Heat and Dust: why lead poisoning is called the “Summer Disease”

The following was originally published in LEAD Action News vol 4 no 1, Summer 1996:

Ref: (1979) V Garnys, R Freeman and L Smythe "Lead Burden of Sydney Schoolchildren", Uni of NSW, p160.

Several publications [AM Baetjer (1959) Industrial Medicine and Surgery, 28, 137, and JC Aub et al (1925) Mediano, 4, 1] have noted the increased incidence of childhood lead poisoning during the summer months. In a recent publication entitled "The summer disease: An integrative model of the seasonality aspects of childhood lead poisoning", JM Hunter (1977) [in "Social Science and Medicine" 11, 691-703] reviewed this phenomenon by considering air pollution, maternal-foetal exchange of lead, biological models and the effects of sunlight in the USA.

In Australia, Freeman [various references 1969-1973] noted the increased number of hospital admissions in summer for childhood lead poisoning.
[Ref: www.lead.org.au/lanv4n1/lanv4n1-5.html ]
In his 1970 article “Chronic Lead Poisoning in Children: A Review of 90 Children Diagnosed in Sydney, 1948-1967 1. Epidemiological Aspects”, Freeman observed:

Seasonal Incidence

“Most of the children, and in particular those with acute encephalopathy, presented in the hot summer months, December to February, but cases occurred throughout the year, often precipitated by an intercurrent infection. Children with moderately severe poisoning may seem well during the winter months, but tend to develop symptoms during the hot summer period. The reason for this is not clear. Solar radiation, which increases the synthesis of vitamin D in the skin, may aid absorption of lead, and factors causing dehydration or acidosis, which like infections mobilize lead from the bones, may be more common in the hot weather.”

JM Hunter also wrote “The summer disease. Some field evidence on seasonality in childhood lead poisoning” published in "Social Science and Medicine" in 1978 Jun;12(2D):85-94.

It is certainly worth investigating if average blood lead levels are rising in other communities where average temperatures are rising. Communities hosting lead product manufacturing, lead acid battery recycling, lead mining or smelting operations are the most likely to have biannual blood lead survey data over several decades, which could then be compared to temperatures over the same period.

Do high blood lead levels cause a rise in body temperature?

It appears that high blood lead levels do in fact cause a rise in body temperature. Hunter (1975) cites the following examples in “The Diseases of Occupations” section on Lead Poisoning:

“In 1947 Bini and Bollea described two fatal cases of poisoning, where ethyl-petrol intended for use as aviation fuel was used for the dry cleaning for clothes. The patients were Italians, a man of American airmen stationed in Italy. They worked in a room which was small, closed and poorly ventilated, and they ironed the clothes while they were still wet with the leaded petrol. After a few days’ exposure they suffered from anorexia, vertigo, general weakness and insomnia. About a week later there was psychomotor agitation, with a rapid stream of disconnected talking and mental confusion in the nature of a toxic confusional delirium with visual and auditory hallucinations occurring together, tremors affecting all muscles, myoclonus and choreiform movements. Two days later they became comatose and died with a temperature of 105 degrees F.”

In 1970, Ronald Freeman reported that 11 of the worst cases in his research paper entitled: “Chronic Lead Poisoning in Children: A Review of 90 Children Diagnosed in Sydney, 1948-1967 2. Clinical Features and Investigations” had presented at the hospital with infection (presumably including fever):

“More than half the [90] children had evidence of encephalopathy [such as convulsions, coma or signs of raised intracranial pressure] and in most of them it was present at the time of their admission to hospital; but in a few cases it appeared during the subsequent course of the illness, when it was nearly always precipitated by an acute infection.

How does heat affect the lead poisoned individual?

The following was originally published under the title “Lead Workers Case Studies” in LEAD Action News vol 4 no 1, summer 1996:

Case G is a firearms instructor for the Security industry. When he had his blood lead tested and found he had a blood lead level of 1.68 µmol/L (35 µg/dL) his doctor "was helpful, but I don’t think she knows that much about it herself". The senior police sergeant in charge of the Firearms Registry in his area had suggested that he be tested when the instructor started getting "very short-tempered". The Firearms Registry supervises all security firearms instructors in Victoria. The senior sergeant had been lead-poisoned himself (4.1 µmol/L - over 80 µg/dL) and needed chelation, and so was aware of the symptoms. The instructor had previously worked only on outdoor ranges. The day after running his first 3 hour course at an indoor range, he felt "generally off-colour. The range isn’t well-ventilated". After 12 of these sessions, "I have violent mood swings -my wife says it’s like bad PMT. I realise it at the time but I can’t stop myself. Any increase of pressure on me is hard to handle. When I go out into the sun, if I get a lot of UV, I know I’m going to get a lead dump. I get hot flushes - it feels like I’m spontaneously combusting from inside - my entire body heats up and breaks out into a sweat. [See article following "Lead Poisoning: the Summer Disease".] I have short term memory loss and I get a hot metallic taste in my mouth after work." He also suffers joint pain for which he is being treated with anti-inflammatories. [Ref: www.lead.org.au/lanv4n1/lanv4n1-4.html ]

