Air and water quality are fundamental to human health and the environment. Clean air and water are not just basic necessities; they are crucial for the well-being of all living organisms. Poor air and water quality can lead to a wide range of health problems, from respiratory diseases to cardiovascular conditions, and can even contribute to long-term environmental damage. As global pollution levels continue to rise, it has become increasingly important to monitor the quality of the air we breathe and the water we drink.
Understanding Air Quality
Air quality refers to the cleanliness of the air around us, especially air that is free of harmful pollutants. Some of the major air pollutants include:
- Particulate matter (PM): Tiny particles (such as PM2.5 and PM10) that can travel deep into the lungs and even into the bloodstream.
- Ground-level ozone (O₃): Ozone formed when pollutants react with sunlight, this ozone can cause respiratory problems.
- Nitrogen dioxide (NO₂): Gases from vehicle emissions and industrial emissions that can damage lung tissue.
Understanding Water Quality
Water quality refers to the physical, chemical, and biological characteristics of water that determine its suitability for drinking, recreational, and agricultural use, as well as for maintaining aquatic ecosystems. Common water contaminants include:
- Pathogens: Bacteria, viruses, and parasites that cause infectious diseases such as cholera and diarrhea.
- Chemical contaminants: Industrial chemicals, pesticides, and heavy metals such as lead and mercury.
- Excess nutrients: Nitrogen and phosphorus from fertilizers, which can lead to eutrophication, algae outbreaks, and lack of oxygen in the water.
Impacts of air and water pollution
Air and water pollution are not just separate issues; they are interrelated and can exacerbate each other. Example:
- Acid rain: Air pollutants such as sulfur dioxide and nitrogen oxides emitted into a body of water can lower the pH of the water and harm aquatic life.
- Haze: Airborne pollutants may settle into water bodies and contaminate water sources.
The consequences of air and water pollution are far-reaching:
- Public health crisis: Increased hospitalization rates, shorter life expectancy, higher medical costs.
- Economic losses: Reduced agricultural productivity, impaired tourism, and higher water treatment costs.
- Environmental degradation: loss of biodiversity and destruction of natural ecosystems.
How to Monitor Air Quality
Air quality monitoring focuses on measuring the concentration of various pollutants in the air to determine if the air is safe and healthy. Common air quality monitoring methods include:
Air Quality Index (AQI)
The Air Quality Index (AQI) is a simple and easy-to-understand index to indicate air quality. It is calculated by monitoring the concentrations of the following major pollutants:
- Fine particulate matter (PM2.5 and PM10)
- Ozone (O₃)
- Nitrogen dioxide (NO₂)
- Sulfur dioxide (SO₂)
- Carbon monoxide (CO)
The AQI usually ranges from 0 to 500, with higher values indicating more severe air pollution and greater health risks. The World Health Organization (WHO) and national environmental protection departments provide appropriate health advice based on the AQI.
Portable Air Quality Detectors
For personal or small area monitoring, portable air quality detectors are a handy tool. They are able to measure indicators such as PM2.5, carbon dioxide, temperature, humidity, etc. and display the data in real time via a smartphone app. Common brands such as PurpleAir and Awair.
Automatic Monitoring Stations
Automatic monitoring stations are often deployed by governments and environmental organizations to monitor and record airborne pollutant levels in real time. These monitoring stations usually cover an entire city or a specific area, and the data is publicly accessible for early warning and policy making.
Satellite Remote Sensing Monitoring
Using satellite remote sensing technology, scientists can monitor air pollution on a global scale from space. For example, NASA and the European Union’s Copernicus program provide real-time data on global air quality to help researchers analyze large-scale air pollution trends.
How to Monitor Water Quality
Water quality monitoring, on the other hand, assesses the suitability of a body of water for drinking, agricultural irrigation, and ecological habitat by measuring physical, chemical, and biological indicators in the water. Common water quality monitoring methods include:
pH Measurement
pH is an important measure of the acidity or alkalinity of a body of water. The normal pH for most bodies of water should be between 6.5 and 8.5. If the pH is too low (acidic) or too high (alkaline), it may indicate that the water body is contaminated or affected by excessive chemicals.
Dissolved Oxygen (DO) Measurement
Dissolved oxygen is the amount of oxygen in the water that is available for aquatic organisms to breathe. Low levels of DO in a body of water can lead to the death of fish and other aquatic organisms. Commonly used DO measurement methods include electrochemical sensor methods and optical sensor methods.
Detection of Contaminants in Water
Various pollutants may be present in water, including heavy metals (e.g., lead, mercury), organics, pesticides, and drug residues. Common water quality testing techniques are:
- Spectral analysis: by measuring the light absorption characteristics of water to identify specific pollutants.
- Chromatography: Used to separate and detect the chemical composition of water.
- Biomonitoring: Indirectly determine water quality by observing the health of organisms in the water (such as algae, fish, etc.).
