ABOUT PINK DISEASE
Pink Disease was and still is a very nasty disease with diverse and complex symptoms. The severity and duration of the disease vary. In the English speaking western world, the age of onset is usually between 6-14 months. The most common cause of Pink Disease was teething powders containing mercurous chloride (calomel). The use of mercury in teething powders was prohibited in Australia from 1953-7 (depending on the state). The symptoms of classic Pink Disease for babies and toddlers include:
An itchy, burning rash
Hair pulling and/or loss of hair
Skin that peels off in layers
Teeth loosen and/or fall out
Photophobia (extreme light sensitivity)
Convulsive seizures and petit mal attacks
Muscle weakness and flaccidity (atonia)
Elevated temperature, blood pressure and pulse rate
Digestive problems including loss of weight,loss of appetite, vomiting and constipation
Enlarged lymph glands
Cold, clammy, swollen pink or bluish hands and feet
Low blood sodium level
Scratching and tearing at skin and sucking andchewing of fingers
General excess sensitivity of the skin to touch, temperature, water and UV light
Excess nasal discharge
Abnormal skin and muscle sensations
Ulceration of the gums
Numbness of the extremities
If circulation is really poor in the extremities, gangrene and auto-amputation can occur
The child is restless, irritable, miserable & anxious
Secondary infections particularly to the skin and lungs
The disease typically lasted between 3 months and a year and it sometimes recurred. Although the disease is commonly called Pink Disease because of the swollen, pink hands and feet that are a noticeable feature of the disease, this symptom is not always present. An abortive, less severe form of babyhood Pink Disease also occurs. Pink Disease occurred in older children in Europe because the most common cause was worming preparations containing mercury. The symptoms of Pink Disease in children over the age of 2 are similar to those mentioned above but are nowhere near as dramatic -
· Irritability, failure to gain weight, sleeplessness and lack of energy are the most noticeable symptoms.
· Light sensitivity and the pinkness of the hands and feet are not as noticeable.
· Coldness and moistness of the extremities is evident.
· Lack of muscle tone and high blood pressure are detectable.
· The child becomes listless, doesn’t smile, and doesn’t want to play anymore and may simply sit around and rest all day. The older child can become asocial, talk infrequently and be bad tempered, difficult and even violent.
The loss of muscle tone was so severe that those who were walking at the time they contracted Pink Disease frequently stopped walking. Those who hadn't started to walk tended to start walking later than average.
Although it has been estimated that between 10% and 33% of babies who got the disease died, a higher death rate is suggested by anecdotal evidence. Death was usually the result of secondary infections such as broncho-pneumonia, circulatory collapse, hyponatraemia and very high fever.
The mothers and other care-givers of babies with Pink Disease suffered severe exhaustion from lack of sleep, severe stress and loss of weight. Family life was generally disrupted by the baby's constant crying.
It's generally accepted that chronic exposure to mercury was the cause of Pink Disease together with some other predisposing factor such as hypersensitivity to mercury, a molecular malfunction, or prior illness. The predisposing factor is likely to be genetic or epigenetic. It is estimated that only 1 in 500 babies who were treated with mercury-containing teething powders got Pink Disease. The next section "A Little History" mentions some of the early theories about what caused Pink Disease.
A LITTLE HISTORY
Some Early Theories
Dr. H. Swift, of Adelaide, first recognised Pink Disease when he was a physician at Great Ormond Street Children's Hospital in London in 1885 and described the disease at the Australasian Medical Congress in 1914, calling it "erythroedema". Selter referred to the disease in 1903 as "trophodermatoneurosis". William Snowball of Melbourne described some symptoms of the disease in 1883. Charles Clubbe of Sydney used the term "pink disease" for the condition.
Dr. A. J. Wood of Melbourne detailed the symptomatology of Pink Disease at the Australasian Medical Conference in 1920.
The disease was also described independently by Bilderback in America in 1920, and by Feer in Germany in 1922.
While Pink Disease is the most common name for the Disease now, it also goes by the name acrodynia, Feer's Disease, Swift's Disease, erythroedema, trophodermanatoneurosis.
The symptoms of Pink Disease were well described by the early 1920's and the search for the cause began in earnest.
It's been commented that had any physician seen a Pink Disease baby earlier than about the 1850's they would have immediately recognised the symptoms as those of mercury poisoning because up to that time, mercury was in very common use and the symptoms of mercury poisoning were well known.
