Arsenic Poisoning: Symptoms, Types, Causes and Treatment

Arsenic poisoning, also known as arsenicosis, is a global public health issue that affects millions of people every year. Whether through contaminated water, food, or industrial exposure, arsenic can enter the body and cause a wide array of acute and chronic health problems. Understanding the symptoms, types, causes, and modern approaches to treatment is crucial for prevention and effective management. This article provides an in-depth, evidence-based overview of arsenic poisoning, using the latest scientific research to guide readers through its complexities.

Symptoms of Arsenic Poisoning

Arsenic poisoning presents with a variety of symptoms that can range from subtle and non-specific to severe and life-threatening. Recognizing these signs early is vital for prompt intervention and minimizing long-term health effects.

System	Common Symptoms	Severity/Duration	Source
Skin	Hyperpigmentation, Hyperkeratosis, Mee's lines, Skin cancer	Chronic	1, 3, 4, 6, 9
Gastro	Nausea, Vomiting, Abdominal pain, Diarrhea	Acute/Chronic	2, 4, 5, 6
Nerve	Peripheral neuropathy, Encephalopathy, Delirium	Subacute/Chronic	2, 4, 5, 6
Blood	Anemia, Leucopenia, Bone marrow depression	Subacute/Chronic	4, 5, 6
Liver	Elevated liver enzymes, Portal hypertension	Chronic	4, 9

Table 1: Key Symptoms

Skin Manifestations

One of the most recognizable features of chronic arsenic poisoning is its effect on the skin. Hyperpigmentation (darkening of the skin) and hyperkeratosis (thickening, especially on the palms and soles) are hallmark features. Mee's lines—transverse white lines on the fingernails—may also appear. Over time, chronic exposure significantly increases the risk of skin cancers, including squamous cell carcinoma and basal cell carcinoma 1, 3, 4, 6, 9.

Gastrointestinal Symptoms

Acute arsenic poisoning is often marked by sudden and severe gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and profuse diarrhea. These symptoms may develop within hours of exposure and, if left untreated, can progress to dehydration and shock 2, 4, 5, 6.

Neurological Involvement

Peripheral neuropathy (tingling, numbness, or weakness in the limbs) is a common consequence of both subacute and chronic arsenic exposure. In more severe cases, encephalopathy or delirium may manifest, particularly in situations of high-dose or prolonged exposure 2, 4, 5, 6.

Hematologic and Hepatic Effects

Arsenic can damage the blood-forming system, leading to anemia, leucopenia (low white blood cells), and bone marrow depression. Liver dysfunction is also seen in chronic poisoning, with elevated enzymes and, in extreme cases, non-cirrhotic portal hypertension and splenomegaly 4, 5, 6, 9.

Other Symptoms

Nonspecific symptoms such as fatigue, malaise, and a metallic taste are common but can be easily misattributed to other illnesses, making diagnosis challenging 3, 4. Long-term exposure is also linked to cardiovascular disease, diabetes, hypertension, and kidney damage 7, 13.

Types of Arsenic Poisoning

Arsenic poisoning can be classified based on the duration and intensity of exposure, leading to distinct clinical presentations.

Type	Exposure Duration	Primary Effects	Source
Acute	Hours to days	GI symptoms, shock, encephalopathy	2, 4, 5
Subacute	Days to weeks	Mixed GI/Neurologic, anemia	5
Chronic	Months to years	Skin lesions, cancer, neuropathy	1, 3, 4, 6, 9

Table 2: Types of Arsenic Poisoning

Acute Arsenic Poisoning

This form occurs after a large, often intentional or accidental ingestion or inhalation of arsenic. Symptoms appear rapidly and include severe gastrointestinal upset, cardiovascular instability, encephalopathy, and multi-organ failure. If not treated quickly, acute poisoning can be fatal 2, 4, 5.

Subacute Arsenic Poisoning

Subacute poisoning involves repeated exposure over days or weeks. It bridges the gap between acute and chronic forms, with persistent gastrointestinal symptoms, early signs of peripheral neuropathy, and evidence of hepatic and hematological disturbances. In one industrial accident, workers developed both GI symptoms and later peripheral nerve damage within a few weeks 5.

Chronic Arsenic Poisoning

Chronic exposure, the most prevalent form worldwide, results from ingestion of small amounts of arsenic over months or years—commonly through contaminated water or food. The effects are insidious, involving multiple organ systems. Skin changes, peripheral neuropathy, chronic liver disease, and a markedly increased risk of cancer dominate the clinical picture 1, 3, 4, 6, 9.

Causes of Arsenic Poisoning

Understanding the diverse causes of arsenic poisoning is essential for risk assessment, prevention, and policy-making.