Portable Water Quality Tester
Similar to air quality testing, there are portable water quality testers on the market that can quickly measure a number of parameters such as pH, dissolved oxygen, turbidity, ammonia and nitrogen in a body of water. For home or small-scale environmental monitoring, portable testers are very practical.
Automatic Water Quality Monitoring Station
Similar to automated air quality monitoring stations, many cities and water utilities deploy automated water quality monitoring stations. These stations are able to collect a variety of physicochemical indicators of the water body in real time, and automatically send data reports for decision-making and early warning.
Remote Sensing Monitoring of Water Quality
Through satellite remote sensing technology, researchers can monitor the pollution of water bodies on a large scale, especially in lakes, rivers or oceans, water quality changes. Remote sensing technology is able to detect temperature, algae concentration, sediment concentration, etc. at the water surface in order to assess the health of water bodies.
Air and Water Quality Standard Values
Air Quality Standards
| Pollutant | Standard Values (World Health Organization/China/US EPA) |
| PM2.5 (Fine Particulate Matter) | WHO: 24-hour average ≤ 25 µg/m³; Annual average ≤ 10 µg/m³ |
| China: 24-hour average ≤ 75 µg/m³; Annual average ≤ 35 µg/m³ | |
| US EPA: 24-hour average ≤ 35 µg/m³; Annual average ≤ 12 µg/m³ | |
| PM10 (Inhalable Particulate Matter) | WHO: 24-hour average ≤ 50 µg/m³; Annual average ≤ 20 µg/m³ |
| China: 24-hour average ≤ 150 µg/m³; Annual average ≤ 70 µg/m³ | |
| US EPA: 24-hour average ≤ 150 µg/m³; Annual average ≤ 50 µg/m³ | |
| Sulfur Dioxide (SO₂) | WHO: 24-hour average ≤ 20 µg/m³ |
| China: 24-hour average ≤ 500 µg/m³; Annual average ≤ 60 µg/m³ | |
| US EPA: 1-hour average ≤ 75 ppb; 24-hour average ≤ 0.14 ppm | |
| Nitrogen Dioxide (NO₂) | WHO: Annual average ≤ 40 µg/m³; 1-hour average ≤ 200 µg/m³ |
| China: Annual average ≤ 60 µg/m³; 24-hour average ≤ 150 µg/m³ | |
| US EPA: Annual average ≤ 53 ppb; 1-hour average ≤ 100 ppb | |
| Carbon Monoxide (CO) | WHO: 8-hour average ≤ 10 mg/m³ |
| China: 8-hour average ≤ 10 mg/m³ | |
| US EPA: 8-hour average ≤ 9 ppm; 1-hour average ≤ 35 ppm | |
| Ozone (O₃) | WHO: 8-hour average ≤ 100 µg/m³ |
| China: 8-hour average ≤ 160 µg/m³; 1-hour average ≤ 180 µg/m³ | |
| US EPA: 8-hour average ≤ 0.070 ppm |
Air Quality Standards
Water Quality Standards
| Water Quality Indicator | Standard Values (World Health Organization/China/US EPA) |
| pH | WHO: 6.5 – 8.5 |
| China: 6.5 – 8.5 | |
| US EPA: 6.5 – 8.5 | |
| Dissolved Oxygen (DO) | WHO: ≥ 5 mg/L |
| China: ≥ 5 mg/L | |
| US EPA: ≥ 5 mg/L | |
| Total Nitrogen (TN) | WHO: ≤ 10 mg/L |
| China: ≤ 10 mg/L | |
| US EPA: ≤ 10 mg/L | |
| Total Phosphorus (TP) | WHO: ≤ 0.1 mg/L |
| China: ≤ 0.1 mg/L | |
| US EPA: ≤ 0.1 mg/L | |
| Ammonia Nitrogen (NH₃-N) | WHO: ≤ 0.5 mg/L |
| China: ≤ 0.5 mg/L | |
| US EPA: ≤ 0.5 mg/L | |
| Heavy Metals (e.g., Lead, Mercury, Cadmium) | WHO: Lead ≤ 0.01 mg/L, Mercury ≤ 0.006 mg/L, Cadmium ≤ 0.003 mg/L |
| China: Lead ≤ 0.01 mg/L, Mercury ≤ 0.002 mg/L, Cadmium ≤ 0.005 mg/L | |
| US EPA: Lead ≤ 0.015 mg/L, Mercury ≤ 0.002 mg/L, Cadmium ≤ 0.005 mg/L | |
| Turbidity | WHO: ≤ 5 NTU |
| China: ≤ 5 NTU | |
| US EPA: ≤ 5 NTU |
Water Quality Standards
Summary
Air and water quality are the lifeblood of our planet, and they affect not only our health, but the health of every ecosystem on the planet. By understanding their importance and taking effective action, we can ensure that future generations will enjoy fresh air and clean water.
Apure offers a wide range of water quality parameter analyzers, flow and level meters, temperature and pressure meters. Please contact us if you need more information.