The Mercury Theory was first raised in 1922 by J. Zahorsky because the oral changes did not resemble any other disease except for poisoning from mercury or phosphorus. He discovered a history of mercury ingestion in some of the children, but not in others. He therefore eliminated mercury as a possible cause of Pink Disease. The mercury hypothesis was later retested by Warkany and Hubbard. Warkany's and Hubbard's theory is detailed below.
Others, including Byfield, Vipond, and Rodda suspected that viral infection caused the disease. Rocaz concluded it was an inflammation of the nervous system and Littlejohn considered an infection involving the nervous system, particularly the vasomotor centres in the medulla and spinal cord might be the cause.
Despite studying cultures of bodily fluid and blood, Penfold, Butler, Wood and Gareau found no evidence of viral infection.
Mercury poisoning can cause blood disorders such as anaemia and another theory of Pink Disease was that it was caused by a vitamin deficiency - particularly of the B-Group vitamins. This theory was discarded because most the children who had Pink Disease were well fed and well cared for children. Children in countries with a low standard of living, where deficiency diseases were more common, did not get Pink Disease.
Another theory was that Pink Disease was caused by a dysfunction of the Autonomic Nervous System or that it related to an encephalic lesion because many of the symptoms of Pink Disease were suggestive of this.
Arsenic poisoning and poisoning from contaminated bread were also put forward as theories.
One of the reasons why there were so many theories about the cause of Pink Disease was that the symptoms of the disease were so diverse and were similar to the symptoms that could be caused by various infections, vitamin deficiencies, poisoning and so forth. Looking back, it seems obvious that the cause MUST have been something that could cause a myriad of unpleasant and sometimes deadly symptoms.
Two theories are discussed in more detail below. They are Warkany's and Hubbard's mercury theory that relates to what "caused" Pink Disease, and Cheek's and Hicks' theory which relates to the physiology of Pink Disease. Both the theories and methods of studying them had problems but fortunately; fate stepped in and proved that mercury was the catalyst for PD. Unfortunately, this meant that all research into the physiology of the Disease and the long-term side effects virtually ceased. This is why the Pink Disease Support Group has been collecting and collating information from both Pink Disease sufferers and an age/gender matched control group over the last 20 years.
The Mercury Theory
As stated earlier, Dr. Zahorsky discarded his hypothesis that mercury may have caused Pink Disease because he had been unable to find evidence of mercury exposure in many of his patients.
Dr. J. Warkany had noticed the resemblance of Pink Disease to arsenic and thallium poisoning and in 1945, he requested qualitative metal determinations for blood and urine samples from a child with the disease from the Cincinnati Kettering Laboratory. Mr. Donald Hubbard, a chemist with that Laboratory, had devised a reliable method for determining the amount of mercury found in urine.
Although the child from whom the blood and urine samples came had no history of mercury exposure, a significant amount of mercury was found in the child's urine sample. No other heavy metals were found in abnormal quantities in the child's blood or urine. This, of course, did not prove that mercury had caused the child's Pink Disease. Dr. Warkany therefore collected 189 urine samples from children with Pink Disease over the next four years. Of those samples, 120 or 63.5% had mercury in their urine. In cases where there was no mercury in the urine, a history of mercury ingestion was found. This demonstrated that mercury exposure had occurred in all of the children with Pink Disease. Only 2 of the 87 (2.3%) control group children had mercury in their urine. At the time, the evidence that mercury caused Pink Disease looked extremely convincing.
A major flaw in Dr. Warkany's experimental method was not noticed immediately. In different areas, mercury exposure is different. Some areas used mercury teething powders. Other areas had a lot of mercury because of industrial or agricultural use. Warkany's control group came from Cincinnati where mercury was not freely used and therefore significant levels of mercury in the urine would be unlikely. His Pink Disease samples came from areas where mercury use was common. In 1951, Dr. James of London tested 11 Pink Disease patients and found significant amounts of mercury in their urine. Dr. James' control group was from the same area and he found that they also had significant amounts of mercury in their urine. If the flaw in Warkany's methodology had been noticed straight away, then given Dr. James' results, the view that mercury caused Pink Disease would have been discarded once again.
Fortunately, the idea that mercury was the cause of Pink Disease had already taken hold in some quarters and as early as 1953, mercury had been banned from teething powders in parts of Australia. In England itself, after Warkany's theory was published, it was less common for teething powder to be prescribed by doctors, chemists and child care nurses. The result was the incidence of Pink Disease started to drop dramatically. By the late 1950's, mercury (in the large amounts found in some teething powders) had been banned or removed from most baby products. Pink Disease is now virtually extinct as a disease and has been since the late 1950's.
