Ex-Cyclone Alfred is bringing significant rainfall to southeast Queensland and the Northern Rivers of New South Wales. Flooding has hit Lismore, Ballina, Grafton, Brisbane and Hervey Bay, which received 150 mm of rainfall in two hours this morning.

Tragically, a 61-year-old man died after being swept away in floodwaters near Dorrigo in northern New South Wales.

More heavy rain and flash flooding is expected in the coming days as the weather system moves inland and weakens.

Climate change is making these weather events more intense and frequent. Earlier this year, far north Queensland experienced major flooding. As residents of the Northern Rivers, this latest disaster is especially tough because only three years ago we faced the catastrophic 2022 floods.

We’ve studied the impact of floods on human health and wellbeing, and found floods are linked to a range of physical and mental health effects in both the short- and long-term.

So what might you experience if you live in an area affected by these floods?

We reviewed the evidence

We recently reviewed research on the physical and mental health impacts of floods across mainland Australia. We included 69 studies in our review, published over 70 years. The majority were from the past ten years, examining the effects of floods in Queensland and NSW.

These studies suggest people can expect a range of health impacts. Immediate physical health effects of floods include drowning, falls and injuries.

Chronic diseases such as diabetes or renal disease can also worsen due to factors such as reduced access to transport, health-care services, medications and hospitals.

Exposure to contaminated floodwaters can lead to skin infections, while respiratory problems can occur due to mould and damp housing in the aftermath of floods.

Floods also create ideal conditions for mosquito borne infections such as Ross River virus and Murray Valley encephalitis, while also spreading infectious diseases including leptospirosis, a bacterial infection from contaminated soil.

There are mental health consequences too

Our review showed floods also affect mental health. The more you’re exposed to floodwaters in your home or business, the worse the mental health impacts are likely to be.

The After the Flood study examined mental health and wellbeing outcomes six months after the 2017 flood in the Northern Rivers. It found people who had floodwater in their home, yard or business, or who were displaced from their home for a more than six months, were much more likely to have probable post-traumatic stress disorder, anxiety or depression, compared to those who didn’t experience flooding or weren’t displaced.

Repeated natural disasters could compound these mental health consequences. Southeast Queensland and the Northern Rivers in NSW have experienced multiple disasters over recent years. The Northern Rivers faced major flooding in 2017, bushfires in 2020, further major floods in 2022, and now Cyclone Alfred in 2025. These repeated disasters have taken a toll on our community, creating a seemingly never-ending cycle of recovery, rebuilding and preparation for the next disaster.

Our understanding of the unique challenges faced by communities which experience multiple disasters is still growing. However, a recent Australian study showed exposure to repeated disasters has a compounding effect on people’s mental health, leading to worse mental health outcomes compared to people who experience a single disaster.

Mums and babies

The health effects of floods extend far beyond the initial emergency and beyond the infections and mental health consequences you might expect.

The Queensland Flood Study tracked pregnant women exposed to the 2011 Brisbane floods. Researchers assessed mothers’ stress related to the flood and tracked them and their children at six weeks old, six months, 16 months, 2.5 years, four and six years. It found some links between prenatal stress and developmental outcomes in children.

While the health effects after flooding are diverse, the research to date is not comprehensive. We need to learn more about how floods contribute to or exacerbate existing chronic illnesses, disability and long-term mental health issues.

The impacts are inequitable

Flooding exposes and worsens existing inequalities. Socially vulnerable groups are more likely to be exposed to flooding in their homes and have less access to resources to respond and recover from these events, putting some groups at higher risk of negative health impacts afterwards.

Some research has looked at the disproportionate impacts on people with disabilities and their carers, First Nations communities and people from disadvantaged backgrounds.

After the 2017 Northern Rivers floods, for example, people with disability and their carers were more likely than others to:

• experience disrupted access to food, support networks and essentials such as health care and social services
• continue to be distressed about the flood six months after it happened
• be at relatively high risk of post-traumatic stress disorder six months after the flood.

However, targeted flood research exploring the experiences of these vulnerable groups in Australia is limited.

Moving forward, it’s vital we examine the varied impacts of flood events for more vulnerable groups, so we can better support them in the wake of devastating events such as Cyclone Alfred.

If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14.

Jodie Bailie, Senior Research Fellow, The University Centre for Rural Health and The Centre for Disability Research and Policy, University of Sydney; Jo Longman, Senior Research Fellow, The University Centre for Rural Health, University of Sydney; Rebecca McNaught, Research Fellow, Rural and Remote Health, University of Sydney, and Ross Bailie, School of Public Health, Honorary Professor, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Retinol skincare products suddenly seem to be everywhere, promising clear, radiant and “youthful” skin.

