Manganese Ore Dust from a Public Health Perspective

A hot topic in the Nelson Mandela Bay community is the public outcry against manganese ore storage and handling and their impact on public health safety.

Manganese ore has been a staple export in the region for over forty years, with two main ports in the Eastern Cape (Gqeberha and Ngqura) managing the bulk of overseas shipping. After the Covid 19 pandemic was declared a national state of disaster in 2020, more and more ore was stored in warehouses located in the districts of Markman and Swartkops just outside of Gqeberha in anticipation of trade picking up again once lockdown eased.

Unfortunately, even when trade picked up again, the warehouses kept being used as storage points for manganese ore. Every day, every hour, trucks go in and out of the districts carting massive loads of metal ore. Observers have said that more than 1000 trucks enter and leave over 24 hours during peak months.

The damage these trucks have caused to the roads in these areas is already a major source of anger to the businesses in this area. This is worsened by pollution caused by manganese ore dust that the warehouses and transporters scatter freely throughout the areas. The spilt ore is left on streets and allowed to run off into stormwater drains when it rains.

If you walk down Chrysler Street in Markman Industria, you might want to wear a respirator or face mask. The dust will have you coughing and sneezing in no time. You’ll also be squinting through an almost impossibly thick cloud of dust, trying to see where you’re going and hoping not to fall into the massive potholes and cracks littering the street and pavement. And if you can’t see the street, the 50 or so trucks that speed past to deliver their ore will not see you either.

Markman and Swartkops are not solely industrial areas either. Markman houses a large township close to the ore warehouses where people are exposed to this dust daily. The dust is also a danger to workers whose workplaces are in this area.

People have become increasingly worried about the environmental effects of this dust and its health and safety effects on people working and living in these areas.

This post will focus specifically on the public health aspects of the matter by answering some of the more prevalent questions people want to be answered on the topic.

What is Manganese?

Manganese is one of the most plentiful metals on earth, and most food we eat contains small amounts that are important for our health and physical development. People mine manganese because it can be used to make steel, glass, paints, fungicides, disinfectants, and many other products. It’s also used in several industrial processes, such as cleaning water and as a fuel additive.
Manganese can exist in either an inorganic or organic (bonded to hydrocarbons) form. Inorganic manganese dissolves much more easily in water, which makes it more readily absorbed by our bodies.

Is Manganese Toxic?

Only in very high dosages.
Manganese is a trace element, which means it’s an important mineral in our diets. Manganese is needed for healthy metabolic and developmental functions in plants and animals. We take in much of this through food and water, with grains, beans and some vegetables being the richest mineral content.

It’s important to note that most people only absorb about 2-5 % of all manganese present in food and drinks, and much of this is also removed from our bodies through natural processes over a short period. Foods and drinks high in manganese or contaminated with it are less likely to cause poisoning than other forms of exposure.

Manganese can also enter our bodies through the skin by swimming or applying salves with high metal content. Skin exposure rarely allows for manganese poisoning, as the manganese needs to travel through several layers of cells before it can enter the bloodstream.

However, breathing in metal dust or fumes is a much more accessible route, as the metal particles can diffuse directly through the lungs into the bloodstream. The smaller the dust particles, the more likely they are to enter the deeper parts of the lungs and be taken up by the body. Over time, manganese builds up in organs and accumulates mostly in the brain’s liver and basal ganglia.
Manganese only becomes poisonous or toxic to people depending on two factors: 1) how much they are exposed to it, and 2) how often they are exposed to it.

Sudden and unnatural exposure to large quantities of manganese (e.g. drinking something with very high metal levels) can have a temporary harmful effect. Still, the metal will quickly pass through the body and ease these symptoms.

Long-term exposure to high quantities, on the other hand, has been shown to cause either minor or serious poisoning, with the most serious causes falling under a blanket term called “manganism”.

What are the Symptoms of Manganese Poisoning?

Many of the symptoms of manganese poisoning are linked to neurological effects, such as nerve and muscle damage, muscle weakness, and mental strain. Severe cases can result in manganism, a Parkinson-like disease or illness, with patients developing tremors and poor motor functions. Manganese accumulation in the brain has been shown to cause mental and psychological stress, with many experiencing recurring headaches, hallucinations, schizophrenia, and insomnia. As symptoms will usually worsen over a longer period of exposure, manganese poisoning or manganism can be thought to occur in two distinct phases: early and late phases.