Source	Exposure Route	Notable Examples	Source
Groundwater	Ingestion	Bangladesh, India, Mexico, Taiwan	1, 3, 4, 7, 10, 14
Food (crops, seafood)	Ingestion	Rice, vegetables, fish	10, 14
Industrial	Inhalation, Ingestion	Mining, smelting, pesticide use	2, 5, 9, 14
Medicinal/Herbal	Ingestion	Anti-asthmatic herbal remedies	2, 6
Pesticides	Ingestion	Contaminated well water	9

Table 3: Causes of Arsenic Poisoning

Natural Sources

Arsenic is a naturally occurring metalloid found in soil and rocks. Groundwater contamination is the leading cause of arsenic poisoning worldwide, affecting millions in regions such as Bangladesh, India, Mexico, and parts of Southeast Asia and South America. The risk is highest where groundwater is the main source of drinking water 1, 3, 4, 7, 10, 14.

Food Contamination

Arsenic can accumulate in crops irrigated with contaminated water, especially rice, vegetables, and seafood. Chronic low-level exposure through diet is a growing concern, particularly in Asia where rice is a staple food 10, 14.

Industrial and Occupational Exposures

Mining, smelting, and the use of arsenic-containing pesticides or wood preservatives are significant sources. Workers may be exposed through inhalation or direct ingestion, and improper disposal can contaminate local water supplies 2, 5, 9, 14.

Medicinal and Herbal Products

Traditional remedies and herbal medications can contain dangerously high levels of arsenic. Notably, anti-asthmatic preparations in some countries have led to widespread chronic poisoning 2, 6.

Pesticides and Environmental Pollution

Past use of arsenic-based pesticides has led to persistent contamination of drinking water sources, as seen in documented household clusters of arsenicosis 9. Environmental buildup poses risks long after the initial contamination.

Treatment of Arsenic Poisoning

While prevention is paramount, a range of treatment strategies exist for managing arsenic poisoning, with varying effectiveness depending on the type and duration of exposure.

Treatment Approach	Main Strategies	Limitations/Notes	Source
Immediate Decontamination	Stop exposure, GI lavage	Supportive for acute cases	2, 4
Chelation Therapy	BAL, DMSA, DMPS, MiADMSA	Efficacy, side effects, limitations	4, 11, 12, 13
Antioxidants	Vitamin C, E, others	Adjunctive, experimental	8, 13
Symptomatic Treatment	Hydration, electrolyte correction	Essential supportive care	2, 4
Prevention	Remove arsenic sources, safe water	Most effective long-term strategy	2, 8, 10, 14

Table 4: Treatment Modalities

Immediate Measures

For acute poisoning, the first step is to halt exposure and initiate decontamination. This may involve gastric lavage if ingestion is recent, intravenous fluids to manage dehydration, and correction of electrolyte imbalances 2, 4.

Chelation Therapy

Chelators are agents that bind heavy metals, enhancing their excretion. The following are commonly used:

• Dimercaprol (BAL): Historically the mainstay for acute poisoning, but has notable side effects 4, 12, 13.
• Dimercaptosuccinic acid (DMSA): Effective and less toxic, used for both acute and some chronic cases, though limited in removing intracellular arsenic 4, 11, 12, 13.
• Dimercaptopropanesulfonic acid (DMPS): Similar to DMSA, with its own set of limitations 4, 11, 12, 13.
• Monoisoamyl DMSA (MiADMSA): Emerging as a promising chelator, especially for chronic exposure due to better intracellular penetration and efficacy in animal studies 11.

Chelation is most effective in acute or subacute poisoning. In chronic poisoning, benefits are less clear, and chelators may not reverse established organ damage 4, 12, 13.

Antioxidant Therapy

Arsenic induces oxidative stress, so antioxidants like vitamin C and E are being studied as adjunctive therapies. Combining antioxidants with chelation may improve outcomes, though robust clinical evidence is still limited 8, 13.

Supportive and Symptomatic Care

Management of dehydration, correction of electrolyte imbalances, and treatment of complications (e.g., neuropathy, anemia) are essential components of care 2, 4.

Prevention and Long-Term Management

The cornerstone of arsenic poisoning control is prevention. This means:

• Identifying and removing arsenic sources (e.g., switching to safe water supplies)
• Regular surveillance in at-risk populations
• Remediation technologies for water and soil
• Public education and policy interventions 2, 8, 10, 14

There is currently no universally effective treatment for chronic arsenic poisoning; focus remains on minimizing further exposure and managing symptoms 2, 3, 7, 13.

Conclusion

Arsenic poisoning remains a significant global health challenge due to its widespread environmental presence and the subtlety of its symptoms. Understanding the spectrum of clinical features, sources, and available management options is critical for both healthcare providers and the public.

Key Takeaways:

• Symptoms: Range from acute GI upset to chronic skin, nerve, liver, and hematological issues; skin changes are a hallmark of chronic exposure 1, 3, 4, 6, 9.
• Types: Divided into acute, subacute, and chronic forms, each with distinct clinical patterns 2, 4, 5.
• Causes: Predominantly environmental (groundwater, food), but also industrial and medicinal sources contribute 1, 2, 3, 6, 7, 9, 10, 14.
• Treatment: Relies on exposure cessation, supportive care, chelation therapy (with varying efficacy), antioxidants, and—most importantly—prevention and safe water initiatives 2, 4, 8, 11, 12, 13, 14.

By raising awareness and promoting evidence-based interventions, the burden of arsenic poisoning can be reduced, safeguarding the health of populations at risk.