# Health risk assessment of exposure to Polycyclic Aromatic Hydrocarbons in bread from Iranian markets: Application of monte carlo simulation approach

**Authors:** Najmeh Khodadadi, Masoumeh Saghi, Sina Mashayekhi, Negin Bashirian, Fateme Asadi Touranlou, Seyedeh Belin Tavakoly Sany

PMC · DOI: 10.1371/journal.pone.0341584 · PLOS One · 2026-02-23

## TL;DR

This study assesses health risks from PAHs in Iranian bread, finding higher contamination in traditional baking and suggesting ways to reduce exposure.

## Contribution

The study applies Monte Carlo simulation to evaluate PAH-related health risks in bread from Iranian markets, comparing traditional and industrial baking methods.

## Key findings

- Traditional breads had significantly higher PAH levels than industrial breads.
- Probabilistic assessment showed acceptable to low carcinogenic risk, with BaP as the main contributor.
- PAH levels in Iranian breads are generally acceptable but require continued monitoring and regulation.

## Abstract

Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental contaminants formed during high-temperature processing of food and are associated with both carcinogenic and non-carcinogenic health effects.

A total of 96 bread samples (Lavash, Sangak, and Barbari) were collected from industrial and traditional bakeries across eight municipal zones of Mashhad, Iran. Sixteen priority PAHs were quantified by GC-MS after microwave-assisted saponification and DLLME clean-up. Toxic equivalent concentrations (BaPeq), daily dietary exposure, incremental lifetime cancer risk (ILCR), and Monte Carlo probabilistic modelling (100,000 iterations) were used for risk characterisation.

Mean Σ₁₆PAHs were significantly higher in traditional breads (68.63 ± 4.57 µg/kg) than industrial breads (39.87 ± 3.68 µg/kg; p < 0.001), with Lavash showing the highest levels (66.58 ± 6.02 µg/kg) and Sangak the lowest (40.95 ± 1.63 µg/kg). Naphthalene dominated light PAHs; fluoranthene and pyrene were predominant heavy PAHs. Mean BaP concentrations (0.05–0.10 µg/kg) were below the EU limit of 1 µg/kg. Mean TEQ was 0.18 µg/kg, with BaP contributing ~58%. Probabilistic assessment showed acceptable to low carcinogenic risk, slightly higher for traditional baking. Sensitivity analysis identified BaP as the primary driver. Compared globally, PAH levels in these Iranian breads indicate an acceptable risk, though continued monitoring and regulation are needed.

Current PAH exposure via bread in Mashhad is generally acceptable, but traditional baking markedly increases contamination. Transition to indirect-heating ovens, improved ventilation, and regular monitoring are recommended to minimise exposure.

## Linked entities

- **Chemicals:** Naphthalene (PubChem CID 931), Fluoranthene (PubChem CID 9154), Pyrene (PubChem CID 31423), BaP (PubChem CID 2336)

## Full-text entities

- **Diseases:** diabetes (MESH:D003920), Cancer (MESH:D009369), diseases (MESH:D004194), oral cancer (MESH:D009062), learning disabilities (MESH:D007859), Toxic Substances (MESH:D065606), toxicity (MESH:D064420), skin, lung, pancreatic, esophageal, bladder, colon, and breast cancer (MESH:C537262), Carcinogenic (MESH:D011230), infectious diseases (MESH:D003141)
- **Chemicals:** dichloromethane (MESH:D008752), FLR (MESH:C041509), FLT (MESH:C007738), indeno[1,2,3-cd]pyrene (MESH:C041508), B[a]P (MESH:D001564), methanol (MESH:D000432), B[b]F (MESH:C006703), Benz[a]anthracene (MESH:C030935), sodium chloride (MESH:D012965), metal (MESH:D008670), PYR (MESH:C030984), Zinc acetate (MESH:D019345), oxygen (MESH:D010100), acetic acid (MESH:D019342), CHR (MESH:C031180), HCl (MESH:D006851), Biphenyl (MESH:C010574), NAP (MESH:C031721), PAH (MESH:D011084), ethanol (MESH:D000431), water (MESH:D014867), tetrachloroethylene (MESH:D013750), acetone (MESH:D000096), carbohydrates (MESH:D002241), oil (MESH:D009821), ACE (MESH:C042552), HPAHs (MESH:C060424), starch (MESH:D013213), Helium (MESH:D006371), BaPeq (-), charcoal (MESH:D002606), hydrogen (MESH:D006859), PHE (MESH:C031181), ACY (MESH:C042553), dibenz[a,h]anthracene (MESH:C026486), potassium hydroxide (MESH:C029943), lipids (MESH:D008055), ANT (MESH:C034020)
- **Species:** Meleagris gallopavo (common turkey, species) [taxon 9103], Nicotiana tabacum (American tobacco, species) [taxon 4097], Homo sapiens (human, species) [taxon 9606], Oryza sativa (Asian cultivated rice, species) [taxon 4530]

## Full text

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## Figures

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## References

47 references — full list in the complete paper: https://tomesphere.com/paper/PMC12928422/full.md

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Source: https://tomesphere.com/paper/PMC12928422