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Fluoride water testing: Dental fluorosis

Fluoride water testing: Dental fluorosis

Fluoride comes from fluorine which is a natural and abundant element. It can be found naturally in water, soil and foods.1,2,3 Fluoride can also be also be found synthetically in water, toothpaste and mouth washes.2,4 Water authorities may also add fluoride to municipal water supply because it has been proven that adding fluoride in areas where fluoride water levels are low can reduce the prevalence of tooth decay to the local population.2,3,5

While low level of fluoride helps to strengthen teeth and protect enamel, too much fluoride can cause dental fluorosis – a discoloration of teeth.1,6 In this condition, fluoride collects in developing teeth, preventing enamel from forming normally. This can cause permanent tooth staining.7,8,9 Dental fluorosis occurs when children between birth and 9 years of age are exposed to high levels of fluoride during critical window when their teeth are forming and can also increase risk of tooth decay. 7,8,9,10

Facts about fluoride

  • Once inside the body, fluorides are absorbed into the blood through the digestive tract. They travel through blood and tend to accumulate in areas high in calcium such as bones and teeth.
  • Adding fluoride to water supply reduces incidences of tooth decay/cavities by promoting mineralization and making tooth enamel more resistant to acids.
  • However, excessive fluoride exposure can lead to dental fluorosis or skeletal fluorosis which can damage joints and bones.
  • A fluoride level of 7 ppm is considered the best for dental health and a concentration that is above 4.0 ppm can be hazardous.
  • The EPA has set a drinking water standard of fluoride level of between 7 and 1.2 ppm to help protect younger children from dental fluorosis.3,4,5,9

The benefits of fluoride levels in water within the recommended concentration clearly outweigh the risks. But given how common dental fluorosis occurs, it is important to regularly and frequently test our water (some of which include tap water, borehole water, river water, well water, lake water, municipal water, water from filtration plants and bottled water) to protect our population; especially children from preventable dental fluorosis.6,7,9,10 It is important to determine fluoride concentration in drinking water and comparing with acceptable levels to prevent dental fluorosis.

Fluoride water testing from CSI International Ltd

CSI Laboratory Ltd is your all-in-one consultant laboratory for your water analysis needs. We have our presence in Nairobi, Kenya. Our laboratory, accredited by the Kenya Accreditation Service (Laboratory Number: KENAS/TL/48), has a well-equipped chemistry laboratory with the latest analytical techniques and experienced technical team able to effectively assess water fluoride levels for both domestic and commercial purposes.

Our fluoride water testing services include: borehole water, domestic tap water, municipal water, well/spring water, bottled water, water from filtration plants and water for medical purposes. In addition to this, we provide regular monitoring of fluoride water levels in your water supply system and compare it to EPA acceptable limits to protect your household and consumers from excessive fluoride exposure. After analysis, we provide you with a detailed fluoride water testing report that allows you to inspire confidence in your water, enhance productivity and enable you to gain faster access to both local and international markets.

Contact us for Fluoride water testing needs. We aim to provide our unwavering support in Kenya and across the world.





Water Analysis - Microbial Testing of Water

Water Analysis - Microbial Testing of Water

Microbial Testing of Water

Facts about water

Water is one of the most important resources found on earth.1 In similar regard, ‘Pure water is considered as the worlds’ first and foremost Medicine’ since the quality and quantity of water we drink has a direct impact on our immune system. In the last century, water use has grown at more than twice the rate of population increase.2 According to the current statistics, 80% of all illness in the developing world is water related and consumption of unsafe water kills 200 children every hour.3,4

But do you know that the water we consume and use in industrial formulation of products could be contaminated with disease causing microorganisms? 

Microbial Water Contamination

Microbial water contaminants namely bacteria, viruses and parasites are considered as a major contributor of several preventable water borne diseases such as cholera, diarrhea, typhoid, dysentery and polio.5,6,7 These microbial contaminants can get to our water systems through discharge from water treatment plants, hospitals, agricultural waste, sewer systems and industrial effluents.5 Microbial water testing and regular monitoring of our water systems helps to estimate the number of microorganisms present and allows the recovery of microorganisms in order to identify them.6 From this data, the quality of water can be verified and quick interventions imposed. Consequently, microbial water testing and regular monitoring helps to ensure the water provided is safe and free from disease causing organisms.5,7,8

Microbial water testing and monitoring programmes

Indicator Microorganism

Pathogenic microorganisms mainly bacteria, viruses and parasites are mainly associated with fecal waste.6,9,10 Direct/individual testing and monitoring of all the pathogenic micro-organisms is considered difficult and a nearly impossible adventure.9  This is because, microbial pathogens are many, they are shed into our water inconsistently and they tend to be found in very low concentrations in water.9,11 Instead selected ‘Indicator microorganisms’ are used to ascertain the presence of pathogenic microbial organism in water. The presence of indicator microorganisms in water can therefore be used to identify a potential health hazard, recognize a contamination source and evaluate the effectiveness of water contamination risk reduction actions.12 The most common indicator microorganisms - fecal coliforms, enterococci, total coliforms and E.coli - are those microorganisms that are normally prevalent in the intestines and feacal matter of warm-blooded animals.9,11,12 In microbial water testing and monitoring the presence of indicator microorganisms beyond a certain established limit indicates contamination of water with pathogens and water quality deterioration.