People who experience only early phase symptoms usually work in an area close to or adjacent to where manganese ore is being stored or used in industry. Those who experience late phase symptoms often directly handle or work with the metal, such as in mining or processing occupations. The latter group will experience early symptoms, rapidly progressing to the late phase.

Early phase exposure gives rise to symptoms commonly associated with mental or psychological stress. Additional reported effects include psychosis, mood swings, paranoia, and depression. These conditions can be treated with the potential of recovery as long as the person affected can minimize further exposure to the metal.

Late phase exposure has been linked to the more serious Parkinson’s-like symptoms where a person develops problems with basic motor functions. People can experience difficulty with walking, balance, tremors, slowed speech and poor responsiveness, which can quickly develop into chronic conditions. Additionally, late-phase manganism cannot be treated with existing therapies for similar conditions such as Parkinson’s Disease, with patients remaining unresponsive to treatment.

If given enough time, manganese buildup in the basal ganglia can be lethal. Death from manganese exposure is rare, but there have been many documented cases of people living with chronic illnesses due to occupational exposure to the metal.

An example of this was the 2020 journal article mentioned in our last post. Northern Cape miners exposed to manganese daily had a drastically decreased quality of life due to occupational illness acquired from their work environment.

How Does This Impact Me?

While on the surface, this doesn’t seem like a condition likely to affect your everyday person, it’s important to know if you’re living in an area where exposure to the metal is a general health concern, such as in the city of Gqeberha right now.

It’s also important to realize that the metal ore itself isn’t the only problem. It’s also the industry’s effects on the environment and related public health.

The dust lifted and spread by the ore transporting trucks is the biggest example of this. In one study, the dustfall measured in the Markman area was over 6,400mg/m3 per day, over five times the acceptable limit for industrial areas according to SANS 1929. Dust is a health hazard and, in large enough quantities, can cause all sorts of health complications from inhalation and exposure to the eyes. Temporary and long-term visual impairment is a major concern for people living in highly polluted areas. In addition, constant inhalation of dust particles can irritate the throat and lungs, resulting in respiratory infections and, worse case scenarios, cancer.

As well as physical health concerns, there are also the psychological health and social impacts the industry has on the public.

Areas such as Markman and Swartkops have experienced major structural damage from the constant traffic of overburdened trucks. Roads are littered with potholes and cracks, traffic is congested and difficult to navigate, homes and properties are coated in thick dust, and fewer and fewer people want to work or live in these areas. This creates massive stress on residents, workers and business owners whose quality of life is affected.

From a purely public health perspective, the effect of this industry on the residents of these areas, in particular, is unacceptable, and this is without taking into account the drastic environmental impact the industry is having.

From various observations and studies, the manganese export industry in Gqeberha has been indicated to be in breach of several national and local laws relating to public health, including the National Environmental Management Act (No. 39 of 2004): Air Quality, dust exposure limits according to the Occupational Health and Safety Act (No. 85 of 1993): Hazardous Chemical Agents Regulation as well as bylaws relating to nuisance dust fall and stormwater pollution.

What are the Exposure Limits?

South African regulations do not state an overall maximum tolerable limit for manganese exposure. Still, the recommendation is that people who work with the metal through occupations should not be exposed to more than 0.2mg/m3 within an 8-hour work shift. The USA’s American Conference of Governmental Industrial Hygienists (ACGIH) recommends the same limit over an 8-hour work shift, while the World Health Organization (WHO), in comparison, suggests a limit of 0.15 mg/m3.

In the USA, the maximum permissible exposure limit for manganese is regulated at 5.0 mg/m3 at any given time, which is a good guideline to use for most other countries.

For dust fall, South Africa’s National Ambient Air Quality Standards suggest a maximum exposure limit of 1200 mg/m3 in industrial areas and 600 mg/m3 in residential areas. Any reading above 2400 mg/m3 requires immediate action.


While a study has already proved that the dust fall exposure limits have been in excess in the Markman area, to assess whether or not the manganese exposure maxima have been reached, various site tests would need to be performed to analyse the metal content present in vulnerable waterways, soil and air.

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