Non-infectious environmental hazard examples: migrant health guide
Advice and guidance on the health needs of migrant patients for healthcare practitioners.
Lead poisoning in migrant children
The incidence of lead poisoning has dramatically declined in affluent countries following the ban on the use of lead based paint and leaded petrol. However, in many countries across the world there is ongoing lead exposure from the combustion of lead-containing fuel; industrial emissions; burning of fossil fuels and waste; and lead-containing traditional remedies, foods, ceramics, and utensils. There is no known safe level of lead exposure.
The highest blood lead levels (BLL) and burden of disease from lead exposure occur in the lowest income countries and an estimated 90% of children with elevated BLL live in low income regions.
Studies have indicated that birthplace and the areas where migrants have lived are more important predictors of elevated BLL than ethnicity. In the USA, a study of newly arrived refugee children under 7 years old between 1995 to 1999 found elevated BLL in:
- 7% from Northern Eurasian countries
- 25% from the Near East (predominately Iraq)
- 27% Africa
- 37% Asia (predominantly Vietnam)
- 40% from Central America or Caribbean countries
A review of BLL in migrant children newly arrived in Hong Kong from mainland China found that lead poisoning was common (18.1%) and was similar to the prevalence found in new migrants arriving from mainland China to the USA. The BLL in these children were lower on subsequent screening indicating environmental exposures in their country of origin as the most likely source of poisoning.
Arsenic poisoning in Bangladeshi population
In the UK, arsenic in drinking water should not exceed 10 μg per litre, at which level poisoning does not occur.
In Bangladesh, groundwater contaminated with arsenic has been used for drinking since the 1940s, and the number of people consuming contaminated water has increased significantly in the last 20 years. It is estimated that between 28 and 62% of the total population of Bangladesh are at-risk of consuming contaminated water.
Features of arsenic poisoning may appear immediately or develop slowly over time, months to years after exposure has occurred, and may therefore be seen in migrants from affected areas such as Bangladesh.
Heavy metal poisoning and Ayurvedic medicine
Ayurveda is a traditional Indian medicine used widely by children and adults across the Indian subcontinent and among South Asian communities settled throughout the world.
Some Ayurvedic remedies contain heavy metals such as lead, mercury and arsenic and there have been multiple reports of clinically significant heavy metal poisoning, particularly from lead, associated with their use.
Heavy metal poisoning and cosmetics
The use of Kohl and skin lightening creams is very prevalent amongst women from the Middle East, Asia and Africa, for both cosmetic and perceived medicinal purposes. These products are often imported from countries where there are less stringent standards and regulations for production and there are numerous cases of chronic poisonings attributed to such products.
Blood analysis of children in the UK who used Kohl found high BLL and relatively low haemoglobin levels.
Mercury is one of the active ingredients in skin lightening creams and there have been several case reports of renal disease due to mercury poisoning in individuals using these products.
Adverse drug interactions and traditional medicine
Herbal remedies in various traditional medicine systems may be taken alongside therapeutic drugs, raising the potential for drug-herb interaction. For example:
- Ginkgo biloba (used in many Chinese medicine formulas for a variety of indications) can cause bleeding when combined with warfarin or non-steroidal anti-inflammatory drugs, raise blood pressure when combined with a thiazide diuretic and coma when combined with tetracyclic antidepressants
- Karela (Momordica charantia), a fruit used in cooking across the Indian subcontinent, is also taken for its ability to lower blood sugar; it can interact with chlorpropamide and may produce hypoglycaemia in an otherwise stabilised diabetic patient
Chemical contamination of imported food products
Imported food products may be purchased in a variety of specialised outlets. On occasion, some products have been found to be chemically contaminated.
Sudan 1 was found in certain Indian food products available in Asian supermarkets across the country in 2009. Sudan 1 is a possible carcinogen and is not allowed to be added to food produced in the UK and EU.
In 2004, a survey of total and inorganic arsenic in 5 varieties of seaweed imported into the UK showed that one seaweed variety, hijiki, contained a significant level of inorganic arsenic. The predominant form of arsenic usually ingested via the diet is in organic form, however, inorganic arsenic is significantly more toxic. This seaweed is used in Japanese cooking and is available in specialist shops selling Asian and far eastern foods. The FSA issued warnings against consuming this food item in 2004 and 2010.
Heavy metal poisoning and geophagy
Geophagy or earth eating is a cross cultural phenomenon that is more common amongst women and children than men. Geophagy is evident in Iran, China, the Indian sub-continent, South East Asia and Africa, and the practice can result in serious health problems such as poisoning as a result of heavy metal exposure.
In the UK, there is evidence that some pregnant Asian women have consumed soil imported from South Asia. Analysis of samples from Bangladesh in the UK found that the soil consumption could be a significant source of arsenic, cadmium and lead which can have potential adverse health and developmental effects on the unborn baby.
Pregnant women in Nigeria and Cameroon consume a local clay known as ‘Calabar chalk’ or ‘Calabash clay’ and this practice persists in the UK with women able to purchase specially prepared blocks or pellets of the soil from ethnic shops and markets. Women believe that it is good for their unborn baby. However, in December 2009, the USA FDA issued a warning against the use of these products as high levels of lead and arsenic were detected in samples.
Lead poisoning in the home
Changes in the law have resulted in a reduction in the level of lead in the environment. However, in the UK, a small number of children remain exposed to harmful levels of lead, for example from old lead paint in the home.
In France, poor-quality housing is an important risk factor in frequent incidents of lead poisoning among children of migrants living in old and poorly maintained houses, and it is likely that similar issues exist amongst migrants in the UK.
In 2003, a case of lead poisoning in a 3 year old boy born in the UK to Sudanese parents was linked to the child peeling off and eating paint from the walls of their 1970’s built flat. The child developed behavioural changes and had a high BLL. The patient’s siblings also had elevated BLL and environmental sampling showed that paint on many interior surfaces contained significant amounts of lead.
Occupational exposure
Migrants form a large proportion of the workforce in low-skilled occupations and in parts of the horticultural and food processing industries the workforce is almost exclusively foreign born. Migrants are more likely to work in sectors or occupations where there are existing health and safety concerns. Notification and registration of work-related injuries and diseases in migrants are often incomplete or do not distinguish migrants. However, the available data show that unskilled migrant workers tend to have higher risks of work-related injury and long-term occupational health related illness.
In 2008, the Health and Safety Executive reported the case of lead poisoning amongst foreign construction workers while restoring a Scottish manor. The men were exposed to lead dust while sanding surfaces covered with lead based paint.
There is substantial evidence that pesticide-related illness is an important cause of acute morbidity among migrant farm workers across the USA. Exposure to organophosphates is associated with long-term illness in UK sheep farmers and it is likely that migrants working in this industry will also be adversely affected.
See the non-infectious environmental hazards main page of the guide for further information.