This means that although mercury is obviously the catalyst that results in susceptible babies getting Pink Disease, something must be causing the susceptibility to Pink Disease. This brings me to the 1950 hypothesis of Dr. Donald C. Cheek and Dr. C. Stanton Hicks.
The early theory of Cheek & Hicks
The research by Cheek and Hicks was based mainly on clinical and laboratory observations from hospitalised babies and from reports from other doctors. No general survey was done at the time, so their research was somewhat limited.
They looked for a cause based on the physiology of babies - in particular in relation to the immaturity of their adrenal glands. They noted that Pink Disease babies lacked salt and the administration of salt in baby formula later became a common means of treating that particular symptom.
About the Adrenal Glands
The adrenal glands (also known as the suprarenal glands) are small glands that sit on the top of each of the kidneys. The glands have an outer wall called the cortex and an inner portion called the medulla. The adrenal glands act on "instructions" from the pituitary gland and that gland in turn gets its "instructions" from the hypothalamus.
The adrenal cortex secretes numerous steroid hormones that regulate carbohydrate, protein and fat metabolism, and adjust the level of sodium excreted by the body thereby maintaining blood volume and blood pressure by keeping the water/sodium balance at the correct level. The steroid hormones also counteract inflammation and allergies and influence the secondary sex characteristics to a limited degree.
The adrenal medulla makes the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline). These hormones do the following:
- Epinephrine is secreted in response to low levels of blood sugar as well as exercise and stress. It increases the heart rate and blood flow to the muscles and brain, and causes relaxation of smooth muscles. It also assists in the breakdown of the storage product glycogen to glucose thereby increasing blood sugar levels, facilitates the release of fatty acids from fat tissue and causes the pupils of the eyes to dilate; and
- Norepinephrine narrows the blood vessels and raises blood pressure.
Obviously, if there is a disturbance to the function of the adrenal glands, hormones required by the body may not be secreted or may be secreted in insufficient amounts for the body to function properly.
Summary of Cheek’s and Hicks’ 1950 Theory
Cheek's & Hicks' theories, combined with the mercury theory of Warkany and Hubbard, may give the complete story of Pink Disease or at least, point us in the direction of the true cause and physiology of the disease. Research into the disease came to a halt when the disease virtually disappeared in the late 1950's.
Much of the following information comes from the 1950 research article by Cheek and Hicks and indicates the physiological causes they were investigating at that time.
Clinical tests on children with Pink Disease revealed a low plasma sodium content, a cell volume around 30% above normal, haemoglobin about 36% above average, a high plasma protein content, a high non-fasting blood sugar level, higher than average blood pressure plus a high pulse rate.
Cheek and Hicks hypothesised that Pink Disease sufferers had a problem with their adrenal glands, or with the glands adaptation to the after birth environment, because the function of the adrenal glands change markedly from the moment a baby is born.
Before birth, the baby lives in the reasonably constant internal environment of the womb with its needs being supplied via its mother. As soon the baby is born, its environment changes instantly. It starts to breathe. It is exposed to temperature, fluid and food variations.
At birth, the baby's adrenal glands are extremely immature. The glands now have to adapt to a new and fluctuating environment. The innermost part of the adrenal cortex involutes (curls inwards), and this involution extends to the outer cortical cells during the second month of life. Changes to the adrenal cortex continue during the first years of life. The cortical cells are replaced by a capsule of connective tissue that starts to disappear at two years of age as it is replaced by pheochrome tissue which eventually comes into contact with the cortical tissue. This stage of development continues until about 8 years of age.
The adrenal medulla is poorly developed at birth and continues to increase in size until adolescence.
Pink Disease generally occurs during the first 8 years of life. This is the period that corresponds to major post-foetal development of the adrenal glands.
Cheek and Hicks hypothesised that Pink Disease was a disease caused by the mal-adaptation (or delayed adaptation) of the adrenal glands to the variable conditions of the external environment after birth. They looked at the symptoms of Pink Disease in terms of adrenal insufficiency.
Because the adrenal glands regulate carbohydrate, protein and fat metabolism, as well as salt and water balance within the body, the body is adversely affected if they aren't working the way they should.
For babies with Pink Disease, there is excess sodium chloride lost from the fluid outside the cells leading to an imbalance between the contents inside the cells and outside the cells, resulting in water moving into the cells to correct the imbalance. This causes the cells to swell up and the blood becomes more concentrated and its volume is reduced as water from the blood has moved into the cells to compensate for the imbalance between the internal and external environment of the cell.
