and placentas of women experiencing spontaneous abortion, it is a good idea to have laboratory scientists cooperate with medical teams, to combine the data from experiments with data on morbidity in an area. From here, the potential health risk of the chemicals can be estimated and the perspective for the population can be predicted. Results must also be published and made available to support the action of governments or institutions. For example, the World Conservation Monitoring Centre at the UNs has been delegated to monitor environmental preservation.