Culture Media

In this method, selective media have been developed for the detection of different microbial water contaminants. Pseudomonas aeruginosa can be detected using Pseudomonas agar, Coliforms and E. coli can be detected using membrane lauryl sulphate agar/broth, enterococci can be detected using membrane enterococcus agar.13,14 The media allows the colony to grow so that they become visible to the naked eye. To ensure an appropriate number of colonies is generated and statistically interpreted several dilutions of the water sample are usually cultured from the original water sample.15 

Growth in the respective media acts as an indicator of the presence of the microorganisms. Further culturing can then be done to confirm the identity of the suspect colonies in the selective media.13,15,16

Membrane Filtration

In membrane filtration method, the water sample is passed through a membrane filter of 0.45 µm, the filter is then asceptically transferred into agar plate and membrane is incubated.13,16,17. The microbial cells that are trapped in the membrane will grow into colonies that can be counted and microbial density of the water samples calculated. Using this technique, very low microbial presence can be detected since large volume of water sample can be filtered.17

CSI Laboratory for your microbial water testing and monitoring needs

At CSI Laboratory, a consolidated microbial water testing programme; culture media, membrane filtration and indicator microorganism is implemented to analyze the presence of pathogenic microorganism including staphylococci, Escherichia coli, fecal coliforms, fecal enterococci and Pseudomonas aeruginosa.

We carry out short and long term microbial testing and monitoring of water from manufacturing units, retail outlet, food processing units, hospitals and food outlets. We also provide services for microbial water analysis for regulatory approval certification, environmental assessment programs as well as research.

We have our presence in Nairobi, Kenya and our laboratory is accredited by the Kenya Accreditation Service (Laboratory Number: KENAS/TL/48). We aim to provide our unwavering support in Kenya and across the world.

Contact us for your microbial water testing and monitoring needs in our state of the art facility. Sample collection is at your own convenience. Our personnel can visit to collect the samples for microbial water testing. Subsequently, we provide a complete report covering the essential analysis parameters




















Environmental Monitoring

Environmental Monitoring

Stack Emission Monitoring


Air is essential to life. It is the fundamental building block, apart from which life itself would not exist. Poor air quality is a great environmental risk to human health. Some of the common pollutants include particulate matter, Carbon dioxide (CO2), carbon monoxide (CO), Oxides of nitrogen (NOx) and Sulphur dioxide (SO2) Hydrocarbons (CxHy) and volatile organic compounds (VOCs) and ozone. Over a short period of time, exposure to the poor air quality causes an increased risk of heart disease, wheezing, coughing, and respiratory problems and skin, nose, and throat irritation. Chronic exposure causes respiratory diseases such as asthma, cardiovascular diseases and premature death. Lead exposure is linked poor brain development and thus reduces IQ in children. In Kenya, air pollution accounts for approximately 19000 premature deaths according to The State of the Global Air 2019 report. Apart from human health, pollutants such as sulphur dioxide and nitrogen oxides in air cause the formation of acid rain which damages buildings and cultural monuments, causes leaching of nutrients from the soil thus affecting agriculture and changes the composition of water bodies thus affecting aquatic life. Carbon dioxide, ozone and methane are known greenhouse gases which are responsible for global warming and climate change.

Forms of air quality

  1. Ambient air quality measurement

Ambient air pollution describes air pollution in outdoor environments. Poor ambient air quality occurs when pollutants reach high enough concentrations to affect human health and/or the environment.

Ambient air quality measurement is where the pollutant levels in the ambient atmosphere are measured.

  1. Stack emission monitoring

Stack emission monitoring also referred to as stack sampling, stack emission testing or source emission monitoring is the regular air monitoring of an emission point from industrial processes or plants.1,2 Where emission levels from an industrial process exceeds the set limits in permits and licenses this is considered a non-conformance. Therefore, with a reliable stack emission monitoring system, the relevant authorities monitoring the emission are able to take the necessary real-time action to ensure the emission parameters are within limits.

What is a stack?