Since there is less blood volume, the blood is thicker, blood pressure increases, and the blood doesn't circulate around the body as well. This leads to poor circulation, particularly in the extremities (hence the pinkish and/or bluish colour of the hands and feet). Basically, all the tissues of the body have a reduced oxygen supply because of the poor circulation. This reduced oxygen supply has negative affects on all parts of the body including the skin and eyes.
As more water has moved into the cells, the parts of the body outside the cells become dehydrated. Thirst occurs and the water is replaced but this in turn increases the imbalance of salt and water in the body BECAUSE water alone is replaced - salt isn't replaced. This results in more water moving from outside the cells into the cells. The cells swell up even more and there is more dehydration outside the cells, more water intake, more salt loss, more water imbalance - the problem becomes self-perpetuating as the inadequately functioning adrenal glands try to balance the water inside and outside the cells. Those who did science at school may be familiar with osmosis - that is, the flow of fluid/chemicals/gases across semi-permeable membranes (such as cell membranes) from areas of higher concentration to areas of lower concentration to get into balance.
To treat Pink Disease, Cheek and Hicks concentrated on treating the symptoms of the disease - in particular, the loss of salt. One to two teaspoonfuls of salt were given per day to counteract all the symptoms that began with the loss of salt. In severe cases, desoxycorticosterone acetate was administered.
Dysfunctional adrenals also cause poor carbohydrate metabolism which results in poor muscular metabolism and muscle tone which in turn causes the apathy and listlessness of Pink Disease babies. Protein is also metabolised inefficiently as a result of the poorly functioning adrenal glands. Insufficient protein impairs muscular function, tone and strength, and blood sugar stability even further.
Basically, insufficient adrenal activity causes the symptoms of Pink Disease directly or indirectly.
Research carried out by Cheek's with others revealed that not all cases of Pink Disease responded as well or as permanently to the treatment regime mentioned above. It does, however, seem a reasonable hypothesis that the delayed or defective development of the adrenal glands may have been what caused 1 in 500 babies exposed to mercury to develop Pink Disease. The defective or delayed development could simply have resulted in Pink Disease babies being unable to cope with amounts of mercury within the normal range - that is, amounts of mercury that did not cause PD in 99.8% of babies.
As mentioned earlier, the adrenal glands are instructed by the pituitary gland and that in turn is instructed by the hypothalamus. The fault could, of course, lie in the pituitary or the hypothalamus.
The hypothalamus is the master gland responsible for keeping the body in homeostasis - that is, keeping the body's temperature, fluid, chemical, metabolic, blood pressure and hormone levels at the proper level.
It does this by "collecting" information on all aspects of the body, and if "adjustment" is required, it "instructs" the pituitary to instruct the other endocrine glands, including the adrenal glands, to do what is required to return the body to its correct homeostatic state.
It is obvious that any malfunction of the hypothalamus or the pituitary will have far-reaching and adverse effects.
Initially, Cheek’s theory was in opposition to the mercury theory, but Cheek and others continued their research throughout the 1950’s. That additional research led to Cheek’s later theory that mercury ingestion plus exposure to stress (heat, cold, illness, etc.) and a predisposition to Pink Disease were the factors that caused Pink Disease. The predisposition to Pink Disease could be genetic and might be explained by some type of problem involving biological enzymes and/or the substrates upon which the enzymes act. It was later shown that the enzyme that converted the adrenal hormone, epinephrine, into metanphrine in the body was blocked if mercury was present.
POST PINK DISEASE SYMPTOMS
Cheek recognized that long after a child had recovered from Pink Disease, symptoms could continue and the child could remain a nervous child and be irritable, have insomnia, be lethargic and sometimes bronchiectasis and urinary tract infections might occur.
The following information is based on the results of the Pink Disease Survey. The Survey compared 157 people who had Pink Disease with an age/gender matched control group.
The long term side-effects of Pink Disease are many and varied and there are probably three main reasons why those who had Pink Disease have the problems they do:
1. Permanent damage due to mercury exposure as a baby or even within the womb.
2. Developmental shortcomings due to being so ill for so long during the most important developmental stage of the human life cycle.
3. Ongoing mercury sensitivity or toxicity.
The Survey results shows that we have 2 or 3 times the incidence of a large range of health shortcomings as compared to the control group and that we suffer from these ailments more of the time and more severely.