But what’s the science behind these claims? And are there any risks?

You may have also heard retinol can increase your risk of sunburn and even make acne worse.

For some people, retinol may help reduce the appearance of fine lines. But it won’t be suitable for everyone. Here’s what you need to know.

What is retinol?

Retinol is part of a family of chemical compounds called retinoids. These are derived from or related to Vitamin A, a nutrient essential for healthy skin, vision and immune function.

All retinoids work because enzymes in our skin convert them into their “active” form, retinoic acid.

You can buy retinol in creams and other topical products over the counter.

These are often promoted as “anti-ageing” because retinol can help reduce the appearance of fine lines, wrinkles and even out skin tone (for example, sun spots or acne scars).

It also has an exfoliating effect, meaning it can help unclog pores.

Stronger retinoid treatments that target acne will require a prescription because they contain retinoic acid, which is regulated as a drug in the United States, European Union, United Kingdom and Australia.

How is retinol used in skincare?

One of the most common claims about retinol is that it helps to reduce visible signs of ageing.

How does this work?

With age, the skin’s barrier becomes weaker, making it more prone to dryness, injury and irritation.

Retinol can help counteract this natural thinning by stimulating the proliferation of keratinocytes – cells that form the outer skin layer and protect against damage and water loss.

Retinol also stimulates the production of collagen (a key protein that creates a scaffolding that keeps skin firm and elastic) and fibroblasts (cells that produce collagen and support skin structure).

It also increases how fast the skin sheds old cells and replaces them with new ones.

Over time, these processes help reduce fine lines, fade dark spots and even out skin tone. It can also make skin appear clearer.

While effective, this doesn’t happen overnight.

You may have also heard about a “retinol purge” – a temporary flare of acne when you first start using topical retinoids.

Studies have found the skin may become irritated and acne temporarily worsen in some cases. But more research needs to be done to understand this link.

So, is retinol safe?

At typical skincare concentrations (0.1–0.3%), side effects tend to be mild.

Most people who experience irritation (such as redness, dryness, or peeling) when starting retinol are able to build tolerance over time. This process is often called “retinisation”.

However, retinol increases the skin’s sensitivity to UV radiation (known as photosensitivity). This heightened reactivity can lead to sunburn, irritation and an increased risk of hyperpigmentation (spots or patches of darker colour).

For this reason, daily use of broad-spectrum sunscreen (SPF30 or higher) is strongly recommended while using retinol products.

Who should avoid retinol?

Teenagers and children generally don’t need retinol unless specifically prescribed by a doctor, for example, for acne treatment.

People with sensitive skin or conditions such as eczema (dry, itchy and inflamed skin) and rosacea (chronic redness and sensitivity) may find retinol too irritating.

Using retinol products alongside other skincare treatments, such as alpha-hydroxy acids, can over-exfoliate your skin and damage it.

Importantly, the active form of retinol, retinoic acid, is teratogenic (meaning it can cause birth defects). Over-the-counter retinol products are also not recommended during pregnancy or breastfeeding.

Choose and store retinol products wisely

Since retinol is classified as a cosmetic ingredient, companies are not required to disclose its concentration in their products.

The European Union is expected to introduce new regulations that will cap the concentration of retinol in cosmetic facial products to 0.3%.

These are precautionary measures aimed to limit exposure for vulnerable groups, such as pregnant women, given the risk of birth defects.

It’s therefore recommended to use products that clearly state the retinol concentration is between 0.1% and 0.3%.

Retinol is also a notoriously unstable molecule that degrades with exposure to air, light or heat.

Choosing a product with airtight, light-protective packaging will help with potential degradation problems that could lead to inactivity or harm.

What’s the safest way to try retinol?

The key is to go low and slow: a pea-sized amount of a low-concentration product (0.1%) once or twice a week, preferably at night (to avoid UV exposure), and then the frequency and concentration can be increased (to a maximum of 0.3%) as the skin adjusts.

Using a moisturiser after retinol helps to reduce dryness and irritation.

Wearing sunscreen every day is a must when using retinol to avoid the photosensitivity.

If you experience persistent redness, burning, or peeling, it’s better to stop using the product and consult your doctor or a dermatologist for personalised advice.

Laurence Orlando, Senior Lecturer, Product Formulation and Development, Analytical Methods, Monash University; Zanfina Ademi, Professor of Health Economics, Monash University, and Zoe Porter, Lecturer, Pharmacy and Pharmaceutical Science, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.