Poor Management of Chemical Inputs
Environmental Assessment: Pressure State Response Indicators

The main problems stem from the contamination of wastewater with organic and in-organic chemicals and the presence of residual feed supplements in animal wastes. These are transferred to the land through the use of wastewater as an irrigation source and the use of treated and untreated manure as a fertiliser. | Pressure State Response

There are additional problems with the excretion of drug residues - and active drugs in manure and wastewater, which impact on soil and aquatic life.

Although there are generally regulations covering the treatment and disposal of heavy metals and other pollutants in domestic sewage, in many cases these regulations do not apply to "farm" waste.

The impact of toxic levels of trace elements includes damage to plant growth and damage to aquatic systems. At high levels there are direct links to human health problems. Pesticides, bactericides and other sanitation products discharged with effluents will also damage beneficial organisms in the natural environment.

The excessive use of microbial products can also have negative effects on natural systems.

Pressure

Chemical wastes from animal production systems are generally no different from those produced by many other industries or from domestic waste. However, the concentration of these activities and the disposal of wastes in localised areas can result in major environmental and environmental health problems.

Pressure is characterised by:

- The type of enterprise, pig, poultry, ruminant or dairy;
- The scale of the enterprise - small, medium or large;
- The technology used - type and quantity of supplements, type and application of pesticides, fungicides, bactericides, rodenticides;
- The type and frequency of drug use as prophylactics and to control disease outbreaks;
- The methods used for waste disposal - including on site treatment, disposal of sludge, land fill and effluent discharge into open water and sewage systems.

Again it is the incremental effect of the enterprise on top of other activities that produce similar contaminants in effluents that is of concern. Technologies and management strategies are available to minimise risks of pollution, through both reduction in the use of inputs, use of alternative, low polluting hygiene practices, pre-treatment of wastes and discharge into non-sensitive environments.

State

There area an estimated 1 million human pesticide poisoning cases each year in the world, with about 20,000 deaths, mostly in developing countries. The problem is rendered even more difficult because few, if any, new compounds are coming to replace old insecticides. The cost of developing and registering new pesticides is staggering almost US$ 60 million, and pesticide manufacturers are unwilling to risk investments on products whose market life could be shortened by development of pest resistance.

The impact on the environment is through build-up of toxic chemicals and residual drugs from waste products, and the destruction of natural systems through the effects of released pesticides, bactericides and other inputs.

The impact is therefore a change in the terrestrial and aquatic ecosystems. This may well extend to impacts on crop land and other managed systems into which effluent is discharged. Considerable concerns have been raised on impacts on environmental health, both direct through contamination of water supplies and through consumption of contaminated animal and vegetable products.

Direct state indicators include:

- Changes in indicator species - both loss of species and increase in invasive species;
- Changes in habitat;
- Localised poisoning - such as fish death;
- Build up of trace elements and other compounds in food chains, and in body tissues.
- Development of pesticide resistance

However, more commonly the state will be characterised by concentrations of chemicals and other pollutants in effluents, based on set emission standards. These can be measured at source or at outflow.

Response

Most industrial animal production activities are governed by local regulations, and these may also apply to the use of chemicals in Grazning and Mixed production systems.. These regulations will cover aspects from site planning to sanitation and the handling and disposal of pesticides and farm medical wastes. The effectiveness of existing regulations and enforcement of regulations has recently been questioned, particularly with respect to environmental health issues. Again it must be emphasised that one of the problems is the issue of scale. Many intensive industrial systems still fall under regulations designed to deal with extensive farm systems.

Pest control, as practiced today in most developing countries relies mainly on the use of imported pesticides. This dependence has to be reduced. Although pesticides are generally profitable on direct returns basis (used on crops and/or livestock), their use often leads to the contamination of terrestrial and aquatic environments, damage to beneficial insects and wild biota, accidental poisoning of humans and livestock, and the twin problems of pest resistance and resurgence.

The two approaches to regulation can be characterised as follows:

- Specification of acceptable levels of discharge for listed pollutants, implying that non-listed pollutants are acceptable; or
- Specification for acceptable levels of discharge of pollutants, implying that only those pollutants specified may be discharged.

Either way regulation relies on defining "acceptable levels". However, this will vary according to the total number of enterprises undertaken within the catchment, and the characteristics of the catchment. Regulation will therefore have to be subject to ammendment as the impact of acceptable discharges are monitored within the water body and on the land - evaluated by the State Indicators.

Response is characterised by:

- Regulations, and ammendment of regulations to specific local requirements;
- Specification of acceptable technologies;
- Monitoring effort by regualting agencies;
- Prosecution or other interventions by regulatory agencies.

Further Reading

Use of Pour-on Technology as Prophylactic to control insect-borne disease vectors

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