Generally, people who had Pink Disease (PD) have worse health than other people of the same age and gender. Comparative data was obtained regarding the health or otherwise of peoples' eyes, mouth and throat, blood, muscles and bones, co-ordination, allergies and chemical sensitivities, general health, skin, heart and lungs, stress level and emotional well being, and gender related matters.
Those who had Pink Disease have more problems, and of the common/everyday problems, they have them more frequently.
Severe sensitivity to light is a symptom of PD and mercury poisoning. Most people who had PD not only still have severe light sensitivity, many of them have it most or all of the time.
Fifty percent of people who had PD also report night blindness and 66% reported spots/flashes of light before their eyes and aching sockets. This is twice as many as for the control group.
About the same percentage of the PD group and the control group wear glasses, although those who had PD started wearing glasses slightly earlier than average.
Mouth and Throat
Pink Disease and Mercury Poisoning cause jaw, throat and mouth problems, including loss of teeth. PD sufferers have 2 to 3 times the rate of many mouth and throat problems compared to the Control Group.
The most common PD problems include trouble swallowing, unexplained coughing fits, persistent cough, metallic taste in the mouth and feeling as if something is caught in the throat. The instance is about two-thirds for PD sufferers and about 20-30% for the control group. Swelling of the parotid and submaxillary glands is also common.
The questions on dental problems weren't as detailed as needed but early loss of teeth; excessive cavities in the teeth and use of dentures are more prevalent in the PD Group.
Both Pink Disease and Mercury Poisoning cause severe anaemia. Those who had PD, have a 30% higher incidence of iron deficiency and B12 anaemia and 3 times the amount of frequent bouts of anaemia, unexplained low haemoglobin counts and unexplained unusual results from blood tests.
Muscles and Bones
PD and mercury poisoning cause arthritic type problems and severe loss of muscle tone and muscle weakness. Most people who had PD are now in the age group where aches and pains are common, but they have 2 to 3 times the incidence of many of these problems than the control group do.
About two thirds have poly-myalgia and loss of strength in the arms. More than 50% have poor muscle tone in general, and one third have hips that "click" and painful cartilage connecting the ribs and sternum. Ninety percent have some arthritic like symptoms and the rate of osteoporosis is higher than that of the control group.
PD and mercury poisoning cause a type of minimal brain dysfunction that can cause co-ordination problems. Although the PD group is getting older, and co-ordination problems are more common in older age groups, PD sufferers are less co-ordinated and a lot clumsier than the control group members.
The incidence of co-ordination problems is 2 to 4 times higher for those who had Pink Disease. Two-thirds drift or stumble when walking, have a poor sense of distance and direction, are rather clumsy and jumble their words when speaking or writing.
Allergies and Chemical Sensitivities
PD and mercury poisoning affect the immune system badly. Allergies are a defective immune system response to common and everyday items. PD sufferers are much more allergic than members of the control group.
The incidence of allergies is 2 to 3 times higher for the PD group with allergies to foods, medicines, cosmetics and chemicals being the most common. A third or more of PD sufferers had problems with one of more of these items whereas the control group had an incidence of 10 to 25%.
Miscellaneous Health Problems
This part of the survey covered general health items and things that peculiarly relate to Pink Disease and mercury poisoning. On all items, PD sufferers have more problems/symptoms than the control group. They have more migraines and headaches, more fatigue, more cancer, more kidney, liver and bladder problems and slightly more auto-immune disorders.
Pink Disease affects the hands and feet. More than 50% of the PD Group now have problems with their hands and/or feet. These problems range from Raynaud's Syndrome, poor circulation, numb toes and tingling feet and misshapen fingers and nails. The incidence of hand and/or feet problems is twice the incidence of the control group and more than one third of the PD Group have misshapen fingers or nails compared to less than 8% of the control group. Those who had PD are also much more likely to have severe pain from bumping into things - a pain level far in excess of that expected.
The overall figures for auto-immune disorders seem to be higher than that shown on the survey. One batch of 500 collated surveys showed 1% had been diagnosed with multiple sclerosis (MS) and another 2% had been tested for it. The fact that more than 50% of people who had PD have numbness in parts of the body some of the time (or in 19% of cases, a lot of the time), probably explains why a much higher than expected percentage of the PD group have MS or have been tested for MS. It is estimated that only 1 in 1760 people have this disorder.
A Lupus like syndrome, without actually having lupus, is not uncommon among those who had PD. They have "allergy-like" reactions to sunlight, chronic fatigue, intermittent problems with their kidneys and other organs, arthritis and general poor health.
