Classification of monitoring systems can be based on monitoring methods: monitoring by physico-chemical and biological indicators, remote monitoring.

Chemical monitoring is a system for monitoring the chemical composition of the atmosphere, sediments, surface and groundwater, the waters of the oceans and seas, soils, bottom sediments, vegetation, animals and controlling the dynamics of the spread of chemical pollutants. The global task of chemical monitoring is to determine the actual level of environmental contamination with priority highly toxic ingredients. These include: sulfur dioxide, suspended particles, radionuclides, organochlorine compounds, cadmium compounds, nitrates, nitrites, nitrogen oxides, mercury and its compounds, lead, carbon dioxide, carbon monoxide, hydrocarbons, fluoride compounds, asbestos, arsenic, microtoxins, microbiological pollution.

In recent years, remote monitoring has been widely used - monitoring with the use of aeronautical and space technology equipped with radiometric equipment capable of actively probing objects and recording data.

The scale of exposure is distinguished:

Global - tracking of global processes and phenomena in the Earth's biosphere, including all its environmental components, and warning of emerging extreme situations; Global monitoring is carried out by international organizations: Global Environmental Monitoring System (established in 1974); Global Atmosphere Watch Service; Global Climate Observing System; Global Ocean Observing System;

Basic (background) - tracking of general biospheric, mostly natural phenomena, without imposing on national and regional anthropogenic influences;

Transnational - monitoring of transboundary pollution;

National - monitoring on the scale of an individual state;

Regional - tracking of processes and phenomena within a region where these processes and phenomena can differ both in terms of both natural and anthropogenic impacts from the basic background characteristic of the entire biosphere; Regional monitoring in the Republic of Tatarstan, for example, was established on the basis of Resolution No. 321 of the Cabinet of Ministers of 07.07.1994. About the Unified Environmental Monitoring System of the Republic of Tajikistan; Regional monitoring is carried out by: Ministry of Ecology and Natural Resources of the Republic of Tatarstan, Department for Hydrometeorology and Environmental Monitoring, Department of the Federal Real Estate Cadastre Agency for RT, Ministry of Health of the Republic of Tatarstan, Department for Technological and Environmental Supervision of the Federal Agency for Technological, Environmental and Nuclear Supervision On the protection, control and regulation of the use of hunting animals of the RT, the Inspection for the Protection and Reproduction of Fish Stocks and Regulation aniyu fishing at RT;

local - monitoring the impact of a particular human source;

IMPACT - monitoring regional and local anthropogenic impact in high-risk zones and locations.

26.The Organization for Economic Co-operation and Development (OECD) (French: Organization de coopération et de développement économiques, OCDE) is an intergovernmental economic organization with 35 member countries, founded in 1960 to stimulate economic progress and world trade. It is a forum of countries describing themselves as committed to democracy and the market economy, providing a platform to compare policy experiences, seeking answers to common problems, identify good practices and coordinate domestic and international policies of its members. Most OECD members are high-income economies with a very high Human Development Index (HDI) and are regarded as developed countries. OECD is an official United Nations Observer. In 1948, the OECD originated as the Organization for European Economic Co-operation (OEEC),^[2] led by Robert Marjolin of France, to help administer the Marshall Plan (which was rejected by the Soviet Union and its satellite states). This would be achieved by allocating American financial aid and implementing economic programs for the reconstruction of Europe after World War II. (Similar reconstruction aid was sent to the war-torn Republic of China and post-war Korea, but not under the name "Marshall Plan".) In 1961, the OEEC was reformed into the Organization for Economic Co-operation and Development by the Convention on the Organization for Economic Co-operation and Development and membership was extended to non-European states. The OECD's headquarters are at the Château de la Muette in Paris, France. The OECD is funded by contributions from member states at varying rates. and had a total budget of EUR 363 million in 2015.

Aim. The OECD defines itself as a forum of countries committed to democracy and the market economy, providing a setting to compare policy experiences, seek answers to common problems, identify good practices, and co-ordinate domestic and international policies. Its mandate covers economic, environmental, and social issues. It acts by peer pressure to improve policy and implement "soft law"—non-binding instruments that can occasionally lead to binding treaties. In this work, the OECD cooperates with businesses, with trade unions and with other representatives of civil society. Collaboration at the OECD regarding taxation, for example, has fostered the growth of a global web of bilateral tax treaties.

The OECD promotes policies designed:

· to achieve the highest sustainable economic growth and employment and a rising standard of living in Member countries, while maintaining financial stability, and thus to contribute to the development of the world economy;

· to contribute to sound economic expansion in Member as well as nonmember countries in the process of economic development; and

· to contribute to the expansion of world trade on a multilateral, nondiscriminatory basis in accordance with international obligations.