Stacks are essentially large industrial chimneys that emit hot air, pollutants and particulate matter into the atmosphere at such a height that they do not cause danger to individual on ground. The pollutants emitted in the stacks could be in form of solid, liquid or gaseous state and include particles, dust, solvents and gases [Hydrocarbons, methane (CH4), CO2, carbon monoxide (CO), Oxides of nitrogen (NOX) and Oxides of Sulphur (SO2)]. If these emissions are not regulated they can have a detrimental effect on air quality.

Reasons for carrying out stack emission monitoring

  • Collect data for environmental impact assessment.
  • Assess the performance of pollution control devices.
  • Assess the process efficiency and process control.
  • To ensure compliance with environmental legislation

Approaches to monitoring stack emissions

Periodic measurements

In this approach, stack emission testing measurements are carried out periodically such as once in four months. Samples are withdrawn from the stack and either analyzed off-site or on-site using a transportable measuring system. Using this periodic stack emission monitoring approach, it does not allow concerned persons to take necessary action when required.4

Continuous measurements

Continuous stack emission monitoring on the other hand, involves automatic continuous monitoring of stacks enabling plant managers to monitor emission levels in real-time.1,4 While using this approach, whenever emission parameters exceeds permissible limits, the relevant authorities are able to take the necessary corrective action on time to ensure that parameters are within limits.

Stack emission monitoring from CSI International Ltd

Monitoring stack emissions is important in fulfilling your regulatory process control requirements. At CSI International Ltd we are able to carry out stack emission monitoring of all type of stacks from both small and large industrial plants. Our stack emission monitors include flow monitors, gas monitors and dust monitors. Our highly qualified technical team has a wealth of experience in undertaking this work to deliver a complete stack emission monitoring service to support your industry in fulfilling its regulatory requirements as per the Environmental Permitting Regulations.

We have our presence in Nairobi, Kenya and our laboratory is accredited by the Kenya Accreditation Service (Laboratory Number: KENAS/TL/48). CSI International Ltd has had its accreditation from 2017 allowing it to successfully complete stack monitoring testing using the most appropriate methods and analysis equipment. Depending on our client’s preference, we are able to offer either periodic measurements or continuous monitoring of stack emission to monitor a wide range of regulated pollutants including; Volatile organic compounds, particulate matter, metals, acid gases, hydrocarbons, metals and gases (such as O2, SO2, CO2, NOX and CO).

We aim to provide our unwavering support in Kenya and across the world.

CSI laboratory offers both stack emission monitoring and Ambient air quality measurement services to ensure our clients meet their environmental protection regulatory requirements

Contact us for your stack emission monitoring needs.


  1. What is Stack Emission Monitoring? - Machine Applications Corporation (
  2. Basic Information about Air Emissions Monitoring | US EPA
  3. Monitoring stack emissions: techniques and standards for periodic monitoring - GOV.UK (
  4. Stack Emission Monitoring | Logic Ladder


Food Toxicology

Food Toxicology

Food safety and toxicology

Food can contain a large number of natural, chemical and synthetic toxic compounds that if consumed can present a food safety problem with immense negative effect.1 Food safety and toxicology is concerned with the use of scientific techniques in assessing the presence of these toxic compounds in food and their detrimental effects on living systems.2,3

Some of these toxic compounds can be naturally found in food as toxins (e.g., micro-organisms) or deliberately added to food during processing as dyes, preservatives etc.2 Other substances however, can be accidentally present themselves in food as a result of environmental pollution (metals, pesticide residue, drugs, industrial waste etc.), packaging material or contaminants originating with processing machinery.3,4

Currently, as the food industry and supply chain continue to become more multinational in nature, any contamination can cause serious, irreparable and widespread adverse health effects.4,5,6

This highlights the urgent need for regular testing of food before entering the food chain.

Food safety and toxicology from CSI International Ltd

CSI Laboratory Ltd is your all-in-one consultant laboratory for your Food safety and toxicology analysis. We have our presence in Nairobi, Kenya. Our laboratory, accredited by the Kenya Accreditation Service (Laboratory Number: KENAS/TL/48), has a well-equipped chemistry and microbial testing laboratory with the latest analytical techniques and experienced technical team able to effectively assess the presence of toxic compounds - such as (microorganisms, metals, pesticide residue, drugs and industrial chemicals) - in food meant for domestic and commercial consumption.

In addition to this, since novel foods must also undergo analysis to provide relevant data on the composition, uses and consumption before approval by relevant regulatory body; we extend our services to novel food analysis meant for regulatory approval purposes. To ensure that trade continues, we as well provide food safety and toxicology analysis services for export-import licenses issuance and advice accordingly depending on different target market regulations.

We aim to provide our unwavering support in Kenya and across the world.

Contact us for your food safety and toxicology needs.




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CSI International Limited,
Howse & McGeorge Centre
Building No. 10, Factory Street,
Industrial Area, Near Rocky Driving School
P.O Box 47846-00100,
Nairobi, Kenya