People who had PD seem to have much more trouble adapting to different temperatures, many being sensitive to both heat and cold. Most sweat excessively.
Generally, people who had PD have a poorer quality of physical health than those who didn't have it.
This section of the survey was done in early 2001 and does not have a control group. The participants were 92 people who had Pink Disease. At the moment, I have no comparative data to show whether the incidence of digestive and bowel difficulties is higher than that of other people of a similar age and gender.
The most noticeable symptoms of PD are raw red rashes and swollen and pink hands, feet and nose (hence the name Pink Disease). PD sufferers’ skin is worse than the skin of the control group.
They have 2 or 3 times the incidence of rashes and skin problems, their skin is drier and is more prone to sun related skin problems such as sunburn, solar urticaria and polymorphous light eruptions (burning red spots a bit like hives).
More than half the PD Group has skin problems of some type. Dry scaly skin, psoriasis, being prone to rashes, and getting rashes or red spots from sun exposure are the most common problems. Sixty percent sunburn easily compared to 40% of the control group.
Unusually fair skin, which is not inherited, affects 1 in 8 PD sufferers compared to just 1 in 40 of the control group. Sixteen percent of PD folk have also had wrinkly hands all their lives (although most, I dare say, now have wrinkly hands as the members of the PD group are all middle-aged and older). There is a connection between wrinkly hands and severe B12 deficiency anaemia. This type of anaemia was once thought to be a cause and/or symptom of Pink Disease. The fact that a much higher than expected amount of the PD Group had wrinkly hands when they were children is some evidence that that type of anaemia was involved at least as a symptom.
Lungs & Circulation
Mercury affects the lungs badly, and this is why many PD babies died - they caught severe bronchopneumonia and other lung infections. The result of the damage is more asthma, bronchiectasis, breathlessness, poor circulation and slightly more heart disease.
One third of the PD Group has asthma and more than 75% suffer breathlessness from minor exertion. Thirty percent have bronchiectasis compared to 5% of the control group. Mercury is extremely toxic to the lungs and can cause tightness, incomplete expansion, and collapse of the lungs, emphysema and pneumonia. Broncho-pneumonia was one of the major causes of death in babies with Pink Disease. Mercury also damages cilia. Cilia are tiny hairlike structures that move mucus via a waving motion. If the cilia are damaged and can’t move mucus effectively, then mucus builds up in the lungs. The bronchi of the lungs, reproductive tract and nasal cavities all have cilia in them. Young’s Syndrome, which is a type of male infertility, occurs almost exclusively in men who have a history of Pink Disease or other mercury exposure.
More than a quarter have chest pains and over half have tachycardia. Seventy-five percent have pins and needles in some part of the body (30% have this problem often or always). More of the PD Group has been diagnosed with mitral value problems and heart murmurs.
Stress Level, Emotional Wellbeing and Personality
Mercury poisoning and therefore PD causes emotional difficulties such as shyness, confusion and a sense of alienation. The emotional turmoil of PD babies has stayed with them. Although the survey results don't indicate a higher rate of serious psychiatric disorders, they do reveal more shyness, alienation, depression, nervousness and sensitivity than is suffered by the control group. These indicate a poor state of emotional well-being, a lot of which may simply be caused by their poorer state of physical health, but some of which is typically "mercury poisoning" related.
Depression, insomnia, nightmares, feelings of helplessness, forgetfulness, lack of self-confidence, nervousness, poor concentration, social phobia, shyness, anxiety, and sensitivity to noise are all very common some of the time in both the PD group and the Control Group. These things are, however, more common in the PD group and the incidence of them is more frequent. For example, 40% of the PD group have insomnia often or always compared to 20% of the Control Group and 35% often or always lack self-confidence compared to 10% of the Control Group. 29% of the PD group are often/always shy while just 7% of the Control Group are.
The most common diagnosed mental illness was clinical depression and twice as many of the PD Group have been diagnosed with this compared to the control group. More of the PD Group admitted to having Bipolar Disorder as well.
It's uncertain how accurate the answers to the mental illness questions are. Everyone who did the survey is middle-aged or older - that is, they were all brought up in the era when mental illness was a stigma. In other words, people may have been "shy" about answering "yes" to those questions.
Gender Specific Problems
Mercury can cause infertility or result in a reduction in fertility. It can do this because mercury damages the cilia, as mentioned above. Cilia cause movement of sperm along the male epididymal duct or ova along the Fallopian tubes.