And it’s not just humans who suffer worse lead poisoning effects when they get hot. One GLASS caller told us about her dog fitting when he was overheated:

“I had an old English sheep dog years ago in an old place in Sydney & my husband was stripping furniture and the dog chewed a door. I was playing with the dog and he went into fits. If he got slightly hot or excited he'd have the fits and I never knew when they'd happen and it really upset me at the time and the vet took ages to figure out that it was lead poisoning.” [Ref: GLASS Call ID 200703-620, 28th March 2007]

Four thousand nectar-eating birds died of lead poisoning in Esperance, Western Australia in December 2006 during a week in which “there was one day – 17th December – when the bird deaths were really bad” (according to the resident Michelle Crisp, who first alerted the authorities to them) and the temperature was 42.5 degrees C – the hottest day in December 2006 [Ref: www.bom.gov.au]. A further 180 birds died in the week ending 9th March 2007, again mostly on the 8th March when the temperature was 38.5 degrees, again the hottest day of that month [Ref: www.bom.gov.au]. The people of the town have been left wondering whether a single incident of lead ore dust escape from the port facilities preceded each round of deaths or whether the birds were slowly accumulating lead from ongoing dust escape and the temperature was what actually finished the lead poisoned birds off. Some people theorize that the overheated birds would have taken in more nectar or water, which if highly lead contaminated, may have been the pathway to death, but no particularly highly contaminated water in their range has yet been identified, although a dam in the area that had water in it in December was pumped dry before the water could be tested for lead [Ref: personal communication with Michelle Crisp. GLASS Call ID 200702-096, 7th February 2007]

Saunas or heating and showering as a method of “getting the lead out”

Knowing that heat moves lead out of the body via sweat, saunas followed by showering are a now well-established alternative treatment for lead poisoning. Here follows an example of one person’s experience with heat treatment:

“I was exposed to lead paint working as a remodeler on old Victorian houses. I had been stupid, thinking that plumbism was just for parents of small children to worry about. That was over a year ago. At the time, I was experiencing some alarming symptoms including trouble concentrating, sleep and appetite disruption and a very noticeable loss of my sex drive - these were the things that prompted me to get tested in the first place. Since then I would have to say that I'm better, but as you can probably imagine it's hard to say by how much. As far as treatment goes, I haven't done much except to take a lot of baths and saunas to try and flush my system. I also started doing "Bikram" yoga, which consists of yoga performed in a very hot room (115 degrees!). I don't know if all this has helped, but I figure it can't hurt.” [Ref: GLASS Call ID 200702-083, 5th February 2007]

The following quote is from a 70 year old lead poisoned woman, a member of The LEAD Group’s Lead Poisoned Adults e-group, 21/4/09:

“I have chelated for lead off and on for three years. When the levels go down, I tolerate heat. The first sign of lead levels rising, is the burning in my feet and ankles, the intolerance to heat and no endurance in any sport.”

Climate change, floods, cyclones and the potential for lead poisoning

An increase in flooding from severe cyclones is a predicted effect of global warming in some parts of the world. Flood water provides an opportunity for lead particles - the legacy, amongst other things, of years of leaded-petrol use - to be spread over a wider area. In the article “Characterization of Flood Sediments from Hurricanes Katrina and Rita and Potential Implications for Human Health and the Environment.” by Geoffrey S. Plumlee et al, the authors conclude that:

“Several lines of evidence indicate that flood sediments in the downtown New Orleans area were derived primarily by reworking of older, highly contaminated urban soils, with elevated concentrations of lead, arsenic, other heavy metals, and PAHs (e.g., benzo(a)pyrene). Lead and some other metal contaminants in the downtown soils and flood sediments are likely to be quite bioaccessible, and therefore the downtown soils and their derived sediments pose a potential long-term exposure risk to residents.” [Ref: http://pubs.usgs.gov/circ/1306/pdf/c1306_ch7_i.pdf ]

Climate change, wildfires and sources of lead released during fires

The DVD of the movie An Inconvenient Truth by Al Gore (2006) contains in the Special Features, a 2007 documentary entitled An Update with Former Vice President Al Gore in which Gore discusses trends which came to light since the making of the movie, such as the increased frequency and severity of wildfires caused by global warming. Wildfires are known by different names in other countries, eg forest fire, savannah fire, brush fire, vegetation fire, grass fire, peat fire, bushfire (in Australasia), and hill fire. As discussed above, plants take up lead from the soil so every wildfire will contribute some lead pollution but the issue becomes far more serious when lead-painted buildings and infrastructure start to burn, and worse still if leaded items such as vehicle and emergency power supply lead acid batteries, lead pipe organs or radiation shielding start to get turned into lead fumes. Of course, when people are burned in fires, their lifetime stores of lead are released. Depending on the area burned, fires can be a major source of lead air pollution and global warming is predicted to increase the length of the annual fire season.

Action on climate change prevents or abates a plethora of other environmental problems!

Drawing by Anne Roberts, 1997